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How To Sow Onions Right Now!

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Onions grown from seed take a long time to reach full maturity; that’s why they make such a good candidate for early sowing.

But if you want to sow them early in the year, what do you do? Here’s how I sow my onion seeds early in the year!

To begin, these are sown indoors with the aid of a grow light.

You can sow in a greenhouse and get okay results, but you will get much better germination indoors, especially in January.

These are the module trays I will be using for my onions.

Module sowing is great because it gives you a lot of different options, and you can sow a whole lot of onions at once.

You can take the whole module and plant it out in the garden and grow it as one big clump of onions, the Charles Dowding method. Or you can split the onions up and plant them individually.

I use coir compost for all of my indoor sowing. There are a couple of reasons for this: one, it is very easy to store indoors in its dried-out brick form, and two, it is sterile, so you don’t need to worry about fungus gnats!

Just a few different varieties of onions to sow this year!

This is why I love growing onions from seed; there are so many different varieties to try, and they are incredibly cheap to boot.

Onion seeds are very small, so they are quite hard to handle.

I just take a few between my fingers and scatter them into a module. I am for 5-8 seeds per module.

I just sow them on the surface before coming back and giving them a gentle nudge under the compost.

I will then add a fine sprinkling of compost on top, just enough to cover the seeds.

Germination indoors is fairly rapid; below are my seeds after around a week.

Different varieties germinate at different speeds. Notice the ones on the right have only just started to germinate but were sown at the same time.

If you notice your seedlings leaning like the ones below, then they aren’t getting enough light.

Mine are below a grow light but they are clearly too far away from it, they are lenaing towards the more powerful grow light that is above my chillis next to these onions.

This is an easy fix I just need to either bring the light closer or stack something under my onions to push them closer to it!

I like to begin hardening my onions off when the worst of the winter weather is behind us. They are tough plants and can be quite happy in a greenhouse in late winter before going into the ground in spring.

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