Shortly after your seedlings have germinated you will need to transplant (or “up pot”) them into larger containers. I prefer the 3.5″ starter pot since you can fit 18 of these into one “1020” tray. The starter pots have holes in them to allow water to drain through and into the 1020 tray below.
There are tons of variations to meet budgets of all sizes. Some people transplant into Solo cups on baking sheets for example. I prefer the 3.5″ pots in 1020 trays since it provides adequate stability when transporting the plants and maximizes space.
Once the majority of your seedlings have sprouted you can turn off the heat mat if you’re using one. They also need light as soon as they sprout so be sure to read the next section on lighting.
When to transplant hot pepper seedlings
It is generally safe to transplant at any stage. When seedlings are very young their main tap root is very short and fragile and can be easily damaged when you try to pull it from the tray cell. Hot pepper plants are very resilient and can tolerate mild root damage, howeve it can stall out the plants growth. If you wait too long to transplant the seedling it is possible that the roots might become tangled within each other and grow out of the bottom of the tray making it difficult to pull which could also increase root damage.
I like to wait until most of my seedlings for a particular plant have sprouted, which is usually within 7-10 days.
Prepare the starter pot
Grab your 3.5″ starter pot or whatever you’re using and fill it up with soil. I like to use FoxFarm’s Ocean Forest or Happy frog soil. I smack the bottom of the pot on my table which helps the soil settle and then fill it up again with soil to the top of the pot. The soil will settle when watered. Use your finger and create a hole in the center of the pot. Make sure to label the pot with the type of pepper! I use these stakes and write on them with black permanent marker.
Removing the seedling from the cell tray
I take two wooden popsile sticks and shave one end down using a knife so that the end is sharp. I slide each of the sticks down each side of the cell (think of eating with chopsticks) and pull out the entire soil ball, roots and all. Sometimes this doesn’t go as planned. The seedling might not come out easily and sometimes the soil falls apart after it leaves the tray. As long as most of the root is intact they plant will survive. You can also experiment by watering the soil right before you try to pull the seedlings (or let the soil dry out).
Put the soil ball (or seedling roots) into the hole in your starter pot and cover it with soil. Pack down the soil firmly to ensure it will stay put after watering.
Cells with multiple seedlings can be separated and planted each one into their own pot. Or, you can put the entire root ball with all seedlings into the starter pot. This improves the chances that at least one will survive the transplant. Later I will keep the best looking seedling and clip all the others at the soil level.
Place the pots into the 1020 tray and gently water each pot to the top. It’s important to water gently since the soil is very loose and can easily wash away.