When to Repot Chilli Seedlings

Knowing when to repot chilli seedlings is not an exact science. I like to repot the chilli seedlings when they have developed their first true set of leaves.

What are “true leaves” and when do they appear?

You should not repot chilli seedlings until their first true set of leaves appear. When a seedling sprouts the first pair of leaves you tend to see will be long and thin. These are called ‘seed leaves’ or cotyledons. These are temporary and serve to provide energy to the plant as it emerges. The eventually die and fall of the plant.

In the photo below you can just start to see the seed leaves clearly and the second pair of leaves emerging from the main growing stem. This ‘second’ set will be the first true leaves. Once they are as long as the seed leave you will notice they are a different shape, typically more rounded.

My favourite method of planting chilli seedlings is to use module trays. They are efficient with space, look tidy and are easy to use. Potting on the seedlings from tray is also much easier once they reach the appropriate size. Seedlings can easily be removed from trays by pushing the compost rootballs from underneath, which minimises any risk of damaging the roots.

I have spent quite a few years experimenting to find the best best potting mix for chilli plants. Mine is a mix of compost, vermiculite and perlite. However don’t get too hung up on it – regular compaost will do just fine so long as your are mindful not to over/under water your plants.

What if my seedlings are leggy?

I raised the chilli seedlings pictured below on a south facing window sill. I planted the seed on the 24th February – germination took approximately 2 weeks.  Because I wasn’t using any artificial lights or growing these in a greenhouse the seedlings became a little leggy (tall and thin).

This isn’t a big issue as when potting them on I like to pot them a little bit deeper in the soil. The photo below was taken roughly 1 month after sowing the seeds.

At the above stage I will typically pot the seedlings on in to pots about 3″ (7-8cm) in diameter. By using module trays you can simply apply some pressure under the module and pop out the seedling along with the whole root ball – ready for transplanting to the next pot. Next simply fill the remainder of the pot with some fresh compost.

Should I water chilli seedlings after repotting?

Yes. Water them immediately after potting seedlings on. This will to ensure the fresh compost gets in good contact with the seedlings roots. Do not over water them and be sure to let the compost dry out over the following days before watering again.

Young seedlings have very delicate roots which can easily become rotten if exposed to too much water. It is always best to lean towards under than over watering chilli plants.

Knowing when to repot chilli seedlings is only half the battle. For the best success you need to provide them with sufficient light and heat. If your seedlings are leggy like the ones in the photo above it is a sure sign that the plants need some more light. In the case of the above plants, I moved them out to the greenhouse after potting them on to ensure they got a lot more light. If you plant to do the same check out our guide to growing chillies in a greenhouse.

The Aji Lemon plant above appeared in the first photo above, approximately two months after being pricked out. I initially potted it into a 3″ pot before moving it up to its current 5″ pot.

Since I moved the plant to the greenhouse it has become more bushy. You can see more lateral shoots coming out between the main stem and the leave nodes. This is always a good sign the plant has enough light.

FAQs

When should I repot chilli seedlings?
You should repot seedlings when they have developed their first true set of leaves — typically 2-4 weeks after germination (depending on conditions).

What size pot should I repot chilli seedlings into?
Start with a 3 inch (7-8cm) pot, then move up to a 5 inch (12cm) pot once the roots fill that, before a final move to a 1-3 litre pot for the growing season. Only repot when you can see white roots through the drainage holes in the bottom of the pot.

Can you repot chilli seedlings too early?
Yes — repotting before the first true leaves have appeared or the roots are not developed enough can stress the seedling, stunt growth and risk root rot. Wait until the seedling looks sturdy, the true leaves are visible and roots are emerging from the drainage holes.

Why are my chilli seedlings leggy after repotting?
Leggy seedlings are a sign of insufficient light. When repotting leggy seedlings, pot them slightly deeper than they were sitting before to give the stem more support, then move them to a brighter position.

Should I water chilli seedlings after repotting?
Yes — water them in immediately after repotting to ensure the fresh compost makes good contact with the roots. Don’t overwater in the following days; allow the compost to partially dry out between waterings.

When to transplant chilli seedlings outside?
Only after the last frost date in your area — in the UK this is typically late May to early June. Harden them off first by placing them outside during the day for a week before leaving them out permanently.

Be sure to read our full guide to growing chillies to make sure your seedlings grow into strong productive plants.