Peppers are temperamental to start. The joy of starting tomatoes is that they just go for it, in most cases you get all seeds you start germinating within a few days – I only put one seed in per cell. Not so with peppers! It’s like pulling teeth.
One problem is seed life, which is unpredictable. In Ashland I felt confident that pepper seed would last for a few years, but here in Lebanon (much more humid), pepper seed may have trouble after only a year or two. I started test for this, in 2016, just to see what different storage life was. I took a couple of packets (Orange Sun from Nichols) and divided them into three batches. In 2020, did a side-by-side germination test:
- Stored in the box with other seeds, not airtight, room temperature: 0 out of 10 germinated
- Stored in canning jar in the fridge: 3 out of 10 germinated
- Stored in canning jar in the chest freezer: 9 out of 10 germinated
I am now storing all my peppers in the freezer! Even fresh seed, though, can take some days to germinate and will not germinate 100%.
Here is my system:
I start peppers right after the tomatoes, between March 15 and March 30. This allows time to start another round for anything that doesn’t germinate. Peppers get planted out as much as a month later than tomatoes.
All pepper seeds are started on shop rags or paper towels. (Watch out for cheap paper towels that dissolve after being damp for a week). This lets you see what has germinated and not have lots of empty cells.
Get the paper towels pretty wet to start with, later they should be damp but not dripping; put the seeds on, put in a label, and fold into quarters. Put a stack of wet paper towels into a small plastic bag and fold over but don’t seal, it should NOT be airtight. Put in a warm place. I usually put mine on top of the grow light over the tomatoes, but be careful it’s not too hot.
Every day, check the seeds for germination – a little white root tip; it also airs the paper towels and prevents too much mildew. I’ve seen germination in a couple of days, but it can take a week or 10 days… or not germinate at all. Re-dampen the paper towels as needed. I remove a seed as soon as I see any root; left to themselves, the root can grow though the paper towel and get damaged on removal.
When you see germination, very gently transfer the germinated seed to a cell tray. I usually use 50-cell trays for this. Use seed-starting mixture (I use potting soil mixed with a lot of perlite and sifted to remove the giant pieces – the key is something that drains well). Plant about 1/4″ deep. Water, label and put on a humidity cover. Set tray on a heat mat; it will need to be kept warm and moist until the seedling has emerged from the soil. I don’t put under grow lights until something has emerged from the soil, but grow lights do add some warmth. Not every seed will make it but usually only 2-3 failures out of a tray of 50.
Once the first seedling is up, it goes under a grow light. I try to leave the humidity cover on until all the seedlings have emerged from the soil, but it doesn’t always work. The grow lights are on 16 hours a day; sometimes 24 hours. While I think plants ought to have light-darkness cycles, they just seem to want more light than the grow lights provide and I haven’t seem problems with 24-hour lighting.
The seedlings will start with two seed leaves, then get their first set of true leaves. If your soil does not have any fertizlizer (seed starting mix might not), then you’ll want to very gently fertilize once there are true leaves. I use a all-purpose granular 7-5-4, a pinch per cell and mix in. Using a liquid fertilizer is easier but be very careful to make it mild – it’s quite easy to burn the little roots. My potting soil already contains nutrients so I wait until the last-germinated have their true leaves and the first-germinated are on their second true leaves.
Once all the plants have a couple of sets of true leaves, I make as much effort to get them into real sunshine as possible, while keeping them warm. Peppers can be permanently stunted by exposure to excess cold. The risk is temperatures under 50 degrees, or possibly under 55 degrees, and I’m not sure how long at this temperature it takes to do damage. You’ll know since in the garden, they stay small and stunted and somewhat twisted. So, as much sun as possible but not at the risk of chills.
Pepper plants get planted out as late as possible, for me that’s usually into June when the ground is warm and the days are long. Even then, I put a 40%-50% black shade cloth over the rows, which keeps the wind off, and helps keep them a bit warmer at night (and also helps against sunburn). This stays on for most of June until the real heat of summer starts. You can’t coddle peppers too much.
Oddly, peppers can handle the chills of late fall much better than tomatoes. We put blue tarps over the plants in late September or October, and the peppers keep ripening, long after all the tomato vines are past.