Starting Hot Pepper Seeds

Sowing is the act of putting your seeds in the dirt. It’s an exciting first step. It’s also a risky one since making mistakes at this stage could mess up your entire garden for the season! No worries. We’re going to take things step by step. Some factors to consider are your geographical location and how many plants you intend to grow. Let’s get started learning how to plant hot pepper seeds!

When to Start Hot Pepper Seeds Indoors

Peppers plants are actually perennials; They will live for many years – as long as the temps stay above freezing. For those that don’t live in tropical climates, we only get around 5 months or so to grow our peppers before the frost comes and they die. The way we lengthen our growing season is to grow our peppers inside about 2 months before we transplant them outside.

So, when do we plant outside? This depends on where you live. The golden rule is to wait until the outside temps are consistently above 55 degrees. For me, on Long Island, NY It’s usually right after Mother’s Day. Consult the Farmer’s Almanac or look at previous trends in weather to get an idea of when to plant outside. And then start planting your seeds indoors 2 months before that.

On Long Island, NY I sow my seeds indoors on March 15 and transplant outside around May 15.

Growing your hot pepper plants inside effectively lengthens your growing season. But don’t start them too early! The goal is to transplant them outside when the roots have reached the capacity of the pot they’re in. It’s all about timing. In my experience, 2 months inside is the optimal amount of time. Read more in the section below about the hazards of growing your plants inside for too long.

How Big Should My Hot Pepper Plants Get?

Take a look at the Bonnie plants usually offered at the Home Depot/Lowes big box stores around April/May. That is your benchmark. For me, the picture below is an ideal example of the size you want your plants to be when you bring them outside:

ghost pepper plant
a healthy looking ghost pepper plant, exactly 2 months old (from sow)
Why not start earlier?

If you’re thinking “Why not start 3 or 4 months earlier?” you’re not alone. Last season I started 3 months earlier thinking that I could get a bigger head start. My plants did not do well. My grow tent got extremely overcrowded which made watering very difficult and reduced airflow, harboring disease. Many of the plants also did not transition well after transplanting outside.

If you want to grow inside for longer periods of time you will need careful planning. First off, you will likely need to repot your plants several times to prevent them from becoming “root-bound”. When the roots grow beyond the capacity of their pot they get “bound” reducing their chances of transitioning outside. They simply cannot break out of the mold of their root ball and end up severely stunted and never reaching their max height, which reduces harvest yields big time.

You also need room, and lots of it. Your plants will get BIG and you’ll need to spread them out to allow for adequate airflow. Which also means more lights to cover the increased growing area. And watering (or determining if they need water) will be much more difficult due to the larger leaves.

I would also suggest that you monitor nutrients and PH with a lot more scrutiny. You won’t find much about PH in this guide and that’s simply because it’s usually outside the realm of what most people want to be bothered with. And also because it’s really not necessary for plants being fed tap water for only 2 months. Once they go outside they will be introduced to rain water and will generally do well in the soil. Unless your soil is crap, most people don’t worry about proper PH for their hot pepper plants.

In case you’re curious, pepper plants prefer a soil PH of between 6.0-6.8. Outside this range the plants will not be able to absorb the nutrients they need and will start to become sickly. This is called nutrient lock. On Long Island, my tap water is around 8 but again, not a big deal if they are only living on it for a couple months…

Double-Cup Method vs Seed Starting Trays

Two popular growing methods when starting hot pepper seeds are the Double-cup, and seed starting trays. Choosing between the two depends on how many plants you intend to grow.

double cup and pots
Double cup method (left) and pots (right)

The Double Cup Method

double cup roots
double-cup roots

The double-cup caters towards smaller gardens (18 plants and under) and is an economical way of growing just using plastic Solo cups. I have experienced terrific results using this method.

Pros: It’s less expensive & you can keep the plants in the cups the entire time while they’re indoors – no need to repot.
Cons: Watering can be a bit of a pain since you’ll need to check and water each plant individually. They can also be more difficult to transport.

Seed Starting Trays & Pots

seeds in dirt
seeds in a seed starting tray

I recommend trays for larger gardens (18+ plants). You’ll start with a seedling tray (pictured), and then repot to a larger 3.5″ pots soon after the seeds germinate. 18 of these pots fit nicely inside a “1020” tray.

Pros: You can fit more plants per sq. ft, saves you a lot of time when it comes to watering, and it’s much easier to transport trays.
Cons: It’s more work since you’ll need to transplant your seedlings, and you’ll need to purchase pots and trays.

page updated 3/16/22