Chilli Sowing Guide
There's a lot of conflicting advice on when to sow chillies, and that's because everybody's setup is different. But this particular guide is going to say January. But with the caveat that it will only really work if you can keep them somewhere warm. Here's why:
Pros of early sowing
- Chillies are slow-growing. In the UK, the season is short. It helps to get a head start
- The seeds germinate far better when warm, so even if you wait till March, a cold snap can ruin germination
- If it doesn't go well, you've got time to try again
- January can be a bit grim, eh? Why not enjoy some seedlings?
Cons of early sowing
- You need to supply some heat to get a decent germination rate
- Light can also be a problem at this time of year
- You spend time and space looking after plants that are growing reeaally sloooowwlly
So with that out of the way, here's what to do.
Choose your medium
You don't need any nutrients at this stage, so that isn't a concern. You want something that's not too coarse, too ensure good contact with the seeds, but you can manage without a specialised seed compost. Many growers now recommend a coarser grain, which may help the seedling shed its seed case as it pushes through. DO go peat free, but beware certain soil-based peat-free seed composts, as they can dry as hard as clay, damaging tender roots and shrugging off water. Coir is okay, but also shrinks irredeemably when dry, and can rot when wet, contributing to 'damping off'.
I'm using a coarsely-seived wood-based compost. If I had it, I might add a bit of vermiculite for water retention, but I generally keep things cheap and simple, and it seems to work.
Plant your seeds
Use either small pots or seed modules. Modules are good, because you can fit more in. Pots are good, because you can remove and replace as necessary, and don't need to pot on so soon. Using a pencil or somesuch, make a divot in the soil so that the seed lies about 5mm below the surface, and then cover it with a sprinkling of compost. Water thoroughly. And don't forget to label!
Heat your seeds
Any heat will help, but a temperature of 28-30°C is ideal. You have options here and the easiest is to stand the pots on a heat mat. Be sure to put a bit of insulation beneath the mat, so that you're heating the soil and not the windowsill. A better option is to create a lidded vessel to go on top, using whatever you can find (old food packaging works well, as pictured). This will improve humidity and prevent the soil from drying out so quickly.
For more space and better control, use a plastic storage box, line it with insulation, and put the heating mat inside. A thermostat is a good precaution, and you'll need some ventilation holes. Your plants will struggle for light once they germinate, so adding grow lights means you can leave them inside until they reach a good size for transplanting.
Finally, you can buy a propagator. These can be anything from £20 - £200; a cheap one, while often under-powered, will still afford you some success. It's worth noting that your plants will stall when they come out into the cold, dim light of a winter windowsill, so look for something with enough room for a bit of growth.
The Next Steps
Depending on your set up, you'll want to move the plants on sooner or later. If it is sooner, wait until the first set of true leaves is fully formed before you transfer them to another pot. If it is later, ensure the plants are not crowding each other out and restricting airflow where they are. And from here on, you're on your own. Or at least until I write a more general chilli guide to take you through the rest of the season. Happy growing!
Problems
Helmet head is the condition whereby the cotyledons (the first pair of 'leaves') are unable to emerge from the seed case, so the seed appears to be stuck on the seedling's head. There are things you can do to lessen the likelihood, but it seems there are always a few that this happens to. Trial and error suggests that keeping the seed moist, and letting the plant do its thing, is effective in 80% of cases. If that doesn't work, try teasing it off with tweezers, or giving it a snip with extra-fine scissors, but save this as a last resort, as the cotyledons are easily damaged, and if too much is lost then the plant will cease to grow (annoyingly, it will usually not die either, leading to weeks of wasted effort in the vain hope of a happy ending).
Damping off is the term used to describe seedlings dying soon after germination. It can be caused by a number of different, mainly fungal pathogens, and once the symptoms are visible in a plant it will be too late to save it. Typically, the first sign is the plant topples over, but this can also be the result of leggy growth due to low light, so don't give up on it until you've ruled that out. Prevention is the best you can hope for, and while it's beyond the scope here to go into detail, good hygiene, using clean water, not overwatering and ensuring good airflow can all help.
Aphids. Where do they come from? Who knows, but in the middle of winter, while all other insects are deep in sleep, up they pop. Somehow, those feeble portly bodies, with their stumbling stilt legs and pathetically aimless flight, find their way into houses and home in on chillies like a precision guided missile. And once there, even in small numbers, they are ridiculously hard to get rid of. Tempting as it may be, avoid chemicals - these can burn young leaves and even kill plants. If the plants are sturdy enough, wash the bugs off under a running tap or with a hose. Rub your fingers along the leaves to squash them, if you like that sort of thing, or pick them off with a paintbrush or a bamboo skewer. You'll think you've got them all, but you won't have, so check again every few days and you should be able to keep things under control.