This week’s tutorial is all about seeds and sowing: the equipment I use; what to sow when; planning how much to sow of each; successional sowing; and what to do with your plants once they have germinated. There is a worksheet attached, as word (to fill in at the computer) and pdf (to print off instead).
One of the tricky things about growing from seed is that you need to sow your seeds when it’s still too dark and too cold for them to grow outside. If you wait until after the last frost date – mid-May, up here – then you’re pretty limited in what you can still sow as many plants need a longer growing season than that. But if you start sowing your seeds in Feb and April it’s too cold for them to go out, and you’ll need a polytunnel, greenhouse or conservatory for them. Or windowsills, but they’ll quickly take over, and you run the risk of them getting too big too quickly.
I sow pretty much all my seeds in the house, into big multi-cell trays. I do this for two reasons: 1. it’s much easier to keep track of how much I’m sowing of each, and it means I can sow things when it is far too cold outside to sow straight in the ground; 2. I can control the growing conditions and keep an eye on the plants. It also means I can do my sowing sitting down, which is a big bonus for someone who gets dizzy easily, and for whom standing is hard work. I sow things at the kitchen table, which is covered with a stapled-on pvc tablecloth that we replace whenever it looks too tatty.
I mostly use these trays, in the 84-cell variety. The cells are big enough that the plants can stay in there from sowing to planting out, and while they’re a tad bigger than A3 they can just about fit on a windowsill if you don’t have a polytunnel. Charles Dowding recently designed a version of these, too – they’re smaller so use less compost, but I don’t know if they plants will need to be potted on before planting them out. But I think these would fit very nicely on a windowsill. Of the 84-cell ones, 6 fill a pallet table nicely.
You can use any and all plastic containers to start your seeds. Yoghurt pots, cream pots and grape punnets are particularly popular, but cut-off milk cartons and tetra paks work really well, too. Just be sure to add some holes in the bottom for drainage. A see-through plastic bag (such as a freezer bag, for example) creates a miniature growhouse for your pots, and bubble wrap is really useful, too.
As for compost, I’ve tried out loads but am really enjoying using the Dalefoot Veg and Salads. It’s a bit pricier but retains moisture really well, and it’s organic and peat-free. There have been problems with compost these past few years because traces of aminopyralid, and as far as I know there haven’t been any issues with Dalefoot. There is a bit of info about this towards the end of this post.
Seeds and plug plants
There are two ways of growing your own: grow from seed or buy in young ‘plug’ plants (of which our own plants are an example). Some people think that buying in plants isn’t ‘growing your own’ – but I think that’s nonsense! There’s a lot of privilege in having the time, space and money to grow things from seed, and whatever works for you, works for you. That said, I very much enjoy growing things from seed, and I’d recommend having a go if you can!
I use a variety of seeds – saved ones, commercial/F1 ones, heritage ones. Because of the Free Food Garden and the free plants folks have been kind enough to send us lots of seeds, but if you’re starting from scratch things can seem really overwhelming.
I think that if you’re starting out you’re best to figure out what works for you before spending a ton of money on it, so in the past I’ve always suggested folks stock up on Lidl seeds to see what works for them. With Covid that might be trickier (we haven’t been to a supermarket since last March), but if this is something you’re able to do it might worth considering. I know nothing of these seeds except they’re cheap and they germinate/grow well – but I know nothing about who produces them. But then I don’t know that for a lot of companies and seed sovereignty is a massive issue – I’d recommend checking out Sara Venn’s posts on this subject. With that in mind, I’ll share a small list of where I have bought seeds over the past year: Sow Seeds, Simply Seed, Real Seeds, organic gardening, Heritage Seed Library, Vital Seeds. I also subscribe to Grow Your Own magazine and use the seeds from it.
What to sow when
Knowing when to sow things can be really tricky, and while general guides are useful it’s best to keep detailed notes so that you build up your own version over time. Charles Dowding’s sowing schedule is a good basis if you’re further south, and you can use mine if you’re further north. Mine is an excel sheet and tells you what I sow when, and where I keep those plants until they are ready to be planted out. I would suggest that you copy the sheet and keep notes on what you actually do – when you actually sow things, how much you sow, how much germinates/grows, and how well it does. Over time you’ll be able to amend this schedule to make it your own, and to move sowing dates around so that they work for your climate, and for how you raise your plants.
My sowing schedule covers successive sowing – that is, sowing repeatedly throughout the season so that there is food pretty much all year round. The schedule indicates the expected harvest season by different shades of colour. This is intended for both outdoor use and inside the polytunnel – we’re lucky to be able to grow a lot of things outside over winter, but this depends on your climate and how much ice, snow and wind you’re likely to get (and whether or not your space floods). But it’s worth experimenting with, and any fresh harvests are so very welcome in winter and early spring. Because we’re so far north we have to sow our autumn and winter things quite a bit earlier than folks elsewhere in the country, and Dowding’s Winter Veg book is a great resource to get you thinking about this.
How much to sow
That’s a really tricky one – it requires a bit of thinking and planning. Here are a few things to keep in mind:
- are you going to sow once or sow successively (or buy plans once or throughout the season)? If you sow/plant once you need to find room for *that* many plants, but if you sow/plant successively you need to think in ‘layers’ and not just find room for things, but also think about when space will become available again
- are you going to plant your things in neat rows with lots of spacing, like the seed packets say, or closer together with smaller things interplanted? For example, quick-growing crops like radishes and lettuce can be planted between slow-growing ones like broccoli so use up the space. They’ll be harvested before the big crop shades the bed.
- how big are your plants going to get? Much of the bed will they take over, and for how long? A sweetcorn, for example, is really tall, while a squash will sprawl and sprawl and sprawl. The planting guide might be useful here
- are you planning on harvesting your crops in one go or regularly? For example, if you just pick leaves from the outside of lettuces you can keep harvesting for ages, but once you’ve lifted the whole head you’re not going to get any more.
- how much of each thing will you need or want, and how much do you have room for? You may want to grow 10 broccoli but they take up a lot of room.
- what can you buy easily locally, and what is really expensive/difficult/not local to buy? For example, raspberries are expensive in the shop but, in a decent year, just fruit away at home and you’ll be eating them by the pawful. Potatoes are in really good supply and not that expensive, but take over a lot of ground for a long time. Our preference is always to grow leafy/fresh/fun things (kale, lettuce, etc.) rather than potato/onion/carrot if a choice is to be made. We have never managed to grow all the onions and garlic we use in a year, and we’ve grown a lot of them. But we grow all the ‘green leaves’ when we get the timings right, and we eat that stuff for at least two meals a day.
- can you eat more than one part or the plant you’re going to grow? Broccoli leaves are delicious. Carrot tops make great pesto. Beetroot leaves are so good as salad. Can you harvest a small amount of these while the rest of the plant continues to do its thing?
- if you grow from seed, how sure are you of your germination rate – that 1 seed = 1 plant? Plant some extra just to be sure, and keep some back (if you’re sowing in module, rather than sowing straight) so you can fill any holes with more plants.
How to sow
I fill my module trays with compost, firm it down with two fingers, put the seed in, add compost on top, and firm it down again (but less hard this time). This seems to work well for any and all seeds – I don’t bother sowing things at varying depths in the module trays. I pre-sow pretty much all my plants, though there is something to be said for sowing carrots and parsnips straight in the ground – ideally with a bit of sand mixed in. This helps them grow straight, and if you pre-sow them in a module they’ll probably come out wonky. I hate the thought of ‘pricking out’ – of sowing seeds and then thinning out the seedlings – and I’d rather sow in modules than outside.
I tend to sow full rows of things to make labelling easier. This way I only need one label per row – or one label per many rows, or even one tray if I sow lots of the same thing. I use plastic labels and reuse them: I write on them with the Artline Garden marker (which withstands sun and rain really well), and then clean them with a magic eraser. You can also make plant labels from milk bottles or other plastics. I don’t use wooden labels because they tend to rot on me and I can’t wipe off the writing. I note a number of things on my labels:
- Type of veg (Beetroot)
- Variety (Boltardy)
- Sowing date (30/2)
- Amount sowed (7; or 7×3 if I multisow them)
This helps me remember not just what I’ve sowed but also gives me an idea of how well things have germinated (and how long they’ve taken to do it), and whether or not things are come along well.
I multisow some things. This means sowing more than one seed in a module, and growing the plants on together without separating them. I tend to sow in clumps of 3-5, and I do it for things like beetroot, onion, spring onion, turnip, radish, leek – basically all ‘root’ things except carrots and parsnips. I also multisow some lettuces and rockets if I’m looking to create dense patches of ‘cut and come again’ plants, rather than growing big heads of individual things. It usually works really well though this past season our beetroot and radish have been disappointing, so this year I’m going to try sowing them individually. But if you’re short on space or would like to cram in more it’s definitely worth trying!
What happens to my plants after I’ve sowed them depends on what they are. Like the sowing schedule tells you, some I keep indoors but most are moved out to the growhouse. Generally the only things I’ll keep indoors are ‘hot’ plants – chillies, peppers, aubergines and tomatoes (though melon would be in that group, too). By the time I sow squash, pumpkins, courgette and cucumbers it’s warm enough outside that they just live in the growhouse.
For the first few weeks of sowing – until the later parts of April – I keep all freshly sowed trays in the house until the germinate. This is because at the very start your seeds need heat, but not light – that changes after they germinate, and as soon as you see little specks of green poking through it’s all about the light, and that’s when I move my ‘non-hot’ plants out to the polytunnel to grow slowly. From the second half of April, depending on the weather, I’ll move trays outside straight after sowing because the temperature is high enough for things to germinate there.
If you don’t have a growhouse available your best bet is a cold conservatory or an unheated south-facing windowsill. It’s hard to get enough lights to plants early in the season, particularly this far north, so you might want to invest in a set of growlights to help things along. Mine are in a timer, and are on for 12 hours a day from February to late April. They light the ‘hot’ plants that I keep in the house – the plants outside do not have any electric light or additional heat.
A small plastic ‘tomato greenhouse’ might be an idea if you have a sheltered spot for it somewhere – it’d be a great please to keep pots and module trays until things are ready to go in the ground, and then you can use it for tomatoes or chillies etc.