Top Crops to Sow in March

24 February 2024, written by Benedict Vanheems

Sound the trumpets - beat the drums - Spring has sprung! This is the start of the gardener’s busiest period, when managing sowings, seedlings, and young plants becomes a bit of a juggling act. The growing season starts here!

Terrific Tomatoes

And what better way to start than with the one crop that sums up summer perfectly – why, tomatoes of course!

The tomato encapsulates the bounty of those warmer months. Richly aromatic, sweet and juicy – there’s no beating it for flavor, made all the more intense if you grow it yourself! There’s a tomato variety to suit every requirements, from sweet cherries for adding to salads to plum or paste tomatoes to turn into sauces.

If your tomatoes have suffered from blight in the past, it’s worth looking out for resistant varieties that make growing outdoors much less risky. No tomato is completely, 100 per cent resistant to blight, but there are some that do show good tolerance to this fungal disease, so if you’re growing them outside where they’ll be exposed to spores carried on the wind, you might want to try a blight resistant variety.

Top Blight Resistant Tomatoes

Burlesque
Cocktail Crush
Consuelo F1
Crimson Cherry
Crimson Crush
Lizzano
Losetto
Mountain Magic

Sowing tomatoes is very straightforward. Pass an all-purpose potting mix through a sieve to remove any woody bits, then firm the mix down into a pot. Space the seeds across the surface, as far apart as possible from each other to make the most of the surface area, then just cover them with a touch more mix.

Do not forget to label! If you’re growing just one variety of each vegetable and you’re familiar with what the seedlings look like, you can get away without labeling. But when you’re sowing a few varieties of the same crop, it’s oh-so-easy to get mixed up. I say this from bitter experience!

Water your seeds then pop them into a humidity dome, which will trap moisture and keep your seeds nice and cozy. Covering them with plastic works in the same way.

Tomatoes need warmth to germinate, so a heat mat is useful and will speed up germination. They should sprout within a week, or two at most. If you don’t have a heat mat, a sunny, warm windowsill will work just fine too.

Once the seedlings appear, transfer them to their own individual pots. Now that light levels are much better outdoors, you can move your tomato seedlings out into a greenhouse or cold frame during the day, on milder days when temperatures in there are at least 50ºF (10ºC) to make the most of the extra light. If you’re using grow lights, this will also save on running costs.

Leeks in a flowerbed — Leeks make a real statement when grown in a flowerbed!

Plan Now for Veggie Garden Staples

No one wants to look forward to next winter when we’re only just leaving this one, but forward planning is a must! Knowing what to sow when can be a bit of a logistical conundrum, but I find the Garden Planner invaluable for this because it works out exactly what needs sowing when, based on data from my local weather station. Very handy! Click here to try it – for free – for yourself.

In many areas it’s now time to sow two vegetable garden staples – leeks and parsnips – which will form the backbone to next winter’s harvests.

Leeks

For some reason my dog Rosie loves leeks and rolls about in them, flattening them to pieces. I wondered why she sometimes had oniony breath! But leeks as well as other alliums like onions and garlic are not good for dogs, so I need to think of a way to fence them off from her if I’m to grow them again. For now, I’m going to sow them in the greenhouse to keep them safely out of Rosie’s reach!

Traditionally leeks are sown into either a pot or directly in the ground, and then when they’re about pencil size they can be lifted up and planted individually. It’s a very satisfying process – you make a hole, pop in the leek, then simply fill the holes with water and walk away. The leeks then grow on to produce lovely long, white stems that are naturally blanched by staying in the dark, below the soil surface.

Alternatively, multi-sow pinches of about six seeds into pots or plugs. Cover them over and water them. Expect three to six seedlings per plug to sprout. Grow them on under cover until late spring then plant them outside as little clusters, no thinning required. You’ll then have clusters of leeks to pull up as needed from autumn onwards.

I sometimes like to pot the clusters of leeks on, them plant them as a succession crop after my early potatoes are lifted, which means you get two crops out of the same space by staggering them. If you don’t feel you can devote much space to leeks, how about just planting them in among your flowers? With their thrusting-skywards glaucous leaves, they’re very attractive in their own right and add a real touch of designer glam to any border. What do you reckon?

Sowing parnip seeds — Parsnip seeds take a long time to germinate

Parsnips

I used to be nervous about growing parsnips because they’re said to be tricky customers to start off but, although they take their time to rise and shine – up to four weeks – they are actually very reliable germinators so long as the soil is warm enough.

Parsnips need reasonably fertile soil. Mark out a couple of rows about a foot (30cm) apart, and sow a seed about every inch (2cm) or so. Cover them back over and, given they take a long time to come through, it’s essential to mark your rows so you know where to expect them to pop up. A stick at each end of the row is sufficient. Also make sure to add them to your garden plan so you know where they’ll be. Once the seedlings appear, thin them in stages until the plants that are left are around six inches (15cm) apart.

A neat trick to get more food from the same space is to sow a row of radishes between your parsnips at the same time. By the time the parsnips come up the radishes will be well ahead, and they’ll be harvested long before the parsnips need the extra space. Space the radish seeds about an inch apart, cover with soil, and and water the row. The radishes should be up within a week and shouldn’t need thinning.

Parsnips are royalty among root vegetables (got to love a parsnip and coriander soup or parsnip fries!) and they are generally trouble-free to grow. Do be sure to use fresh seed though, because they are not long-lived.

Collards can be used like a cut-and-come-again cabbage

Eat Your Greens

I love my greens, and it’s time for the first leafy green sowing of the year: collard greens, which are a non-hearting type of cabbage. I’m growing collards this year for the simple reason that last year’s hearting cabbages were interwoven with slugs – they loved it in the folds of the leaves, tucked away and hidden from predators. With their more open habit, I’m optimistic that the collards will make a less cozy home for those slugs!

Another benefit is that collards can be harvested cut-and-come-again style, so I can just twist off leaves as needed, leaving the plant to grow more leaves. I like this because sometimes a great big ol’ head of cabbage can be a bit much all at once!

To save garden space while they’re still young, sow seeds into a pot then, once they have popped up, carefully transfer the seedlings into their own plugs. Grow them on before planting them in a dedicated bed of soil enriched with garden compost. Space them around 18 inches (45cm) apart in both directions.

Chitting potatoes — Chit your potatoes to give them a head start before planting

Start Off Potatoes

This is a great month for planting potatoes if you can offer them protection from late frosts. Our Growing Potatoes Masterclass covers planting in containers as well as the crucial difference between determinate and indeterminate potatoes, and how to use that difference to your advantage. Well worth a watch!

Chit, or pre-sprout, your potatoes to get them off to a flying start, then plant the tubers when they have short, stubby shoots later this month.

If you haven’t bought any seed potatoes yet, get on and do so pronto, before stocks run low!

Poached Egg Plant, Sunny Side Up!

What better way to celebrate the start of spring than with the cheeriest, happiest flower I can think of: poached egg plant!

Poached egg plants readily self-seed once they get established. They’re great as a living mulch beneath taller plants like broccoli and beans, and they often stay green and protect the soil right through winter in milder areas. They are fantastic little flowers!

You can sow poached egg plant directly into the soil. Sowing directly like this, in the spring sunshine, can’t help but instill a real sense of optimism. Just wonderful! Scrape back any mulch that hasn’t rotted down and then fork over the soil to fluff it up a bit, ready to receive the seeds. Take a pinch of seeds and scatter them where you want them to grow. Rake them in and tamp down the soil with the back of the rake.

Poached egg plant is mecca for insects – and I’m talking the really good ones! I promise you that once they start to bloom, you’ll have far more beneficial bugs knocking about to pollinate your crops and devour your pests. Lovely stuff! They won’t need much more attention other than perhaps watering in dry weather while they get established, and if the seedlings come up a bit crowded just thin them out.