Home Gardening jobs April gardening jobs

April gardening jobs

You can’t hide indoors anymore!

Here are your April gardening jobs – with added links if I have more information on the subject. They are all still relevant to do now if you’ve fallen behind or if the weather’s been bad.

Week 1

Stop weeds before they start in earnest. Cover weedy, empty soil with black plastic, cardboard or carpet. On cultivated ground, hoe weeds as they emerge and don’t let them seed. Keep digging out perennial weeds such as bindweed and brambles.

Use Russian comfrey (Bocking 14 strain) to make your own plant food. The leaves can be used as a compost activator, a mulch, or a liquid feed. Bocking 14 won’t take over your garden but the plant food it makes stinks!

Helichrysum, Antirrhinum and sweet mace April gardening jobs
Helichrysum, Antirrhinum and sweet mace

Continue to prick out seedlings. Shade seedlings in the greenhouse on sunny days, as they can quickly wilt and die. Don’t water them with cold water. Keep a couple of cans filled inside the greenhouse so the water is at the ambient temperature.

Top-dress containers. Scrape the top 4cm of soil off and replace with new compost. Finish with a layer of horticultural grit to retain moisture.

Make sure automatic vents in the greenhouse are working and open the door on sunny days. Avoid fungal diseases by watering from below to avoid wetting foliage. Don’t let plants stand in cold water for longer than 10 minutes.

April gardening jobs
Holly blue butterfly on newly painted black garden wall

Feed hedges with a top-dressing of garden compost or well-rotted manure, or mulch with lawn mowings.

Plant evergreen hedges. Prepare the site well, adding a couple of handfuls of garden compost per plant. Water well over the next few months.

Divide overgrown clumps of herbaceous perennials. Water well after transplanting and keep moist in dry spells.

Aster Barbados before division April gardening jobs
Aster Barbados before division

Slugs and snails will become active. Destroy their eggs (translucent milky spheres), laid in nooks and crannies. Delphiniums and newly emerging hostas, in particular, are at risk. Once the soil has warmed up enough, apply the slug nematode. They will get rid of soil-dwelling slugs but not snails. Use all organic controls available.

Aphids will multiply rapidly. Remove early infestations by hand. Protect sweet pea plants, as they can get sweet pea viruses.


Week 2

The soil will be warming up at last, even if you garden on clay. Delay seed sowing in open soil until you can see weeds growing strongly.

Rose James Galway, June 9 April gardening jobs
Rose James Galway

As climbing roses send out shoots, pull them down to the horizontal. This will encourage flowering shoots to emerge.

Get to know what vegetable seedlings look like, so you don’t hoe them off by mistake, thinking they are weeds.

Dig in overwintered green manures three to four weeks before you want to use the ground. Using a sharp spade, turn the plants back into the soil, chopping them up as you go.

Dahlia New Baby, Sept 8 April gardening jobs
Dahlia New Baby

Pot on dahlia and begonia tubers and pinch out tips of fuchsias and other half-hardy plants.

Sow perennials in modules or small pots. Prick out once leaves are large enough to handle. Plant out when well-established. Some perennials may flower this year, others will take longer.

Plant up hanging baskets. This gives them plenty of time to bulk up. Fuchsias prefer shadier conditions, so sit them out of direct sunlight.

Whitefly and aphids on an overwintering chilli April gardening jobs
Whitefly and aphids on an overwintering chilli

Pest populations usually start to increase dramatically now. Be vigilant! Use organic treatments, such as insecticidal until it’s warm enough for biological controls.

Once it’s warm enough, introduce biological controls in the greenhouse. This is one of the most vital of the April gardening jobs. Use the predatory mite Phytoselius to control red spider mite, the tiny wasp Aphidius for aphids and the predatory mite Hypoaspis for control of sciarid fly.

Hard-prune shrubby herbs such as sage, cotton lavender (Santolina), bay and rue to encourage vigorous new growth. Trim old stems from marjoram and savory. Prune lavender, taking care not to cut into the old wood. Offcuts can be used as softwood cuttings. Old, woody plants are best removed.


Runner bean supports made out of Phormium flower stems April gardening jobs
Runner bean supports made of Phormium flower stems

Week 3

Support peas sown last autumn or earlier this year, using twiggy sticks, or wide mesh netting. Prepare runner and climbing French bean supports if you want to save time later in the year.

Deadhead daffodils, but let the leaves die down naturally.

Tie in honeysuckle, clematis and other climbers as new growth starts to sprout.

Clematis montana Elizabeth April gardening jobs
Clematis montana Elizabeth

On variegated plants, prune out shoots that have reverted to green. If left unchecked, they will eventually take over from the variegation.

Perennials should be staked early so they can be tied in before they start to flop. Use prunings from around the garden to make supports.

Feed the soil if the winter has been wet. Use garden compost, or well-rotted manure, around established plants, and in planting holes.

Californian poppy Jelly Beans, August 6
Californian poppy Jelly Beans

The cheeriest April gardening jobs include sowing lots of annuals including Californian poppy, Nigella and poached egg plants, which are good for pollinators.

Tear off rose suckers. Cutting leaves a growth bud but tearing rips it off.

To prevent algae build-up in your pond, add a small bale of barley straw. As light levels and temperatures increase, this triggers algal growth, making the water go green. Have plenty of plants around the sides for moist shelter, essential if your pond is set in gravel.

Mint
Barrel full of mint

Divide clumps of herbs. Plants, such as bay, can be layered now. Refresh herbs in pots by scraping off the top 5cm of soil, topping up with fresh compost and finishing off with a layer of horticultural grit.


Week 4

Wait until the soil is warm enough before planting potatoes – if grass and weeds are growing, it should be fine. If you got off to an early start last month, they may be ready for earthing up – covering the haulms with soil. Do this as the shoots start to show. If frost is forecast, young shoots will need protection even in unheated greenhouses. Earth them up or cover with newspaper, net curtain or horticultural fleece overnight.

Make sure annuals you buy at the garden centre/nursery are hardened off before you plant them out. Half-hardy annuals like Surfinia, petunias, French marigolds and Antirrhinums can’t go outside until the last frosts.

Antirrhinum The Bride
Antirrhinum The Bride

One of the most important April gardening jobs is pruning spring-flowering shrubs such as Forsythia, Ribes (flowering currant), Kerria japonica and winter jasmine. Next year’s flowers will be produced on this year’s stems. Cut back hard now. Wait until summer to prune magnolias such as M. stellata and M. x soulangeana.

Once the soil is warm and still moist, mulch well, to a depth of 6cm. Use leaf mould or home-made compost to suppress weeds and help retain moisture levels during summer.

Plant out sweet peas and tie in if they are tall enough. Provide support with twigs or string or pea netting.

Sweet pea Flamingo Flamenco Mixed, March 24
Sweet pea Flamingo Flamenco Mixed, March 24

Hardy annual seeds can be sown directly into open ground, but wait until you can see weeds growing strongly before sowing.

Take cuttings from young shoots of shrubs. They should root easily.

You can still plant herbaceous perennials such as Geranium, Astrantia and Oriental poppies. Check that they have strong, green shoots and plant them into well-prepared soil.

Astrantia Buckland
Astrantia Buckland, May 28, 2020. Picture; Vanessa Sundin

Divide clumps of herbaceous perennials. Bamboos and clumps of bulbs or rhizomes can be treated in the same way. Make sure that the divisions have roots, shoots, and are given adequate water to settle in.

Prune Penstemon and other slightly tender plants such as Teucrium. Make the cuts just above fresh, new shoots.

Apply a general-purpose fertiliser such as Growmore to borders and beds. Take care not to damage emerging shoots, or to burn them with fertiliser.

Parsley Italian Giant, February 29
Parsley Italian Giant

Place card collars around the stems of brassicas to prevent an attack of cabbage root fly.

Sow pots of herbs such as parsley, coriander and basil.

Cover blossoming fruit trees with sheets of fleece on frosty nights to protect embryo fruit.

Sow seeds of the following veg if conditions are fine: beetroot, parsnips, turnips, onions, peas and mangetout, broad beans, lettuce and salad leaves, spinach, radish, rocket, mizuna, pak choi, cauliflower, cabbage and Brussels sprouts.

For more gardening tasks, see my week-by-week jobs page for March.

April gardening jobs updated June 2022