You Must Sow These in Midwinter

, written by Benedict Vanheems gb flag

Sowing strawberry seeds

It may be cold, but believe it or not, now is a great time to sow some warm-season favuorites and a couple of other surprises…

Sow Early Carrots Under Cover

Early varieties of carrot will patiently sit out cold conditions to germinate in their own time. You don’t need a rich growing medium for carrots, so I reuse old potting mix from last season for my carrot seeds. I just pick through to remove any old crop residues and bits of root first, then sieve it before adding some sand for extra drainage.

Carefully scatter the seeds over your prepared potting mix and then cover them over with a little more of the mix. Growing in containers not only means you can start your carrots off under cover, where it’s a touch warmer than outside, but it also reduces the risk of carrot flies discovering them later on in spring. I also pop an old sheet of glass over the top for a little extra warmth to encourage the seeds to germinate.

Keep the potting mix moist as needed. Harvest your carrots carefully in stages, so that those remaining can continue to grow on and get a little bigger. Trust me, these early carrots will be the sweetest, most prized of all!

Early-sown chillies produce lots of fruits over a long period

Sowing Chillies

I’m starting with chillies, which need a long growing season, especially in cooler climates like mine. By starting now, I’ll already have stocky plants well on their way to producing their first flowers and fruits when conditions improve enough to plant them outside.

Chillies absolutely loathe sitting in soggy soil, so they need a really free-draining potting mix. Most potting mixes, especially peat-based ones, hold onto moisture a little too well, so a peat-free, soil-based potting mix – sieved to remove any bigger lumps – works well. Add about the same volume of coconut fibre (coir), and then, to finish, a couple of handfuls of vermiculite. Vermiculite isn’t essential, but it does help with the overall lightness of the mix.

Space the seeds out across the surface of the potting mix, then cover them over with a little more mix. Gently push it all down so the seeds are in good contact with the mix. And – very important – label your pot with the variety and date.

I have had fairly good success by simply popping a piece of clear plastic over the top of the pots and then germinating them on a warm windowsill. But this year I’ve invested in a new setup that I reckon should speed things along and give superior germination – more on that later.

Eggplant seedling
Eggplant needs a really long growing season, so an early start maximises the chance of a harvest

Start Eggplant Early

I’ve always found getting a harvest of eggplant a little tricky. They need a super-long growing season, and they love a really warm summer too. Sowing very early should increase my chances of a decent harvest by sowing these guys now. It’s also a good idea to go for smaller-fruited varieties in cooler climates, as these may reach a harvestable stage sooner than those producing larger fruits.

Soak the seeds in warm water for a full 24 hours to speed their germination, then sow into a soil-based seed-starting mix.

Humidity dome on a heat mat
A humidity dome on a heat mat helps get warmth-loving crops off to a great start

Using a Heat Mat

It’s far too cold outside right now to germinate either my chillies or eggplant. Both of those sun lovers like it nice and toasty – and when I say ‘toasty’, I really mean it! Aim for a balmy 80ºF (27ºC), though they’ll germinate down to around 70ºF (21ºC). Either way, that’s a little warmer than my house usually gets in winter, so this year I’m going to rev things up a bit with a heat mat.

Heat mats give a gentle heat from the bottom up, and many have a thermostat for consistency. First the seeds need to go into a simple humidity dome, which will trap moisture and a little warmth, and then the whole thing is placed onto the heat mat.

If you don’t have a heat mat or humidity dome, then plastic secured in place with a elastic band works too. Try to keep the pots as warm as possible to germinate – above a fireplace or radiator, perhaps. Remove the plastic once the seedlings come through.

Chili seedlings under grow lights
Grow lights encourage sturdy growth

Getting a Super-Early Start with Grow Lights

One of the biggest challenges at this time of year is getting enough light. In the poor light that’s naturally available at this time of year, the seedlings will grow thin and weak. Once most of your chili and eggplant seedlings have germinated, move them under grow lights to keep them growing strongly.

A basic set of grow lights can help with these very early starts. My growlight setup is fairly ancient, but still does the job. Keep grow lights on for about 12 hours a day.

Leggy seedlings on a windowsill
Early-sown seedlings can get very leggy when grown on a windowsill with insufficient light

If you don’t have grow lights, I’d suggest delaying sowing of these warm-season crops by another month. That way you can grow them on a warm and sunny windowsill once they have germinated when light levels will be a little better. To help reflect more light from the window onto the seedlings, surround them on three sides with white or foil-lined cardboard. This should help prevent seedlings from leaning too severely in one direction. Or, if you have somewhere with good light coming from at least three sides, that should work too, for instance a bay window or sun room.

Remember that the seedlings will get bigger and need potted on into larger containers while it’s still too cold to plant them outdoors, so make sure you have enough space for this.

Sowing strawberry seeds
Tiny strawberry seeds need light to germinate

Sowing Strawberry Seeds

And for dessert…strawberries! The easiest way to start off new strawberries is to buy strawberry plants, or you can propagate runners of existing plants. But you can also grow them from seed too.

Scatter the dust-like seeds over the surface of pre-moistened seed-starting mix. These seeds, like many really tiny seeds, actually need light to help them germinate, so don’t cover them over. Mist them with water, then bring them indoors into the warm to germinate. Ideally, put them in a humidity dome and pop them onto a heat mat.

Once they’re big enough to handle, carefully transfer the seedlings into their own pots. Grow them on in slightly cooler conditions, then gradually acclimatise them to outdoor conditions ready for planting towards the end of spring into a sunny spot.

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