April is a busy time in ornamental and vegetable gardens in the UK, as lots of seeds should be sown this month. Now the days are longer and reliably warmer, April is the month to make tentative sowings of some seed outside, while others can be started under glass to be planted out after all risk of frost has passed.
In the vegetable garden, crops such as carrots and peas can be sown direct outside, while tender crops like sweetcorn and courgettes should be sown under cover and kept in either a greenhouse or sunny windowsill before planting out the following month. April is also the month for planting potatoes, as well as onions sets, shallots and garlic, and Jerusalem artichokes.
In the ornamental garden, annual climbers like canary creeper (Tropaeolum peregrinum) and Spanish flag (Ipomoea lobata) can be sown now for summer container displays, while others like cosmos and field poppies can be sown to fill gaps in borders.
We’ve picked a selection of vegetable and flowers to plant in April.
Vegetables to plant in April
Aubergines, chillies and tomatoes
April is your last chance to sow aubergines, chillies and tomatoes, which need a long growing season to do well. Keep them on a heated propagator to speed up germination or, if time is tight, wait until next month and buy ready-to-plant plug plants from the garden centre.
- Buy aubergine seeds from: Suttons, Thompson & Morgan, Dobies
- Buy chilli seeds from: Suttons, Dobies
- Buy tomato seeds from: Suttons, Thompson & Morgan, Dobies, Gardening Direct, Crocus
Beetroot is an easy crop to grow, making it ideal for beginners. It will grow in any fertile, well drained soil and also does well in pots (in pots, choose varieties that are less prone to bolting as these will tolerate the drier conditions of a pot better than others). Follow the spacing instructions on the packet and thin the seedlings to about 10cm when they are around 3cm high. Harvest when the beetroots have reached the size of a golf ball.
Sow carrots on well-prepared soil that’s free of stones – stony soil can result in forked carrots. Carrots also grow well in containers – choose short, round varieties, or harvest longer varieties as baby carrots.
At this time of year, it’s a good idea to protect against carrot fly, by putting up a barrier, such as horticultural fleece, around the crop. Find 10 ways to deter carrot fly. Your crop should be ready to harvest three to four months after sowing.
Celeriac needs a long growing season for an autumn/winter harvest, so sow now, under cover. Transfer the seedlings to individual pots when they’re large enough to handle.
Courgettes, squashes, and cucumbers
Courgettes, marrows, squashes, cucumbers and pumpkins are known as curcurbits, and can all be sown in the same way – in individual 5cm pots, under cover. Plant outside once all risk of frost has passed (cucumbers do best in a greenhouse).
- Buy courgette and marrow seeds from: Suttons, Crocus
- Buy pumpkin, squash and courgette seeds from Thompson & Morgan
- Buy cucumber seeds from: Suttons, Gardening Direct
- Buy pumpkin and squash seeds from: Suttons, Dobies
For an autumn harvest, leeks can be sown in shallow drills direct in the ground from April, or in seed trays under cover to plant out later.
Lettuce is best sown under cover, in seed trays or modules, and planted out when large enough to handle. This can give them a head start on slugs and snails, which seem to find young lettuce growth irresistible. Alternatively, sow lettuces in pots, and protect the seedlings using copper tape or by hand-picking slugs and snails when you see them.
Peas are easy to grow and can be harvested early in summer, making them a welcome early crop. You can sow them direct outside, but they are a favourite snack for mice – if these are a problem, sow them indoors and plant the plants outside when they are 15cm tall. Alternatively, sow in guttering and transplant the whole row of seedlings into a trench when they’re ready.
Radishes make a fast-growing ‘catch crop’, growing on ground that’s empty for a few weeks or between slower growing crops, such as parsnips. They also grow well in pots. Sow direct, every three to four weeks, for a continuous supply throughout summer.
Spinach can be sown directly outside in April, but if it’s chilly, hold off until May or cover with horticultural fleece. Bear in mind that spinach needs lots of moisture and protection from slugs and snails.
Swiss chard is a beautiful crop for a sunny or partially shaded spot and can be sown directly outside in April.
Turnips are also quick-growing, being ready to harvest from just six weeks. They can also be grown in pots. Harvest them when they are around the size of a golf ball, for the best flavour, or eat the leaves as greens. Keep well watered.
Flowers to plant in April
This short-lived, majestic perennial is perfect for providing height at the back of beds and borders. Sow under cover from March to May and transplant when all risk of frost has passed. You’ll have beautiful crimson umbels from May to September, which will be covered with bees and butterflies. You could also try sowing Angelica archangelica, from May onwards.
- Buy Angelica gigas from Dobies
Tobacco plant, Nicotiana
Nicotianas have a seductive fragrance, which is especially pronounced at night. Sow seed in March and April, then, after all risk of frost has passed, plant out in their final position around seating areas, to enjoy the scent on summer evenings. Nicotiana sylvestris has elegant, drooping flowers, while those of Nicotiana alata ‘Tinkerbell’ are an attractive terracotta colour.
Several types of poppy can be grown from seed, including orange California poppies (Eschscholzia californica), field poppies (Papaver rhoeas) and larger opium poppies (Papaver somniferum). They can all be sown from March to May, for flowers in summer and autumn.
Bunny tail grass
Aptly known as the bunny’s tail grass, this Lagurus ovatus is a pleasing partner to other annuals and perennials like Verbena bonariensis. Sow indoors, in pots or trays sited in a warm place. Alternatively, direct the sow the seeds outdoors from April onwards, where you want them to flower.
This spectacular perennial, here Monarda didyma ‘Cambridge Scarlet’, can be sown from late winter to spring. Keep the soil moist and cover the seeds to stop them drying out. Pot up the seedlings when large enough to handle, then plant out in full sun or partial shade.
Spanish flag, Ipomoea lobata
Spanish flag is a vigorous annual climber, producing cascades of fiery red and yellow flowers, which look fantastic in annual container displays. Sow it under cover from March to May, then plant out after the last frosts.
Fruit to plant in April
Strawberry runners can be planted in April, and will fruit within a few weeks. Plant them in the ground in rows or in a bespoke ‘strawberry pot’ or hanging basket. Protect developing fruit from slugs and snails using straw.
While bare-root planting season is over, potted fruit trees and bushes such as currants, gooseberry, fig and citrus trees can be planted at any time of year. Many dwarf fruit trees are suitable for growing in pots – choose a large container and use a soil-based compost, water the tree more regularly than you would if planting in the ground and top-dress with fresh compost each spring.