The 5 Seeds You MUST Sow in Spring

Mid-spring is the most important sowing period of the year. Get it right, and you’ll set up your garden for success all summer long. Here’s which seeds to sow in April to avoid missing this important sowing window!

Carrots

Let’s start with one of the most iconic vegetable garden favorites of them all: carrots! Carrots may be one of the cheapest vegetables you’ll find at the supermarket, but they cannot compare to that insanely concentrated, homegrown carrot taste.

Carrots are happiest when they’re sown directly into the soil, then left well alone. They really don’t enjoy being transplanted, and if you try, they can respond by growing in all sorts of weird, wonderful and sometimes downright rude shapes!

Preparation is everything. Clear your growing area of stones and rake the soil to a fine, crumbly texture. If your soil is very heavy or stony, growing carrots in raised beds, containers, or even purpose-built carrot planters can make a huge difference.

Mark out a shallow drill about half an inch (1cm) deep, and space additional rows roughly 8in (20cm) apart. The seeds are tiny. Some people get around this by thoroughly mixing the seeds with a handful of dry sand, then taking pinches of that to sow. But, with a steady hand and a no-rush approach, I’m not convinced this is really necessary.

Take a scant pinch of seeds and carefully sow the seeds into your drills. Cover them back over with soil, and then water along each row. If you’re sowing carrot seeds into dry soil, my top tip is to water into the drill before sowing to make sure there’s enough moisture around the seeds to help them germinate.

Carrots take 10 to 20 days to germinate, so the most important job from this point on is to keep the soil consistently moist. If it dries out below the surface the seeds may never germinate, so keep a close eye on your soil and be on hand with the trusty watering can if needed.

Slugs absolutely love carrot seedlings – in fact, I reckon young carrots are their absolute favourite meal! – so set up your favourite slug control strategy as soon as you sow.

Once the seedlings have germinated, thin them out by removing excess seedlings until there’s roughly half an inch (1cm) between each seedling. Continue to water well in dry weather, and remove any weeds.

Zucchini

Next up, zucchini – the plants that keep on giving! These are among the most productive vegetables you can grow, and they go from seed to sprawling plant in what feels like the blink of an eye. Three or four plants is usually plenty for a small family. That said, I can’t get enough of them so will be growing at least six, maybe eight plants, which I’ll harvest when they’re still quite small because that’s when they’re at their densest and nuttiest.

Sow early at your peril - zucchini is incredibly quick growing! In fact, one summer I had my first zucchini before the end of May from an early April sowing – so within about six or seven weeks. They really don’t hang about! Sow under cover three to four weeks before they’ll be planted outside, which must be after your last frost date. There’s little point sowing earlier than this because you’ll only have to juggle valuable indoor space while you’re waiting for conditions to be warm enough to plant.

Sow each seed into its own small pot or large plug tray cell filled with all-purpose potting mix. Simply dib a hole with your finger and pop the seed in and cover it over with more potting mix. And that’s it! There’s some debate about whether sowing these big seeds on their edge as opposed to horizontally, on their flat sides, reduces the risk of rotting. Possibly, if you’re sowing at the wrong time of year – but in the warmth of spring, I’m not sure it makes much difference.

Zucchini needs warmth to germinate, so keep them somewhere reliably warm and (once they’ve germinated) bright is a must. They’re okay in a frost-free greenhouse or cold frame, or you could keep them on a warm indoor windowsill if the weather’s still a bit cool. Once the seedlings appear they grow fast, so if their roots fill the pot you can pot them on into progressively bigger containers until all risk of frost has passed and it’s safe to plant them out.

When the time comes, plant them into rich soil in a sun-kissed spot; think of them as reclining Greek goddesses! Give them plenty of space and, of course, keep them well watered to encourage fruiting and minimise the risk of mildew. After that, your main task will be harvesting regularly – or else!

Cucumbers

Although a close relatives of zucchini – they’re both in the squash family – cucumbers are just that little bit more particular. They really appreciate warmth, especially early on, so in most climates you’ll need to keep the sown seeds indoors to germinate, just to be on the safe side.

Just as for zucchini, sow one seed per plug or pot of fresh potting mix. They’ll germinate quickly in warm conditions and soon start producing those big, floppy leaves that tell you they’re ready for more space.

For the best, most reliable results, especially if growing undercover, choose a variety that doesn’t need to be pollinated in order to set fruit. And consider growing an all-female variety, because these will produce more fruits.

This year I’m planning to grow cucumbers both outside up teepees of canes, and in the greenhouse. I’m always amazed by how much cucumbers cost in the supermarket, but when you grow them yourself, they’re second only to zucchini in terms of fruiting fanaticism! I love them in smoothies – they’re meant to be incredibly good for your skin and eyes and whatnot – and have you ever tried them in a smashed Asian cucumber salad? It’s insanely good!

Whether you’re growing cucumbers in a greenhouse, hoop house, or a sunny and sheltered outdoor spot, the key things to remember are steady watering and regular feeding. Inconsistent moisture is the quickest way to end up with bitter-tasting fruits – and no one wants that after months of careful nurturing.

With a little attention, cucumber plants will reward you with a steady supply of crisp, refreshing fruits, right through summer.

Swiss Chard

Chard is one of my favourite vegetables for sheer reliability and nutrient-packed goodness. It’s colourful, deliciously productive, and far more tolerant of heat – and cold, for that matter – than many other leafy greens.

Sow two chard seeds into each plug, just to be sure. Unlike spinach, which bolts (flowers and goes to seed) in response to heat, with chard it’s the opposite – cool temperatures early in the plant’s life can increase the risk of bolting. Because chard is a biennial that flowers in its second year, if you sow it to early it might be tricked into thinking a cold snap is, in fact, a full winter, triggering it to send up flowers rather than lots of lovely, luscious leaves.

Plant your chard seedlings a little over a foot (35cm) apart each way once they’re a few inches tall. Keep them well watered to prompt them to produce plenty of leaves. Once they’re well grown, start harvesting the outermost leaves regularly and plants will continue producing for months, giving you fantastic value from just one sowing.

Chard is also a great crop if you’re short on space. It’s happy in containers and looks surprisingly ornamental mixed into flowerbeds too.

Celery

Celery has something of a reputation for being difficult to grow, but really it just likes things done properly. Don’t we all?

The seeds are tiny – almost dust-like - and need light to germinate. Sow them on the surface of premoistened and sifted potting mix, gently pressing them into the potting mix. Don’t cover them.

They’ll need warmth, patience and a bit of faith – celery seedlings are in absolutely no hurry! Secure a clear plastic bag over the top of the pot with an elastic band to create a snug, humid environment which these delicate and dainty seeds will love.

Once they’re up, remove the cover, and when they are big enough to handle pot them on and grow them steadily until it’s time to plant out.

Celery needs rich soil and consistent moisture throughout the season. Let it dry out and the stems will quickly become stringy and strong-flavored – but keep it happy, and you’ll end up with crisp, aromatic stems that are leagues ahead of anything you’ll find in the supermarket. In my garden, there’s a natural spring in one area which causes the soil to be be too wet for most vegetables, but it's just perfect for celery.

Plus: 3 Vegetable Garden Flowers

No springtime sowing list would be complete without a few vegetable garden-friendly flowers to attract beneficial bugs of every size, shape and colour – from poster-girl pollinators like bees and butterflies, to pest-obsessed predators such as hoverflies.

French marigolds will help to confuse pests, sweet alyssum forms a low, fragrant carpet that attract sbeneficial insects of all kinds, while zinnias bring bold colour – plus they make excellent cut flowers.

Sow them into trays or small pots, and keep them frost-free. In just a few weeks they’ll be ready to plant out to add colour, movement, and a healthy buzz to the garden.

This is a time full of promise: every seed sown now is a little vote of confidence in the season ahead! For exact sowing and planting timings tailored to your location, give our Garden Planner a try. It uses data from your nearest weather station to calculate the best times for you to plant, and our 7 day trial is completely free.

Plants Related to this Article

Carrot Grow Guide

Zucchini Grow Guide

Cucumber Grow Guide