Guide written by:
John, Passionate gardener, Cambridge
While March tends to be too chilly to get any real work done in the garden, April marks the end of winter and is the perfect time to start all kinds of sowing and planting. That said, gardens may still have to cope with cold spells and frost up to about mid-May. Read on to find out what to plant and sow in April.
- Sun exposure
- Transplanting and planting
- Sowing seeds
- Flowerbeds and borders
- Pots and planters
Sowing seeds in April
The first seeds to sow in April
Swiss chard seeds can be sown in place from April until late May, and should ideally be kept in one spot as this plant tends to bolt if transplanted. Alternatively, you can sow your seeds in pots which will lessen the amount of stress put on the plant when transplanting.
Several varieties of cabbage can be sown indoors or under cold frames. This applies to autumn or winter cabbages (such as green cabbage or Savoy cabbage) as well as Romanesco broccoli and Brussel's sprouts. Each year, your pea and bean seeds will be the first to be sown directly in the ground. Cold-hardy smooth pea varieties can be sown at the beginning of April whereas wrinkled varieties should wait for the end of the month as they require a bit more warmth. Dwarf peas should be sown in rows spaced around 30 cm apart. Any climbing varieties should be spaced around 40 cm apart.
The last seeds to sow in April
Sow your radish seeds every 10 to 15 days to ensure you'll always have some at hand when it comes time to harvest. Salsify and black salsify should be sown at the end of the month in soil that has been given the chance to heat up a bit as these plants can be slow to germinate.
Spinach can be sown in rows spaced around 25 cm apart from late spring to late summer. Leeks should be sown in rows for an autumn harvest.
Parsnip seeds should also be sown in rows spaced around 40 cm apart. They can also be sown in in seedbeds before being transplanted. Beetroot seeds should be sown in a seedbed until about mid-April and transplanted when the plant has 4 or 5 leaves. For a winter harvest, try sowing your beetroot seeds in May instead.
Rocket seeds can be sown in the ground all spring and all summer long. You can sow them in rows or scatter them.
Sowing lettuce, carrot, turnip and herbs
For a summer harvest, sow your carrot seeds in rows (around 25 cm apart) in April. If you want a later harvest, May or June is the perfect time to start.
Lettuce seeds can be sown outdoors, in rows or in seedbeds for most of the year, depending on the type: butterhead and Oakleaf varieties tend to be the most heat-resistant. It is good idea to sow or plant fewer lettuce seeds than you think you may need as we often overestimate how much we'll actually eat. At the same time, lettuce is relatively easy to grow so you shouldn't have any problems having a permanent stock of fresh, crispy lettuce!
Sow your spring turnips in the ground in rows spaced 25 cm apart. April is also a good time to sow annual aromatic plant seeds such as parsley, chervil, dill, coriander, fennel and borage. Perennial herbs or herbal shrubs, including thyme, rosemary, sage, winter savory, bay leaves and mint can all be started in seedbeds.
Swede (rutabaga) and kohlrabi seeds can be scattered or sown in rows in a seedbed.
Transplanting or planting in the ground
April is a good time to split up your artichokes. This process involves removing the smaller, weaker plants at the base of the mother plant and transplanting them to another corner of the garden.
Your lettuce heads can be transplanted once they have grown a few leaves. Plant them in the ground with around 25 to 30 cm of free space in all directions. If you're hoping for a spring and summer harvest, now is the time time to plant your leeks making sure to leave 15 cm between the rows and at least 35 cm between plants.
You have until mid-April to plant Jerusalem artichokes, but be careful when choosing a spot as this plant can be highly invasive! Pretty much any variety of potato can be planted at this point, too, although it is still best to wait until the end of the month in cooler parts of the country. If you are still expecting some light frost, you can always hill up your potatoes with some leaves.
Sowing seeds in warmer areas
Melons and watermelons can be started in pots but will need to be kept above 20°C – which is easier said than done in the UK! If the weather is looking good, you can try to sow your green bean and pea pod seeds at the end of the month.
Sow celery and celeriac in seed beds, when the soil temperature has consistently reached around 15°C. Courgette, summer squash and pumpkin should be sown indoors with two or three seeds per hole. However, these can also be transplanted to a mini greenhouse.
It is tempting to get your vegetables started as soon as possible. However, it is still a bit early to plant peppers, tomatoes and aubergines. If you live in the south of the country, you can try your luck next month.
Greenhouses and accessories
Sowing seeds in cooler areas
At the start of the month, those in cooler areas can still sow seeds of less cold-hardy plants but this will have to be done indoors, under cold frames or in pots in greenhouses. It's a good idea to wait until mid-April to plant your autumn-harvesting squashes (pumpkins, butternut squash, etc.) in pots. Do not be tempted to do this too soon as these seeds develop quickly and you may find your pots getting overcrowded before the plants are ready to go in the ground in mid-May. Remember to transplant any tomato seedlings.
Finally, don't forget to start splitting up plants that have become too densely packed such as tarragon, mint, sorrel, oregano, rhubarb and artichokes. Take the opportunity to transplant them elsewhere or go barter with your neighbours!
Flowers to plant in flowerbeds or borders
Some plants are naturally great at filling any empty or unsightly spaces in the garden. They can be sown directly in the ground, without any protection, and they won't need to be transplanted. These varieties include poppies, California poppies (Eschscholtzia), nasturtiums, marigolds, larkspurs, love-in-a-mists, knapweeds, blueberries, sweet peas, virginia sotck (Malcomia), cone-flowers, summer adonis (pheasant's eye), morning glory and so on.
Here are some varieties that can be sown indoors or towards the end of the month: baby's breath (gypsohilia), marigold and Mexican marigold, sweet William, lupin, snapdragon, beardtongue, Chinese aster, decorative tobacco, carnation, zinnia, verbena and annual lavatera.
Flowers that have sprouted from seedlings or that were purchased in pots should be planted directly in the ground in the latter half of the month. These can include bear's breeches, agapanthus, canna, dahlia, gladioli, lavatera, amaryllis, coppertips, foxglove and russian sag, among others.
Flowers to plant in shady spots
Touch-me-nots are perfectly suited to rich, cool soil. Periwinkle is an invasive, ground-cover plant that is great for embellishing undergrowth, slopes or the shady areas around shrubs. Epimedium, otherwise known as barrenwort, is a perennial flower with strong roots. It is ideal for rocky, shady terrain. Alumroot is a perennial with colourful foliage that produces delicate floral stems that are often used in decorative bouquets. This plant can handle a lot of sun exposure, but will also cope with partial shade. Plaintain lilies are mainly grown for their variegated leaves and have a beautiful summer bloom. While they can be planted all year round – with the exception of cold spells and frosty months – spring is the most favourable season to get started.
Flowers for pots and planters
Flowers in pots, planters, on terraces, balconies or along sunny walls are generally well protected and won't have to deal with low temperatures. These varieties can therefore be sown or planted earlier than those planted directly in the ground. If frost or a cold spell is on the cards, a horticultural cover should be enough to ensure effective protection.
Different flower varieties look great mixed all together in pots. So feel free to combine upright plants like beardtongues, petunias, bell flowers, false goat's beard and pelargonium zonal with hanging plants such as verbena, surfinia, lobelias or waterhyssop. If volume is what you're after go for some twinspur, beeblossom or lantanas.
You can place annual plants, flower bulbs, perennials and even small shrubs in the same container. Of course, you can also grow these flowers in separate pots, alongside many others such as carnations, nemesia, widow's thrill, cranesbills, anemones or coneflowers.
Planting around the pond
Now we'll take you thought some decorative aquatic plants that are perfect for ponds or small lakes. The yellow iris is an upright plant with bright yellow flowers that works perfectly around ponds. These plants can be planted in an aquatic basket both in the autumn and early spring. Lotus and waterlilies can also be planted in spring (as early as April in milder areas). In cooler parts of the country, you'll simply need wait for the water to warm up which may take you up to June. Any plants that are planted using an aquatic basket must be handled with great care. White water-crowfoot can be planted in the sun or partial shade, and can withstand cold temperatures. Most other varieties, however, will have to wait for the water to get warmer as the majority will require full sun exposure.
Choosing the right plants for your rock garden
Sweet alyssum and annual baby's breath seeds can be sown from April onwards. Other rocky garden flowers that can be started this month include mountain alyssum and aubrieta. Some varieties can only be transplanted from pots in April. This includes:
- Mexican marigolds;
- maiden pinks;
- tussock bellflower;
- common houseleeks.
Climbing plants for walls and fences
The stems of some plants will naturally wrap themselves around objects while others grow in spirals, allowing them to climb higher and higher. These plants are ideal for sprucing up a gazebo, fence, trellis, or pergola. One of the most popular climbing plants is honeysuckle, which has fast-growing vines and produces a sweet, heady scent.
Passion flowers have very large, unique flowers, clematis offers a generous blossom in a range of colours and trumpet vines produce beautiful yellow or orange trumpet-shaped flowers. Other climbing varieties that can be started in April include jasmine, climbing nasturtium, sweet peas and morning glory.
Sowing flower seeds, pruning fruit trees, tidying up flower beds, harvesting your seasonal veg… there are plenty of tasks to keep you busy! What's more, these jobs change month by month and season by season. Whether you have a vegetable plot, an ornamental garden or simply a terrace or balcony, follow our gardening guides for tips to keep you going throughout the year.
Guide written by:
John, Passionate gardener, Cambridge, 61 guides
When I was young, I was already working in the family garden. Perhaps that is where my interest in plants and gardening came from. So, it was logical for me to study both plant biology and agronomy. At the request of various publishers I have, over twenty-five years, written many books on the subject of plants and mushrooms (a subject that is close to my heart).They were mostly identification guides at first, but shortly after they were about gardening, thus renewing the first passion of my childhood. I have also regularly collaborated with several magazines specializing in the field of gardening or more generally in nature. There is no gardener without a garden, I have cultivated mine in a small corner of Cambridge for the last thirty years and this is where I put into practice the methods of cultivation that will I advise you in as well.