We start peppers early because these heat-loving plants take a long time to mature, and in a temperate climate we want to get a head start. Since peppers are tender to frosts and require a lot of heat, we have the option to either start them indoors, in trays or buy large seedlings in late spring, when it’s time to transplant them in the ground.
If you’re starting peppers for the first time, you’re probably wondering when it’s time to move them to a larger pot, and why you should do that at all.
Pepper seedlings need to be moved from module trays to bigger pots when their first true leaves (the second set of leaves) have fully developed, and when the third set of leaves are about to emerge. At this point, peppers need more space for their roots and they need to be fed regularly.
Peppers are generally started about 8 to 10 weeks before the last frost, and they go out in the ground a couple of weeks after the last frost, so they’re not in danger of getting damaged by the cold. So we are looking at about 12 weeks of keeping pepper seedlings indoors, from germination to transplanting outside.
With experience, you’ll figure out the best time to sow peppers, so that they don’t spend more time indoors than they absolutely have to, but until then, you need to know the basics about timing and care:
1. The second true leaves are a good indicator for potting on
You may have read from various sources that you should move your pepper seedlings to bigger pots at 4 weeks old, or even 2 weeks old. However, you can’t really rely on those numbers because peppers are often finicky and don’t develop at the same rate.
Not all peppers will germinate at the same time – for some, it might take 5-7 days, for others, it might take as long as 4 weeks, so don’t lose hope. A lot of factors contribute to the pepper seedlings’ growth and wellbeing: heat, moisture, seed quality, seed age (older seeds take a long time to germinate), seed variety, and light.
Moving peppers to a new pot will probably be a gradual process, as seedlings start to emerge. So don’t get stuck on a date or a period of time, just watch for when the first true leaves have fully grown and the second true leaves are about to emerge. Remember that the first leaves on pepper seedlings aren’t “true” leaves.
2. The main reason to transplant pepper seedlings
So why not just plant peppers later in the season, directly in trays, and not worry about this entire potting-on hassle? Well, as I mentioned, peppers grow slowly, and if your peppers are too small in the summertime, they’ll catch up to some degree, but you’ll probably get fruits in late autumn instead of summer. Unless you’re in a tropical climate, starting them indoors is the way to go.
The second question is – why not start them directly in bigger pots if we know we’ll have to move them anyway? You could definitely do that if you don’t have a lot of peppers to grow, but starting them in module trays will save a lot of space and “real estate” under the grow lights in February and March when you’re going to need that space to grow other seedlings as well.
As space frees up underneath your lights or in the greenhouse, your newly homed pepper seedlings will have more room to keep growing.
Aside from practicality, we need to move peppers to bigger pots so that they don’t become rootbound, which would stunt their growth and delay your harvest.
3. What pots to choose for your pepper seedlings
I start growing my peppers in these 72 cell seedling trays, and they typically stay in there for a few weeks. I amend my starting mix with vermicompost, this way I’m confident that they’ll have enough nutrients even if they end up spending more time in the modules than planned.
When I see the true leaves fully grown and the second set of true leaves about to emerge, it’s time to pot on:
- Step 1. I choose a 3-inch pot, make sure it’s clean, label it, and fill it with soil halfway.
- Step 2. I separate my pepper seedlings if I have more of them inside a module (and I usually have 3-4 of them).
- Step 3. I fill the 3-inch pot halfway with moist potting mix and make a hole.
- Step 4. I carefully place the pepper seedling root in the hole and cover the remaining root and the stem close to the pepper’s first leaves.
When choosing the right-sized pot to transplant your pepper seedlings, you need to have two goals: the pot has to be large enough so that the peppers have room to develop for another 6 to 8 weeks (approximately), and it has to be small enough so that the peppers’ roots hold the soil when it’s time to transplant them into the ground.
I found 2.5 inch plastic nursery pots with generous drainage to be perfect for this purpose. You can pick from a variety of shapes and sizes. After your peppers are transplanted into these cups, keep the cups inside flat trays and bottom-water them.
4. Will I need to re-pot again?
Probably not. If you’ve started your seeds at the right time, and not too soon, they won’t need to be moved a third time until they get transplanted outside.
However, if you want to grow certain varieties inside containers, you can definitely move them to the final container when the weather allows it.
For growing peppers to maturity inside containers, you’ll need a pot that’s at least 10-12 inches wide and deep, although hot peppers are more forgiving and require less space.
If you’re growing your peppers on a balcony or on a patio inside pots, they still need support, otherwise, their branches can snap from the weight of the fruits. Use a bamboo cane and tie up peppers regularly.
What else you need to know:
When potting on pepper seedlings, give them access to nutrients
You’ve probably heard of the notion of “feeding” your seedlings. You can start using liquid fertilizer right around the time you are moving them to a new pot, as they will need more nutrients to withstand transplant shock and thrive.
You can either buy your liquid fertilizer pre-made (liquid fish & seaweed fertilizer or some hydroponic ones are really good for this purpose) or make your own at home. Look for recipes for compost tea, comfrey, poultry manure, and many others.
You can skip this step if your potting mix is already rich in nutrition. I like to mix my potting soil with plenty of compost, which feeds peppers as they grow. If your pepper seedlings show signs of yellowing, it’s definitely time to feed them.
Hot peppers develop slower
You can probably get away with moving hot peppers to larger pots, as they develop slower and grow smaller than sweet peppers. They still have the same needs, they just won’t be needing the same amount of space in your garden.
Sweet peppers mature and produce within 60 to 90 days, while some hot pepper varieties can take as long as 150 days. So if your hot peppers look stunted and like they’re growing too slowly, don’t worry, it’s perfectly normal. When that harvest comes, you’ll be glad you waited.
Figure out how many peppers you actually need
We talked about moving peppers from trays to 3-inch cups, but we didn’t mention thinning in this process, we only talked about separating the seedlings. That’s because I don’t sow that many peppers in the first place, and the ones that I don’t end up planting outside, I give away.
But there’s a possibility that you’ve ended up with way more seedlings than you actually need. In this case, it’s best to thin them before transplanting them. Take a pair of fine scissors and snip the unwanted pepper seedlings at the base, only leaving the strongest one in each module.
If you’re confused about how many peppers you want to plant out in your garden, you can plan for this ahead of time. Go to your garden, measure the length and width of the bed you’re planning on filling with peppers.
Your peppers will need to be about 18 to 24 inches apart in all directions – I’d go with 18 inches, as leaving too much room in between them is a waste of space. Divide your bed’s length and width, and you’ll get your number of rows, and how many peppers to plant on each row.
Peppers are super-productive, so you don’t need that many of them either. 3 to 4 plants are enough to feed one person all summer long. If you plan on freezing or canning them, selling or giving them out to friends, the sky is the limit to the amount of peppers you could grow.
In short, once your pepper seeds have germinated, give them heat, water, nutrients, light, and space, and you can’t really go wrong with them. Happy gardening!