Starting Pepper Plants Indoors

Seedling starts
Photo by Francesco Gallarotti

Living in a climate with a winter season is enjoyable. You can enjoy some skiing, watch the calming snowfall, maybe pack a snowball and throw it at your friends. However, winter has its drawbacks for gardeners. Cold weather shortens the growing season for outdoor growers. This means that starting pepper plants indoors is necessary.

This article will cover the basics on how to start pepper plants inside at the beginning of the growing season. Maybe you saved some seeds from last year, or you’re growing for the first time. We will focus on peppers, but these guidelines can also apply to many other slower growing plants, like tomatoes, eggplant, and even coleus. Let’s get started!

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When To Start Pepper Plants Indoors

One of the best ways to increase your pepper plant’s yield is to start from seed indoors in late winter. This allows the pepper plants to fully mature by the end of the season, producing maximum ripened peppers. In general, the started plants will need 6-8 weeks indoors before transitioning to a permanent outdoor spot.

Exactly when to start your peppers will vary by region, but a general rule of thumb is to start seeds indoors in mid-late February. Depending on your hardiness zone, you can then move plants outdoors once the risk of frost is gone. In warmer regions, the growing season will be longer, and plants can be started earlier to extend the grow season. In Northern climates, plants are typically started later. With the proper grow light setup, you can start your plants very early to truly maximize the growing season.

For an exact recommended start date, enter your postal code here.

Seed Starter Soil For Peppers

When starting seeds, they require little or no nutrition to germinate. This is because the seeds themselves contain the necessary nutrition to get started. All that a seed needs to begin germination is water and an ideal temperature.

For peppers, the best seed starting soil is something organic with good aeration. This mix found on Amazon will work well, as it contains peat moss and perlite to promote healthy root structure.

Tip: It is important to use new seed starting soil when starting plants indoors to avoid insects and mold. Using leftover seed starter indoors can invite these pests into your home. Beware!

Starting your seeds generally consists of the following steps. Keep in mind that the germination process is usually quick for peppers, and transplanting to larger pots with nutrient-rich soil is next.

Here are the steps to germinating seeds:

  • Choose a starter soil. (We like this one on Amazon)
  • Get some seed starter trays. (Try these on Amazon)
  • Pre-water the soil. This will help with root formation and better water absorption in the future.
  • Fill seed starter trays with soil, compressing lightly.
  • Push a finger into each planter. About 1/4 to 1/2 inch deep is enough, no need to be precise with peppers.
  • Drop 2 seeds into each hole. This will ensure that at least one of the seeds will germinate. If both germinate, you will pluck one of them after the first true leaves form. If you have rare or expensive seeds, just use one seed per container.
  • Cover with soil.
  • Water lightly. We like using a spray bottle, as the seeds just need a bit of water to ensure they are adequately moist.
  • Keep in a dark, warm and moist place. Seeds will take around 3-5 days before sprouting, and during this period they do not need any light. The ideal temperature is around 75F degrees. This will ensure that the seeds germinate as quickly as possible. Mist as necessary, and provide water to the bottom of the trays to keep the soil moist (but not soaking wet).

Tip: If your grow room is cool, try placing a heating pad beneath the seed trays on low heat for a few hours per day. This can help give the seeds a boost.

After your seeds have sprouted, you will need to provide ample light. Without enough light, your plants will become leggy. This may translate to a tall, lanky pepper plant that could under-produce. To give your seed starts the light they need, we highly recommend using a grow light.

Which Grow Light Is Best For Starting Seeds?

Seed germination does not require light. However, once the seeds have sprouted, a grow light should be turned on. This will allow the leaves to photosynthesize and produce their first sets of leaves efficiently.

Can I Use A Sunny Window?

It is common for gardeners to simply place seedlings in a sunny windowsill for light. While this may seem like enough, it is often not. When choosing a window for your seedlings, consider these factors:

  • Is the window south-facing?
  • Are there any obstructions to the sunlight outside? Trees? Fencing?
  • How many hours of sunlight does the window realistically receive?
  • How far north are you? The farther north, the less Winter sunlight you are receiving each day.

The reality of most windowsills in not ideal for young seedling growth. Your seedlings need LOTS of strong light for at least 12 hours per day. While a windowsill will certainly help the plants grow, you will likely find that they become leggy (tall and lanky). This leads to weak plants with lower yields.

What Kind Of Light To Use?

There are an overwhelming number of grow light options available. For the purposes of this article, we will recommend two grow lights. One for a casual grower with 5-10 plants, and one for a larger project, with 10-20+ plants. If you expand your garden, you can always use additional grow lights and be creative with your setup.

  • The Clip-On Grow Light. This light is affordable, and does not require any hanging to position the lights. You can simply clip the light onto a table, plug it in, and bend the lights to the desired height. This particular light on Amazon also has a built in timer to have the light turn on and off at different intervals. This is key while your seedlings are growing!
  • The Hanging Grow Light. A hanging grow light typically requires more setup and space, but also has more power to grow larger plants. A hanging light also allows the plants to grow taller by moving the light up as the plants make progress. A clip on light may have a limit to how high the plants can grow. Hanging lights can also be bought with more wattage and power. Be careful though! Too much light can cause damage to your plants.

This is by no means a comprehensive list of grow lights. One of these will almost certainly be adequate for starting your pepper seeds indoors. If you are looking to do full grown plants, you may want to consider a larger lighting setup, and perhaps even a grow tent.

How Close Should A Grow Light Be To Seedlings?

This is a critical element of starting plants indoors. Once your seedlings sprout, you want your lights to be as close as possible to the plants without causing damage. For a typical grow light with low power, you want the lights positioned about 2-3 inches above your seedlings. Monitor growth and move the lights higher as the plants become taller.

Keep the lights on for 2-3 weeks on a 12-hour-on, 12-hour-off schedule. If the plants appear to have burning or wrinkling, the lights may be too close to the foliage. Keep the lights 2-3 inches above the plants. As the plants grow larger and begin to fill out their foliage, they will outgrow the small seed starting trays. This is when we will transplant the pepper plants into larger pots indoors.

Tip: Be sure you have enough lighting for the number of pepper plants that you have. If you use inadequate lighting, your plants will not reach maximum potential.

Transplanting & Fertilizing

Once your seedlings reach 2-3 inches in height, it is time to transplant to a larger pot. With proper lighting, the plants will develop a strong root system. This will help make transplanting easy.

Steps to transplanting your started plants:

  • Buy 3-inch nursery pots. These are perfect.
  • Buy a standard potting mix. Get something with a full range of nutrients. Miracle-Gro or an organic alternative will work fine.
  • Pre-moisten the potting soil.
  • Fill each pot with soil.
  • Dig out a hole. Make sure it’s large enough to hold your started plant.
  • Place each plant in its own pot. Be careful not to damage the root system while handling the plant. Try to pull the plant out at the base of its stem. Loosening the soil slightly can help. Also, make sure the started plants are watered before transplanting.
  • Cover with soil and compress.
  • Water immediately.

This is almost an identical process to starting the seeds, but instead of putting seeds into the soil, you’re moving your plants. Giving your starts adequate soil and space allows the plants to continue to grow without getting stunted. Without enough room, the plants will stop growing.

Fertilizing

Once you have transplanted your peppers, it is time to start your fertilization regimen. Your potting mix will likely contain some fertilizer, but it is best to supplement with the ideal nutrients regularly.

At this stage, we like to start lightly fertilizing every 2 weeks with a nitrogen-rich fertilizer. Any fertilizer with an even 5-5-5 or 10-10-10 makeup will work well. Don’t water too heavily when fertilizing, and be sure not to over-soak the soil.

Tip: Make sure you have good drainage for your pots. If the water is forced to stay in the soil, it can cause rotting and insufficient oxygen levels.

As the plants grow larger, and your lights are moved higher, the light will become more scattered and less effective. The plants will either need stronger artificial lighting, or to be moved outdoors into the sunlight.

Hardening Off Pepper Plants

After the risk of frost has passed in your area, you can begin hardening off your pepper plants. “Hardening off” is the process of transitioning your plants from indoors to outdoors.

It may be tempting to simply put your plants directly into the ground, but this is likely to cause shock to the plants. Shocking your plants can cause stunted growth, and even yellowing and death. The proper method is to gradually keep the plants outside for longer and longer. Doing so allows your pepper plants to get used to the elements, like rain, wind, and varying temperatures.

Here is our method for hardening off plants:

  • 1st week: 20 minutes sunlight, or 1 hour of shade
  • 2nd week: 1 hour sunlight, or 3-4 hours of shade
  • 3rd week: 1.5-2 hours sunlight, or all day in shade
  • 4th week: Transplant outdoors permanently

This can be time consuming and tedious, but if you keep your plants on a tray or a wagon, it can make the moving process easy. You can also do this more aggressively, as our method is very conservative and safe.

For a full pepper growing guide, read our article on growing Habanero peppers here!

Once your plants are used to the outdoors, you can transplant into the ground, or large nursery pots for the season. Make sure they get the nutrients and sunlight they need. Enjoy and good luck!

Calvin Portrait

Calvin

One of the original PepperGeeks! When Calvin isn’t gardening or learning more about peppers, he might be traveling new places or playing some music.

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