The time had come for me to sow a big batch of seeds the other day – all different, so each required its own treatment. A happy couple of hours spent in the greenhouse alongside the tones of Graham Norton left me feeling like I’d just performed a sowing demonstration in the absence of an audience, so maybe we could re-live that morning? Our veg seeds are only going to thrive if we give them a good launch from the packet – here’s how I try to do that.
Important considerations here are light and heat. I’m incredibly lucky – my parents have ample spare greenhouse space (they’re retired market gardeners). It’s lit from all sides, and contains a heated commercial propagator. If you can’t get seeds to germinate here, you’re really doing something wrong.
Windowsills are tricky. Run a reflective strip of aluminium foil or white glossy paper behind your seeds to limit leggy seedlings, and get plants outside as soon as you can (if light levels are really low, then buying plug plants later in the season may be better – if more costly – than sowing now). Artificial lighting is an investment for the serious propagator. Heated propagators are good, but you can buy heat mats instead (these are very handy as you can roll them up when not in use for compact storage, whereas my heated propagator lurks at the back of the shed for nine months of the year).
I’m old school when it comes to seed compost. I use peat-reduced or peat-free formulations for potting up and so on, but for seed sowing, I don’t. This is just my experience – perhaps you can help me here with reports of good results from peat-free seed composts? Whichever your preferred compost, break up any lumps in it (this leads me to stand in the potting bench, bashing like fury with the back of my garden fork) before filling your pots.
Your choice of sowing container comes down mainly to the veg you’re sowing (for ease, refer to the example list below). Fill your container by lightly dropping the fluffed-up compost into the vessel. Leave it proud by 2cm or so, then gently rub across with the palm of your hand to level it, then scrape off any excess – you can use a pot tamper if you prefer not to end up with filthy hands. (Don’t use this method with paper pots as they’ll crumple and collapse. Also, ensure paper pots are crammed cheek by jowl into a deep tray before watering them, as the moisture demolishes their rigidity).
Seed trays: Ornamentals (for pricking out later)
Small modules: Lettuces, brassicas, beetroot, celeriac
Root trainers: Peas, beans, sweetcorn
Pots: Squashes, globe artichokes & broad beans (individually), tomatoes and capsicums (to prick out into pots later)
You want to get enough moisture into the compost before sowing so that there’s no need for additional irrigation before seedlings emerge. I soak compost intended for large-seeded peas and beans, and give lesser amounts to pots that will contain fine-seeded celery and lettuce. Allow the compost to drain, ideally in the warmth of your propagation area.
The larger the seed, the deeper you sow (only very fine seeds, such as antirrhinums and begonias, should be sown on the surface). Watered compost is far easier to make a drill or hole in than dry. A pencil makes a very good dibber for large-seeded lupins and peas. A retired bread knife or ruler is excellent for making shallow drills 1cm deep, for brassicas, salad leaves, etc. Sow as thinly as the seed packet states – we’ve used a surplus 15cm length of aluminium greenhouse frame to help us with small seeds for years. It creates a right angle: tip your packet into this (or whatever right angle you can find) and use a pencil to gently flick the seeds off the end, into your hole or drill.
It’s important to firm over the hole or drill with compost once sown. Re-use your dibber, bread knife or other improvised item to gently ‘squash’ the hole or drill back together, then pat down with your fingers. I finish off the sowing with a topping of as much vermiculite as I see fit (generally for medium-sized seeds, rather than large or tiny ones). Give the seeds a final light water to settle the compost, and pop in your propagator. Job done.
• Lucy Halsall is the editor of Grow Your Own magazine, which contains a wealth of information about growing your own vegetables. There are even more resources on the website, including the new growing guides section.