Fruit & vegetable garden
Flower garden
Glasshouse, conservatory and houseplants
Trees, shrubs, roses, climbers and hedges
Lawns and meadows
Ponds
Wildlife gardening
Garden structures
Gardening for children
Top 10 jobs
1. Keep weeds under control
2. Protect fruit blossom from late frosts
3. Tie in climbing and rambling roses
4. Sow hardy annuals and herb seeds
5. Start to feed citrus plants
6. Increase the water given to houseplants
7. Feed hungry shrubs and roses
8. Sow new lawns or repair bare patches
9. Prune fig trees
10. Divide bamboos and waterlilies
April's weather
Glossary of terms
Cultivar
Earthing up
Foliar feeding
Hoe
Pinch out
Pot-bound
Top-dress
Fruit and vegetable garden
Fruit
Pinch out lateral shoots on grape vines to leave one lateral per 30cm (1ft) of rod. Tie in the selected shoots as they extend along the supports.
Before the buds break on wall-trained figs, look for any badly placed shoots that are growing into or away from the fence or wall and remove them. Tie in the remaining shoots.
Start pruning trained fruit tree forms (such as espaliers, fans and cordons). These forms are pruned when in active growth, to keep down their size and to encourage fruit bud formation.
It is now safe to prune plum and cherry trees, which are vulnerable to the disease silver leaf if pruned in autumn or winter.
Begin feeding citrus plants with a proprietary citrus feed, or using a high-nitrogen feed with added trace elements.
Although blackcurrants, blackberries and hybrid berries should have already been fed in January or February, they benefit from a further feed (30g per sq m) with a high nitrogen fertiliser such as sulphate of ammonia or nitrochalk.
Grape vines on sandy, nutrient-poor soils, may benefit from an application of magnesium sulphate (60g per sq m) or a foliar feed of Epsom salts, to prevent magnesium deficiency.
Plant container-grown outdoor grape vines, once all risk of frost has passed. Vines need deep, well-drained soils with a pH of 6.5-7.
You can still plant container-grown fruit trees and bushes, as long as the ground is not too wet or frozen. Incorporate lots of well-rotted organic matter into the ground before digging the planting hole or trench. Take care to water well in dry weather, as the plants will not have much time to establish before the hot, dry season begins.
If you have still been forcing rhubarb plants under forcing jars, take the last crop of pale stems, feed with general fertiliser, and leave them uncovered to grow without cropping for the rest of the year.
Protect blossom of apricots, peaches and nectarines from frost by covering the trees with fleece. Hand-pollinate the flowers with a fine brush if insects are scarce (a rabbit’s tail is traditionally used).
Control weeds. Hoe shallowly around fruit trees and bushes during dry weather.
Place cloches or fleece over outdoor strawberry plants for an early crop. Make sure to remove the fleece or cloche during the warmest part of the day, to allow pollinating insects to enter. High potassium feeds (such as tomato fertiliser) will also help to encourage flowers and fruit.
Pest & disease watch
Keep temporary shelters in place over peach trees, to protect against peach leaf curl. Nectarines and almonds are also vulnerable.
Keep an eye out for early aphid attack, and deal with this appropriately, either by squashing small colonies, or by using pesticide on larger infestations.
American gooseberry mildew can appear as a brown crust over the leaves and fruits of gooseberry bushes. Spraying with fungicides containing sulphur or myclobutanil is usually effective, but you may wish to grow a more resistant cultivar like ‘Invicta’.
You may need to spray against pear midge, taking care to do so only when the buds are white but still closed. Do not spray once the flowers have opened.
Blackcurrants are vulnerable to big bud mite (affected buds appear larger than normal). The mites can spread blackcurrant reversion virus. Virus symptoms will be evident once the plant comes into flower, as the flowers look red rather than grey. Affected plants must be dug up and disposed of in the rubbish, or by burning. You may wish to grow resistant cultivars such as ‘Farleigh’, ‘Foxendown’ or ‘Ben Hope’.
When carrying out any spraying operation, take care to spray early in the morning when fewer pollinating insects are about - you only need to kill the pests, not the beneficial insects.
Net your fruit crops to reduce pigeon damage, and to keep bullfinches off fruit buds (particularly gooseberries). Nets can be removed once flowering starts.
Apples and pears may need spraying against scab, where this has got out of hand in previous years. Fungicides containing mancozeb or myclobutanil are suitable choices.
Vegetables
Chit and plant out second early potatoes in the first half of the month and maincrop potatoes in the second half. Potatoes can be planted in deep drills or in individual planting holes, with 5cm of soil mounded over the top. Alternatively, plant them through slits in black polythene mulch.
If you live in a very mild area, and got off to an early start with your potatoes last month, they may be ready for earthing up to exclude light and prevent the tubers going green. Start earthing up as the shoots grow, covering them entiriely if frosts threaten, and finishing when the earthed up ridge is about 25cm (10in) high. Potatoes grown under black polythene do not need earthing up, as the polythene excludes enough light. If frost threatens, then cover the shoots with horticultural fleece to protect them.
Sow beetroot, carrots, Swiss chard, summer cauliflower, kohl rabi, lettuce, leeks, radish, turnip, spring and pickling onions, peas and perpetual spinach in well-prepared soil.
Why not try sowing some unusual vegetables such as salsify, Hamburg parsley, or scorzonera, both root vegetables favoured by the Victorians, and still eaten a lot on the Continent.
Plant shallots, garlic and onion sets.
Plant Jerusalem artichoke tubers.
Plant asparagus crowns. A deep, friable, well-drained soil with plenty of organic matter incorporated is ideal.
Broad beans grown in pots can now be transplanted into the garden.
In the second half of the month (wait until early May in cold areas) you can sow marrows, courgettes, pumpkins and squash in a heated glasshouse at a germination temperature of 16°C (61°F).
In very mild areas you may be able to sow dwarf French beans and sweet corn outside under cloches or fleece, but in cooler areas it is best to wait until May.
Sow a seedbed of brassicas to provide transplants of sprouting broccoli, cauliflowers and cabbages that will be ready for planting out to their final position in June or July, and for harvesting in autumn/winter. It is rather late for sowing Brussels sprouts, but you can still buy young plants from the garden centre.
Sweet peppers, tomatoes, cucumbers, aubergines, celery, salads and globe artichokes can all be sown in a frost-free greenhouse. Artichokes and celery can be transplanted outside later in the spring. Tomatoes germinate best at 22°C (72°F), and can either remain in the greenhouse or go outside from early summer onwards. Peppers, cucumbers and aubergines do best kept under cover throughout their life.
Pot up tomato seedlings when they develop true leaves above the more rounded seed leaves. After growing on in small pots, they can be planted into larger pots or growing-bags.
Plant out onions sown from seed earlier in the spring. Don’t use ground used for onions in the last three years.
Pea plants should be supported with sticks, twigs, green support mesh, or wire netting from the garden centre.
Thin out rows of seedlings as soon as they are large enough to be handled.
Fleece and polythene can be used to protect early outdoor sowings. Many vegetables can bolt if sown outside too early without protection (beetroot being an example). A greenhouse or conservatory is useful in all but the very mildest areas with the lightest soils, to start seeds off, hardening off and transplanting the young plants into the vegetable garden later in the spring.
Continue to force witloof chicory and seakale. Dig up selected chicory roots, pot them up, and position them in a dark warm place (10-13°C; 50-55°F), with an upturned pot over them. The tasty chicons will appear in three to six weeks. Seakale is best forced outside at seasonal temperatures, with an upturned pot or cardboard box/tube over the top to exclude the light.
Finish harvesting Jerusalem artichokes, leeks, winter salads, chicory, kale and sprouting broccoli.
Start to harvest spring onions, radishes, spring cauliflowers, spring cabbages and un-forced rhubarb.
Control weeds by hoeing between rows during dry weather.
You could prepare your runner bean supports and trenches for sowing (in May) or planting out (in June). This will save you time later.
Pest & disease watch
Pick yellowing leaves off brassicas promptly, to prevent spread of grey mould and brassica downy mildew. Do not compost such material, but put it in the rubbish, burn it, or bury it deeper than 60cm (24in) depth.
Damping off of seedlings can be a problem with sowings both outside and in modules or containers. Clean equipment and, where necessary, use of fungicides (e.g. Bio Cheshunt Compound) can help to control this problem.
Flea beetle on brassicas can be a problem this month, and you may need to control them with an insecticide or exclude them with horticultural fleece.
Slugs pose a threat, and slug controls are necessary now, as always.
Place mice controls near stored vegetables and ensure that crops remaining in the ground, and new sowings under cloches, are protected from mice.
Pigeons are serious pests of brassicas and other vegetables. Cloches, frames of netting or fleece, and metal cages will help to keep them away from vulnerable crops.
Clear out and clean your vegetable store, to reduce rots and moulds before the influx of new crops.
Attracting wildlife to your garden can help to control pest problems for the coming year.
Insects start to emerge as temperatures increase. A mild spring can see pest problems developing earlier than usual. Current trends in climate change lead to consistently warmer temperatures; it is worth bearing this in mind.
Herbs
Sow basil, parsley, chives, lemon balm, marjoram, sorrel, coriander and dill in the greenhouse or on the windowsill.
It is easier to buy in young plants of mint, tarragon, thyme or rosemary. These are harder to grow from seed, some being prone to damping off, others unreliably producing ripe seed, and others being more quickly and practically propagated by division or cuttings.
Thyme can be propagated by layering, either into adjacent soil, or into little pots buried under the soil surface (for an instant potted plant).
Trim sage plants to keep them neat and to encourage fresh shoots.
Check that clumps of invasive herbs such as mint, lemon balm and even chives, haven’t grown too big for their allotted space. Use a spade to dig out unwanted shoots and runners, or divide them, giving away or transplanting any excess divisions.
Control weeds by hoeing between garden plants and by hand-weeding containers. Weed infested clumps may need lifting to disentangle weeds from the plant roots.
Pest & disease watch
Remove any mouldy or yellowed leaves promptly, to prevent spread of grey mould and other fungal diseases.
Giving plants adequate spacing will help to improve air circulation and reduce the risk of fungal problems.
Look out for pest problems once the weather warms up. Vine weevil can be a pest of container grown plants.
Covering plants with fleece can protect them from flying pests, as well as from the cold.
Flower garden
Divide clumps of herbaceous perennials that you want to propagate, those that have become too large for their allotted space, and those that are flowering poorly or have lost their shape. Bamboos and clumps of bulbs or rhizomes can be divided in the same way. Just make sure that the transplanted divisions have roots, shoots, and are given adequate water to settle into their new positions.
Hardy annuals can be sown in pots or modules to provide colour in the garden. They are inexpensive and can also provide fun activity for children. Suitable examples include Limnanthes, Nemophila, Lobularia and Consolida. There are annual grasses that can be fun to try too: Briza maxima, Lagurus ovatus and Hordeum jubatum are suitable examples. In mild areas with light soil, you can sow directly outside. Marking out irregularly shaped seedbeds and broadcasting ‘drifts’ of different seed gives a more natural look.
Modular trays are useful for sowing half-hardy summer bedding plants such as marigolds (Tagetes), Lobelia, and Petunia. Label each seed tray. You will need to plant them under cover, or in a heated propagator, at the appropriate temperature, only putting them outside when the weather is reliably warm day and night.
If you started sowing early, in March or even February, you may have modules of young hardy annuals now ready for planting out.
When space becomes available in the greenhouse, pot up cuttings of tender perennials taken last summer and at the beginning of this year. Bulk up plant numbers by taking more cuttings from the largest of the new plants.
Sweet peas can be sown outside this month. Fleece covering can be used to raise the temperature and encourage seedling growth in cooler areas, or they can be started off in a cold frame. Some types may need chitting (nicking of the seed coat), and/or soaking, in order to germinate.
Plant out autumn-sown sweet peas that have been raised in pots, and prepare your wigwam supports for them to climb, using a light twine to tie the plants in.
Plant summer-flowering bulbs, if not done already. Prepare the soil first, to ensure that drainage is sufficient to prevent the bulbs rotting. Anemone coronaria tubers, for instance, need particularly well-drained soils.
You can still plant herbaceous perennials such as Geranium, Astrantia and Oriental poppies. Check that the plants you buy have strong, green shoots and plant them into well-prepared soil.
Plan a continuous crop of cut flowers for this summer. Perennials such as delphiniums and annuals can be grown to produce a useful and beautiful display.
Towards the end of the month, in mild areas, you may be able to plant up your hanging baskets for the summer.
Some perennials benefit from having their flowering shoots thinned out. Although this results in fewer blooms, they are larger and of better quality, particularly useful for growing and showing enthusiasts. Delphiniums, lupins and Phlox all benefit from this process.
Put supports in place for perennials before they get too large to manage this easily. It is best to get the supports in early, so that the plants grow up through them, covering them discreetly. Adding rigid supports afterwards usually looks unattractive and results in bunched stems lacking sufficient ventilation. Criss-crossing strings from hidden or decorative posts work well, allowing stems to grow up in the gaps between strings.
Remove faded daffodil and tulip flowers, nipping off the heads and seed pod at the same time.
Deadhead pansies, primulas and other spring bedding plants. Pansies will carry on into the spring and even to early summer, if attended to frequently.
Remove tired winter bedding and plants that did not survive the winter.
Check that self-seeded forget-me-not isn’t smothering other border plants. Pull out plants if necessary.
Prune penstemons and other slightly tender plants such as Teucrium and lavender. Make the cuts just above fresh, new shoots.
Apply a general-purpose fertiliser to borders and beds. Take care not to damage emerging shoots, or to burn them with fertiliser.
Herbaceous perennials infested with couch grass and other perennial weeds should be lifted so the roots of the weeds can be removed. Improve the soil by digging in organic matter before replanting.
Bulbs coming up in the rock garden or in containers may benefit from overhead protection from the rain. A sheet of glass or Perspex placed on bricks will do the job.
However, any winter frost protection and packing should now definitely be removed. Sunlight and air will promote healthy growth.
Top dress spring-flowering alpines with grit or gravel to show off the plants and to help prevent stem rots. Any mulches may need replacing after weed removal.
You could plant up an alpine trough to display some of your alpine plants as many can look their best at this time of year.
Check whether containers need watering. Even at this time of year, they can dry out. Pots that are sheltered by eaves or balconies can miss out on any rainfall. If in doubt, check the compost at a hand’s depth to see if it feels dry. Aim to keep pots moist, not wet, and don’t let them dry out.
Pots and tubs benefit from topping up with fresh compost. Old compost can be removed and replaced with new to a depth of 5cm (2in) if there is not much room for topping up.
Pot on plants showing signs of being pot-bound. You can tip out the rootballs of unhappy looking containerised specimens, to see if they are indeed pot-bound or if they are suffering from some other problem.
Hoe borders to prevent annual and perennial weeds from spreading and seeding themselves.
Perennials that are showing new shoots from the crown can be propagated via basal stem cuttings. Shoots 8-10cm (3-4in) high are cut from the parent plant with a sharp knife. Sometimes a piece of root can be taken with the cutting (which speeds establishment), but stems can be cut without root, and then dipped in hormone rooting powder before striking into growing medium, as for softwood cuttings.
When gardening on wet soils work from a long plank of wood rather than treading on the bed to avoid compacting the soil.
Pest & disease watch
Continue to protect lilies, Delphinium, Hosta and other new shoots from slugs and snails.
Damage to plant roots by vine weevil larvae shows by the plants starting to wilt. On inspection the roots will have been badly eaten, and you may see larvae among them. Apply chemical or biological control if larvae are present, but young and containerised plants are unlikely to recover once badly damaged.
Aphids can multiply rapidly during mild spells. Remove early infestations by hand to prevent the problem getting out of hand. Protect sweet pea plants in particular, as they can get sweet pea viruses, which are transmitted by aphids and other sap-sucking insects.
Watch out for downy mildew and black spot on winter pansies. Remove any infected leaves and destroy badly affected plants. To avoid the build up of diseases, it is best not to plant pansies in the same place year after year.
Remove dead leaves from around the basal rosettes of alpine plants to prevent rotting.
Top dress spring-flowering alpines with grit or gravel to show off the plants and help prevent rotting around the neck.
Glasshouse, conservatory and houseplants
Increase the watering of indoor and conservatory plants as days lengthen. Check if plants need watering at least every few days. Seedlings will need daily attention.
If the weather is warm and sunny, you may need to start damping down the floor of the greenhouse, splashing water over it to increase humidity levels in the whole glasshouse.
On warm days, open vents and doors of greenhouses to reduce humidity and help prevent disease.
Keep alpine houses well ventilated.
Apply a light covering of shade paint on greenhouse panes, to prevent plants becoming scorched by bright sunshine. Alternatively, a sheet of newspaper or some shade netting from the garden centre work fine as temporary shading for seedlings and young plants.
Liquid feed once plants show signs of growth.
Begin feeding citrus plants with a proprietary citrus feed, or using a high-nitrogen feed with added trace elements.
Greenhouse bulbs that have finished flowering (e.g. freesias and Lachenalia) can now be fed weekly with high potassium feed (such as tomato fertiliser), to build up the bulbs before resting them over the summer. Reduce feeding and watering as the foliage starts to die back, and then lay the pots on their sides under the greenhouse bench until next autumn.
Pot up houseplants showing signs of being root-bound or top dress large containers with fresh compost.
Clean shiny-leaved plants with a damp cloth and spiky plants with a soft brush.
Cool conditions and regular watering will help keep potted indoor azaleas looking good for longer. Remember to water azaleas with rainwater collected in a rain butt, not with tap water.
Maintain a minimum of 5°C to prevent Fuchsia, Pelargonium and other tender plants being killed by the cold. Higher temperatures (at least 12°C/54°F) will be needed for tropical plants.
Deadhead Hippeastrum (amaryllis), leaving the flower stalk(s) to die down naturally. Keep feeding and watering, and you may be treated to further flowers in August, as well as the normal blooms next winter. Alternatively, feed only for a few weeks (to build up the bulb) and then reduce the watering, let the leaves die back, and allow the plants to dry out completely. The bulbs can be ‘rested’ like this under the greenhouse bench or in a cupboard if they are houseplants), to be brought out in late summer or autumn, for flowering the following winter.
Rest pot cyclamen that flowered over the winter, reducing watering until the foliage starts to die down. The pots can be placed under the greenhouse bench (or in cupboard if they are houseplants), to be started back into growth in late summer.
Brush up fallen compost and debris, and pick off dead leaves from plants. This will help prevent pests and disease spreading.
Pot up any Begonia, Gloxinia and Achimenes plants that you started off earlier in the spring and are now large enough to re-pot.
Don’t forget to prick out seedlings before they get too crowded, and then to pot them on as individual transplants as soon as they are large enough.
Take leaf cuttings of Streptocarpus plants.
Hydrangeas and fuchsias can be propagated from softwood stem tip cuttings.
Try growing on plug plants in your glasshouse. They are a relatively cheap source of large numbers of plants, and avoid the need for propagation facilities and time-consuming pricking out.
Don’t forget to give glasshouse plants more space as they put on new growth. This will help to prevent disease, and to contain early pest infestations.
In warmer areas, you can probably put away the glasshouse heater. But remember that temperatures can still drop at night. Last year we had frosts until late May in southern England. Seedlings in particular object to wide temperature fluctuations. A heated propagator could be a cost effective answer if your glasshouse is otherwise full of hardy mature plants.
In reliably mild areas you can start to harden off half-hardy bedding plants that were started off early under cover. By placing them outside for a short period only, at the warmest time of day, and then gradually increasing the length of time until they are outside permanently, you can avoid the shock that they otherwise experience when moved outside suddenly.
Clear leaves and twigs from guttering on greenhouses and sheds.
You could use spare space in the glasshouse to warm up grow-bags ready for planting.
Pest & disease watch
Brush up fallen compost and debris, and pick off dead leaves from plants. This will help prevent pests and disease spreading.
Damping off of seedlings can be a problem with sowings under glass. Clean equipment and, where necessary, use of fungicides such as Bio Cheshunt Compound can help to control this problem.
Insects start to emerge as temperatures increase. A mild spring can see pest problems developing earlier than usual.
Trees, shrubs, roses, climbers and hedges
Mulch rose and shrub beds with a 5-7.5cm (2-3in) layer of organic matter. This will help retain moisture during dry spells, reduce weed build-up and over time improve soil structure. Pay particular attention to mulching around rhododendrons, azaleas and camellias as flowering is impaired if they are allowed to dry out during late summer.
Tie in climbing and rambling roses as near to horizontal as possible. This will restrict sap flow causing more sideshoots to grow along the length of stem. Therefore more flowers will be produced.
In colder northern regions, and early in the month, you can still move and plant evergreen trees and shrubs, provided the soil is not waterlogged. They are best moved or planted once actively growing and when there is less risk of cold. In warmer regions, it is best to wait until the autumn, as the weather will soon turn warm and dry, and the plants will have trouble establishing.
In colder areas, you can also still plant container-grown deciduous hedging plants, shrubs, trees and climbers. Stakes and rabbit guards should be put in place at the time of planting to prevent damage to the rootball and bark. Remember that watering and establishment may be problematic as the weather gets warmer and dryer, and you may be better planting in October.
Feed trees, shrubs and hedges with a balanced fertiliser (such as Growmore or blood, fish and bone), sprinkling it over the root area before hoeing into the soil surface. This will particularly benefit young, weak, damaged or heavily pruned plants.
If not completed last month or before, winter-stemmed shrubs such as Salix and Cornus can still be cut back at the beginning of the month. Prune back hard all the previous year's growth to within 1-2cm (0.5-0.75in) of the framework.
Other shrubs that are routinely stooled (cut back hard) in spring, to keep their larger or more brightly coloured juvenile foliage (such as Cotinus and Sambucus), can be cut back this month. You can leave a couple of branches un-pruned if you are reluctant to lose all the height gained last year.
Delay pruning spring-flowering shrubs such as Forsythia and Chaenomeles until after they have finished flowering, otherwise this year's display will be lost.
Remove any frost damaged shoots from evergreens damaged by earlier cold weather.
Remove any reverted green shoots on hardy variegated evergreens, to prevent reversion taking over.
Lightly cut back lavenders to prevent them getting too leggy and woody. Treat Helichrysum (curry plant) and Santolina (cotton lavender) similarly.
Loosen any tree ties that are digging into the bark, or could do so soon as the trunk girth expands.
Take cuttings of your favourite conifers.
Twining climbers (such as honeysuckle and Clematis) need regular tying in and twining around their supports.
Check hardwood cuttings taken last year. They may need planting out or potting on.
Layering is a good way to propagate climbers and lax-stemmed shrubs. Layers should root by next spring, especially if attention to watering is given during dry weather. Examples to try include Philadelphus, Forsythia, Hydrangea and Lonicera.
Pest & disease watch
Bracket fungus on trees is more visible at this time of year. If the tree is in poor health it is worth calling in a tree surgeon for a professional opinion.
Phytophthora root rots can cause die back on mature trees and shrubs. Wet winter weather and poorly drained soils are likely to encourage this problem on susceptible woody plants.
Check for damage or cankers on deciduous trees.
Be aware that insects emerge as temperatures rise. Caterpillars, aphids, and other fly pests may all become problematic during mild spells. Early infestations can often be managed by hand removal, making insecticides unnecessary.
Put rabbit guards around newly planted trees and shrubs to protect the bark.
Avoid planting new roses in areas where roses were previously growing otherwise the new plants may suffer from replant disease.
Inspect sick looking box and holly trees for signs of blight.
Lawns and meadows
Mow lawns when necessary - whenever the grass is growing - the aim is to maintain a constant height throughout the year.
Add the clippings to the compost heap in thin layers (too much grass all at once is likely to be very wet and poorly aerated, resulting in smelly slime rather than compost).
Cut the lawn edges with a half-moon edging iron to ensure they are neat and well shaped.
Use a half-moon edging iron or spade to create a 7.5cm (3in) ‘gutter’ around the lawn edge. This will prevent grass creeping from the lawn into borders.
Sowing new lawns or over-seeding dead patches can be carried out from mid-April to early May. If the soil is very wet or cold germination will be poor, so delay until the weather improves. Prepare the ground for sowing, by cultivating, levelling and lightly firming beforehand.
Do not walk over or mow newly sown grass until it has reached a height of 5-7.5cm (2-3in), and then only give it a light trim at the highest setting.
Apply a high nitrogen spring lawn fertiliser at the beginning of the month to encourage good, strong growth. If moss is a problem choose a combined fertiliser and mosskiller.
April is the best month to apply lawn weedkiller.
Lightly rake lawns with a spring-tine rake to remove old plant debris. This can also be done to rake out dead moss a couple of weeks after applying a chemical moss killer.
Repair bumps and hollows by peeling back the turf, removing or adding soil, and then replacing the turf.
Do not walk on newly laid turf, and leave it undisturbed for several weeks so that the new roots can establish.
Newly turfed areas can be mown with the blades set to the highest setting, as soon as the grass reaches 5cm (2in) in height.
Why not sow a wildflower meadow.
Troubleshooting
With total hosepipe bans likely in many areas this summer, you may consider keeping your lawn a little longer than usual, and even investing in a mulching mower. Mulching mowers shred the grass clippings very finely and then blow them into the lower layers of the turf, where they act like mulch to help the lawn retain moisture. Because the clippings are fine, the end result is not unsightly, especially later in the season when the lawn gets very dry, and the mulch helps to keep it green rather than brown.
If moss is a problem, choose a combined fertiliser and mosskiller when feeding the lawn.
April is the best month to apply lawn weedkillers.
Lightly rake lawns with a spring-tine rake to remove the dead moss a couple of weeks after having applied a mosskiller.
Disperse dry worm casts with a hard-bristled broom or besom.
Molehills are often a problem in spring, as the creature tunnels in search of food. Traps are the most effective way to deal with this problem.
Ponds
Divide or cut back marginal and bog garden plants if overcrowded.
Contain vigorous pond perennials by planting them in aquatic plant baskets and topping with a layer of gravel to prevent fish stirring up the compost.
Small plants in baskets can be raised up on bricks when first introduced then slowly lowered to the bottom of the pond as they increase in size.
Divide and replant waterlilies once they show signs of growth.
Feed large aquatic plants by inserting slow-release fertiliser tablets well below soil level around the base of the plant. Waterlilies are also big feeders. Feed any plants not being divided.
Clean out pond filters.
Start feeding the fish. Little and often is best, to prevent excess food leading to unwanted algal blooms.
Tidy up plants in the bog garden, and mulch with composted bark (or similar).
You could take the opportunity to dig a new pond - the spring rains may even help to fill it. We recommend a minimum depth of 60cm (2ft) at the deepest point, to reduce the risk of the pond freezing to its full depth. Gently sloping contours between the shallow and deep areas, and between the bank and the water, are more wildlife-friendly, and help make marginal plantings appear natural. Our RHS members’ advisory service can advise on suitable liners and construction materials, as well as on how to address health and safety concerns.
Troubleshooting
Drain and clean neglected ponds if black and sludgy. This is not a remedy for algal problems.
Grille coverings (either simple meshes or bespoke features) can protect young children from accidents. The size of the mesh can be judged in order to prevent hazard, but to also allow access for wildlife, and to preserve the aesthetic appeal of the pond.
Monitor the water level of your pond, as defects in liners and concrete structures may have developed and need repairing.
New or recently cleaned ponds can suffer problems with algae. Providing some shade can help reduce this problem. Ironically a covering of Lemna (duckweed) can provide sufficient shade to help suppress the algae until cultivated aquatic plants establish sufficiently to suppress the duckweeed’s proliferation. Other helpful measures include filling the pond with rainwater rather than with tap water, avoiding contamination of the pond with soil or compost (as these encourage algal growth), and taking care to remove plant debris from the water promptly.
Wildlife gardening
Jobs for the month
- Top up bird feeders and put out food on the ground and bird table
- Avoid chunky foods that could choke young fledglings
- Keep the bird bath topped up
- Regularly clean the bird bath and table
- Put up a bat nesting box
- Put out hedgehog food
- Make the pond more wildlife friendly
- Plant annuals and perennials to attract insects
- Put out log, twig and/or rock piles to create shelter for wildlife
- Sow or plant a wildflower meadow, and mow newly established meadows
- Buy and hang a bee nesting box
Birds
The nesting season is now well under way. The dawn chorus can be deafening. Migrant birds from Africa (such as willow warblers, housemartins, swifts and swallows) have now joined the breeding frenzy.
Do take care of your hygiene around birds, as bird ‘flu has reached this country and the rest of Europe; see www.rspb.org.uk or www.defra.gov.uk/animalh/diseases/notifiable/disease/ai/index.htm for further information. Make sure that wild bird droppings are not allowed to accumulate on lawns and surfaces, and wear gloves, long sleeves and trousers, plus a mask when handling them. Obviously, if you keep pet birds or chickens, you are advised to keep them completely separate from potential contact with wild birds, and to mind your hygiene when handling them, wearing suitable protective clothing that is kept solely for this task.
Avoid peanuts and large chunks when putting out food for the birds, as there is a risk that large pieces could be fed by adults to their fledglings, and this could result in choking. Safe foods include wildbird seed mixes (but not those containing peanuts or dog biscuit); black sunflower seeds (the birds will remove the outside casing, and the inner seed is soft); mild grated cheese; sultanas, raisins and currants (best soaked overnight); pinhead oatmeal; apples, pears and other soft fresh fruit; mealworms and waxworms. Alternatively, you can buy fat balls from many garden centres and bird food suppliers. This is an easy alternative, and you can be confident that you will be doing no harm.
To maximise the numbers of different bird species that you attract to your garden, it is a good idea to cater to their different feeding habits. Hanging bird feeders attract species such as tits, finches and sparrows. There are many models available, designed to help keep out rats, cats, pigeons and squirrels, or to fit onto walls, windows, windowsills and balconies. Bird tables attract robins, house and tree sparrows, doves, pigeons, bullfinches, greenfinches, chaffinches and bramblings. Food scattered on the ground attracts blackbirds, thrushes, dunnocks, wrens, fieldfares and redwings.
Hanging bird feeders are best sited over a paved or decked area, which can be regularly swept clear of debris. This may help to reduce problems with rats, if they prove a nuisance.
Bird tables are best sited a few feet clear of cover or high vegetation, so that cats and other predators cannot launch themselves onto unsuspecting feeding birds. They can be quite close to the window or patio, as many birds seem to get used to human activity, and are unlikely to be put off by coincidental human activity.
A birdbath can be a vital source of drinking water for birds. Ensure that yours is kept topped up. Models are available to attach to windows, walls and sills, if you are limited for space. Do be aware of hygiene: change the water regularly and scrub the bath out with a mild detergent (available from bird food suppliers) to help prevent the spread of disease.
Mammals and amphibians
Many garden mammals have given birth to young, and you may spot baby wood mice, shrews or voles, and even fox cubs (most likely in the evenings).
Bats come out of hibernation and start their own nesting season this month, often in the eaves or behind the weatherboarding of south-facing buildings. Why not put up a bat box on a sunny wall? Many bat species are garden-friendly, eating the midges and tiny insects that cause annoyance on summer evenings.
Hedgehog food is now available for sale. It is not a good idea to feed hedgehogs with bread and milk, as this is not their natural diet. Good quality cat or dog food, or raw minced meat mixed with a raw egg make good alternatives.
If you want to make an existing formal pond more wildlife-friendly, you could phase out the fish, add ‘steps’ to counteract steep sides (so that birds, mammals and amphibians can enter and exit more easily), soften the edges with marginal planting (which will also provide hiding and breeding places for wildlife), and introduce a few native species to an otherwise exotically planted pond. Suitable examples are marsh marigold (Caltha palustris), water mint (Mentha aquatica) and yellow flag iris (Iris pseudacorus). Be aware that native species can be more vigorous than some non-native species, and regular cutting back or division is therefore advised.
Insects
Butterflies emerge as temperatures rise and sunshine increases - brimstones, commas, tortoiseshells and early cabbage whites.
Honesty (Lunaria annua or the perennial Lunaria rediviva) is a good plant for attracting butterflies at this time of year, especially if planted near other insect-attracting species.
Gardens with some nooks and crannies, and a few areas where debris is allowed to accumulate (perhaps a woodland area or a meadow within a more formal design), are often more insect-friendly than those composed entirely of paving, pots, lawn and bedding displays.
You may start to see bumble bees on warm days.
Remember that insects are gardeners’ friends as well as foes! They are natural pest controllers, and will keep each other’s populations down to manageable levels once your garden has got back into a natural balance.
As a very general rule, single flowers attract more insects than double blooms. Bear in mind that insects can be attracted to a particular plant for its nectar (Sedum spectabile), its pollen (Lavatera), the shelter it provides (many ornamental grasses and other species) or its suitability for breeding (many native trees, shrubs, climbers, or weeds, such as the common nettle). A variety of insect-friendly planting fulfilling all these needs is likely to attract many more insects than is a mass planting of a single species fulfilling only one.
Bee homes are now widely available. Initial reports suggest that nesting boxes for colony-forming bees (such as bumble and honey bees) are not always effective, but homes for solitary bees (such as mason bees), made from tubes and tunnels in boxes, are more successful. They are also attractive. Models with a backing are more successful than those open at both ends. This kind of bee house is easy to make at home. Even a tin can filled with straws will do the job. South-facing positions, hanging at chest height or above, are best. Bees usually colonise these homes in spring, hibernating over winter to emerge the following spring. The boxes can be left out over winter, or taken down and stored in a safe place to avoid bees being eaten by predators.
All wildlife
Put out log and twig piles made from old prunings and felled trees. These provide valuable shelter for wildlife, and can be made into attractive features by planting up with ferns, primroses, or other suitable plants. A site well away from the house should ensure that unwanted creepy crawlies do not stray into domestic rooms.
Piles of slabs or rockery stones will act as a suitable wildlife habitat, as will old bales of straw, hay or prunings.
Corrugated iron or plastic laid on the soil can provide ‘tunnel’ hiding places for small reptiles and mammals looking for shelter and warmth.
You may wish to identify a suitable part of the garden to leave untouched as a wildlife area. A small patch behind a shed is perfectly fine if you’re worried about it looking untidy.
Plants
Why not sow or plant a wildflower meadow. You should prepare the ground, if you did not do so last month. You will need to create a seedbed if you wish to sow wild flower seed. Annual cornflower seed mix gives an instant display in the first year. Perennial seed mixes take two years to flower, and may be less dramatic in their appearance. An alternative is to spray a weed killer containing glyphosate, on patches of the existing grass. Plug plants can be sourced to grow on, and to then plant in the bare patches. This will only work where the existing grass is not very vigorous. Ryegrasses can overwhelm meadow flowers. If you do have ryegrass, another option is to over-seed with yellow rattle. This is an annual parasitic plant that can be sown directly on to grass, gradually weakening it, and hopefully self-seeding from year to year, producing pretty yellow flowers.
Newly sown perennial meadows should be mown about six to eight weeks after sowing, when they reach a height of 5-10cm (2-4in), and then again every couple of months in their first year, removing the cuttings each time. This helps to control weeds and to toughen up the meadow plants. A stronger healthier meadow will be the end result.
Garden structures
Use a stiff-bristled brush or pressure washer to remove algae from paths. A proprietary algae killer may help.
Remove dirt and algae from walls, paving and patios. Pressure washers can be rented if necessary.
Check and repair pergolas, arbours and arches if needed.
In dry spells, you can treat timber structures with wood preservative and stain. Only do this in a well-ventilated space, to reduce the risks to your lungs and eyes. Make sure you use appropriate products. Creosote, for example, is no longer legal.
Install decking or other seating areas for summer use.
Go through your shed and remove any old, out-of-date garden chemicals. If in doubt of how to dispose of them, your local authority tip should be able to help. You can check our list of chemicals removed from the market for up-to-date information.
Gardening for children
As well as being able to take part in many of the above activities, here are some extras especially for them.
Children attracted to messy and thrillingly disgusting tasks can be shown how to spot and squish early aphid infestations. They can rub off greenfly and blackfly from shoot tips. If children get used to such tasks form an early age they are less likely to develop the squeamishness increasingly common in urban children more accustomed to playstations than the natural world. Familiarity with wildlife engenders less disgust and more interest, and ‘creepy crawlies’ become objects of fascination rather than ‘dirt’. Older children may wish to think about why the aphids are being killed, different methods of controlling them, how they feel about this personally, and the wider implications of choices made by gardeners, with links to conservation issues that form an increasingly large part of the National Curriculum in schools.
Children can help plant onion, garlic and shallot sets. Small children can place the bulbs at an appropriate spacing in drills made by an adult or older child.
Children can sow or plant a containerised herb garden to care for personally. Basil, parsley, chives, lemon balm, marjoram, sorrel, coriander and dill can all be sown or planted in window boxes or pots in the greenhouse. The easiest from seed are chives, basil, lemon balm, marjoram and sorrel. Coriander and dill tend to bolt (set flower and seed prematurely), and parsley can be very slow to germinate without bottom heat. Other herbs, such as mint, are easily divided for an instant and satisfying pot garden.
Anti-tetanus vaccinations are essential where children are in contact with soil; ask your GP.