I'm looking for some advice on growing sweetcorn in pots, especially since sowing directly isn't practical for me in the UK due to our short summers and cool soil temperatures until around June. I've been pre-germinating my sweetcorn seeds on damp kitchen paper and then potting them up once they have roots. However, I end up losing quite a few plants when they're about an inch tall, as their stems rot off right at the seed, leaving the roots intact. This year has been particularly bad, forcing me to resow multiple times. I've noticed that friends who grow maize seem to have healthier seedlings in small pots despite heavy watering. Is the issue related to the sweetcorn's seed structure, or is there a better way to prevent rotting?
3 Answers
Instead of the paper towel method, start your sweetcorn directly in soil cups or pots, like using coir or peat. It’s important to avoid root binding—sweetcorn doesn't like being moved around too much. If you're growing in pots, try to start them in the final pots you'll use for harvest. Also, look for sweet heirloom varieties; they tend to thrive more and could result in healthier plants.
It sounds like your sweetcorn might not be thriving due to cooler conditions. Try placing a seedling heat mat under your pots to keep them warm. Additionally, consider your light setup; even though your conservatory gets warm, the nighttime temperatures might be dropping too low for sweetcorn. More light might help too—natural light is great, but if you're seeing quick rot, you may need to supplement with some grow lights.
That's a good point about the heat! I grow them in my conservatory, which warms up nicely during the day but cools at night. I didn’t think light would be an issue, but I’ll look into it. My tomatoes and peppers seem to handle it just fine, but sweetcorn might have different needs.
You might find this video helpful: it covers starting seeds in pots and gives tips on transplanting. Remember, with corn, planting in a rectangle helps with pollination, so you might want to consider spacing them out accordingly. Here’s the link: https://youtu.be/WNUNq4QJ-CM?si=X0JpfDP1z0nPtosh
I go for the paper towel method mainly because it saves space and helps me spot bad seeds early. But I hear you on the root binding issue; I really want to avoid that. I’ll consider looking into some heirloom varieties too!