If you haven’t already, be sure to check out our Basic Growing Tips. It provides a compact overview and is enough for most growers to get started. Below is our step-by-step growing guide for those who wish to know more of the finer details involved for maximizing results.
We'll continue to update this guide based on new information and experiences, so be sure to come back for the latest. Also, we post frequently to our Facebook page with updates on new things we are seeing and trying.
When picking peppers for seed harvesting, be sure to select healthy peppers from healthy plants. Avoid diseased plants or fruit that's rotted or eaten. It's possible for diseases to be passed from seeds to the next generation of plants.
Allow peppers to fully ripen before picking to ensure their seeds are fully formed. A pepper is completely ripe when it changes to its final color. Most peppers start as green, but then change to a red, orange, yellow or ivory color when fully ripened. Some peppers will change to an intermediate color, or colors, before arriving at their fully ripened color. If unsure, check the internet to research the ripened color for a desired pepper.
When the goal is to produce offspring plants with traits similar to the parent plant (which is usually the case), you'll want to isolate this plant from other pepper plants to prevent cross-pollination, where wind or insects take pollen from nearby pepper plants and pollinate the target plant. This readily happens with closely planted pepper plants, even when the plants are two different pepper varieties/cultivars.
Once picked, remove as much pulp and fruit from the seeds as possible. Wear gloves! Touching hot peppers while cutting can be very painful when hands touch other parts of body – pain can last for 30 minutes or more. Also consider wearing safety glasses, as it’s possible for a seed to get flung up into an eye (this has happened to us and pain was extreme). If you're looking to harvest a significant amount of seeds, consider using a blender.
After extraction, put seeds on a paper towel or into a small cup to let them dry. When dry, usually in 24-72 hours, you can package the seeds for storage. Again, gloves are recommended – even seeds several years old can have skin irritating residue. We place our seeds in small paper or plastic sampling cups, using one cup per seed variety (baggies and envelopes also work). We stack the cups adding an empty cup to the top, and use masking tape then to keep the stack intact when laid on its side. It's best to store seeds in the refrigerator to keep them in a dormant state.
Typical recommendations call for planting pepper seeds indoors 6-8 weeks before transplanting outside. We prefer 8-10 weeks as that provides more time for the varieties that take longer to sprout and allows for replanting any failed seed cups.
We typically start seeds in 4-inch pots with good drainage holes. Disposable plastic drinking cups also work with 3 1/4" holes drilled in the bottom. The 4" pots give seedlings a couple of months to grow indoors without getting too root-bound. As long as the seedlings have good water and light, they should stay healthy and grow to a decent size indoors while waiting for the outside temperatures to sufficiently warm.
Take seeds out of refrigerator 24 hours before planting. Some suggest using a strainer to lower seeds into a hydrogen peroxide bath for a minute or two followed by a rinse with tap water to help kill mold or fungus spores which could damage young seedlings. We've done it with and without the peroxide bath and haven't noticed any difference.
We use Miracle Gro® Orchid Mix, Miracle Gro® Organic Choice, or any other store-bought organic blend as our starting potting soil. Other sites have done tests on a variety of starting soils for pepper plants and had the best results with the organic blends. Using these, our germination rates have been solid.
Be sure to leave enough room at the top of the starter cup so plastic wrap (or other moisture retaining cover) can be placed without interfering with the seedling as it sets its first pair of starter leaves. An inch or two of clearance should be enough.
We make a seed starter solution with one tablespoon of Miracle-Gro® mixed in a gallon of distilled water. Immediately before planting seeds, we water the starting cups with seed starter solution to dampen and slightly compress the soil. We do this before planting the seeds, because the overhead watering is quite disruptive to the soil – potentially moving and burying newly planted seeds deeper than intended.
We plant each starter cup with 3-4 seeds about 1/8 inch deep. Once planted, we'll label the cup and cover with plastic wrap to retain moisture. If the soil dries before seedlings sprout, we'll temporarily pull back the plastic wrap and use a disposable, cafe-style coffee cup with the sippy lid to gently apply more seed starter solution – trying minimize soil disruption.
We avoid the peat pellet discs found in seed starter kits. Some sources say never use them for peppers, others say they've used them and had good results. When we used pellets, we had lower germination rates. Also, compared with 4" pots, seedlings will need to be transplanted at a smaller size, or possibly require an intermediate indoor transplanting. If the peat pellets are used, be sure to remove the outer netting prior to transplanting. One year we didn't do this and found the outer netting didn't decompose during the growing season. It resulted in severely limited root systems and modest plant growth.
We've also experimented with using old K-Cups and had good success (emptied coffee and removed filter). We'd recommend planting the K-Cups about 4-6 weeks before transferring outdoors. While the seedlings become root-bound much sooner in the smaller container, we've found as long as they're kept watered, the seedlings will stay alive and grow quickly once transplanted into a bigger container. Discarded egg cartons are another eco-friendly way to start seedlings in a small space.
Once planted, seeds should start sprouting in 7-30 days – depending on the variety. While normal indoor temperatures will work, warmer temperatures are better as they result in quicker and more robust germination. Using an incubator, heating pads or grow lights to maintain 80-85°F during daytime hours and normal household temperatures at night is ideal. Though, simply placing your seed container(s) on top of the refrigerator or a high shelf for an added couple of degrees will also work reasonably well.
Once seedlings start to appear, remove plastic wrap or any moisture retaining cover and place in sunny location indoors or under a grow light. Also, discontinue use of seed starter solution and use regular tap water that has sat out for at least 24 hours to remove the chlorine. Water from an aquaponics system or aquarium is even better as long as those sources aren't being treated with chemicals.
Seedlings are rather fragile when they first sprout and overhead watering can knock them around if not done gently. If seedlings get stuck to soil, gently use a pencil or toothpick to get under them and lift them off the wet soil a little. They'll usually straighten out again pretty quickly. If overhead water is creating too much havoc for the young plants, a disposable coffee cup topped with a sippy lid works well.
Be sure to let the seedlings partially dry out in between watering – soil should still be moist, but not damp. Continuously overly damp conditions can deprive roots of oxygen as well as produce mold which will destroy the seedlings. Pepper plants will start to yellow if their roots aren't able to dry out periodically. If you see mold or yellowing leaves, stop watering and increase light and airflow until soil is mostly dry before re-watering.
Some recommend watering new seedlings with diluted fish fertilizer, like Alaska brand liquid fish fertilizer. However, fish fertilizer has a very distinct (and bad) smell. We tried this one year and our basement stunk. We've since forgone using it and have had good results.
If seedlings are leggy or stringy – meaning growing tall and weak with bending, twisting or leaning – that likely means the light source isn't strong enough. Increasing light intensity – a south-facing window or moving the grow light closer to the plants – should help. A few years back, we were using the red/blue LED grow lights and they were tending to produce stringy plants. In doing some reading, we found others were having similar results with the red/blue LEDs. We switched to full-spectrum LED grow lights with a higher light intensity and seedling growth is now sturdy and robust.
If some seedlings are stringy, you can sturdy the plants by adding more soil to top-off containers. It's okay to clip or bury the bottom few sets of leaves. Gently pack soil down to bring plant(s) upright and toward the center of the container.
Pepper plants need good drainage, though overhead watering of well-draining seed starter cups leak a lot of water and leached soil nutrients. Placing the cups into a plastic tub and reusing captured water is one approach, though that adds a barrier keeping heating mats from warming the soil. It's also extra work to remove cups and reclaim the water.
This spring (2019), we experimented with clear plastic drinking cups with no holes. While it did reduce water usage and retain nutrients, it was time consuming to check 50 starter cups individually for their water needs. It was easy to over-water a cup or two – which if we noticed, we'd then need to drain into other cups. It was just as easy to under-water, resulting in droopy plants. Ultimately, we lost several seedlings – most likely due to over-watering or lack of oxygen for the roots.
With the varieties we lost, we tried again with a different approach. Using the same plastic cups, we added a small hole about 1/2" up from the bottom – filled it straw for the first inch and the rest with organic potting soil. The intent being to conserve more water/nutrients while not allowing the soil to get too wet. The straw layer – we hoped – would soak up water, create air gaps, and slowly decompose to replace lost nutrients. We've only tested on a few cups, but had good results so far. We'll likely do a larger test on these next year.
When seedlings are couple of inches high – if you like – choose the strongest seedling in each container and cut the rest to free up room for the chosen seedlings to grow.
Let soil dry out slightly and use a fork to gently loosen soil around the seedling(s) to be relocated. In most cases while the soil is being loosened, the seedlings should be able to be pulled gently to remove from the container with the roots intact. They can then be transplanted into another container. If doing this, it’s best to wait until seedlings are around 2-inches tall. Younger seedlings are easily damaged and may not survive transplanting.
Alternatively, if your seed starter cup has enough room, you can continue to keep the seedlings in the same cup. When time to transplant, using care, they should still be able to be separated. Or, the seedlings can be kept together and transplanted into the same pot or garden square. We like doubling/tripling-up some of our plants for the following reasons...
Once the seedlings are around 2-4" tall, it's a good time to start to harden them – weather permitting. Plants taken directly from inside to outdoors can experience a significant shock from wind, changing temperatures and direct sunlight – so it's a good idea to do this gradually. If you have a screenroom/sunroom, that's a great spot to start getting them acclimated. When moving them directly outside, start with 15 minutes a day in a mostly shaded area with filtered light and avoiding overly windy conditions. Gradually increase the time and intensity of sun they receive.
When bringing plants outside early on, be sure to watch them closely as they can quickly dry out or get over-exposed to the sun. If plants start getting droopy, bring back inside or to a shady spot and water their soil immediately.
Small cups offer little protection for their roots, making them more vulnerable to prolonged periods of cold. Brief nighttime temperatures down to 40°F should be fine for mostly hardened plants – ours have handled brief dips to 35-37°F on occasion – though, a prolonged period in that range can kill them. We like to keep our seedling pots in a shallow tray for easier transport during the hardening period.
When plants reach 4-6 inches, they’re ready for transplanting outside. They can be transplanted at a smaller size with consistently favorable weather. In years with good weather, we've planted ours as small as 2", with good results. However, we've transplanted 3" plants during years where the weather turned unexpectedly cold and they were significantly stunted for the next month or so.
It's best to wait until nighttime temperatures are consistently above 50°F – though, they can deal with lower temperatures, if not prolonged. We’ll look at the 15 day forecast, if the vast majority of the predicted nightly lows are above 50°F, with nothing below 45°F, we’ll start transplanting.
Choose a spot where plants will receive full sun, as pepper plants love full sun. You'll see a significant difference in size and fullness between pepper plants in a sunny spot versus a shady one. Also, shady locations tend to increase exposure to pests, particularly garden slugs.
Dig holes deeper than the current container to allow the plant stem to be buried past the first or second set of leaves. If it's an especially stringy plant, we'll bury most of the plant, only exposing the top few sets of leaves. Before planting, we add a few shakes of bone meal to the bottom of the hole and work it into the soil. Bone meal is a great source of the calcium that pepper plants need – especially those belonging to the Chinense species.
If you're planning on transplanting into pots, check out our Planting Peppers in Pots Guide for more details and for information choosing pot sizes and for ideas on reducing the amount of potting soil you need to buy.
If planting into a garden bed, try to transplant in the evening, so the plants have the night to adjust before being exposed to full sun. If planting in pots, we usually put the pots in a semi-shaded area for the first few days before gradually moving them into full sun.
Plants can be vulnerable to sun-scalding and wilting when first transplanted – keep a close eye on them. A little wilting is fine, though if plants wilt significantly in full sun, provide shade and water the ground around them – taking care to avoid watering the wilted leaves. Plants should bounce back quickly, and can be reintroduced to full sun the next day with monitoring.
Inevitably some plants will get bent or even broken early after transplanting. Don’t worry! Bent plants will usually straighten quickly and can be helped with staking. Any broken or damaged branches can be pruned. While looking like misfits at first, they’ll soon start regenerating branches. Most damaged plants will nearly catch up to their peers – sometimes with the added bonus of being bushier and producing more fruit.
Periodically, after transplanting we'll be surprised with an unexpected bout of cold weather. Brief nighttime cold, if not extreme, is usually manageable provided the daytime temperatures get back over 50°F. A prolonged period of day and night temperatures around 40°F, and below, can kill young pepper plants. Moving plants back inside or covering may be needed in those cases. Semi-established transplants coming out of a prolonged cold snap and quickly exposed to warm and sunny weather, can be shocked by the sun and may need temporary shading.
For nighttime temperatures that briefly approach freezing, a plant of several inches and overwintered plants should be fine. For nighttime temperatures a couple of degrees below freezing, we'll bring inside or cover. Covering small plants with doubled-up transparent plastic cups (to trap a layer of air) and dug into the soil slightly can add about 2°F to the outside temperature. Insulated tumblers and buckets can be used for larger plants – if temperature drops are not too extreme.
Now that the plants are outside, liquid fish fertilizer can be used without having to deal with that smell trapped indoors. If used, feed plants every 3 weeks until they start to flower. We typically don't use this – we've found using bone meal, compost, and straw as soil additives to our pots (see what we do) tends to produce strong growth on its own.
A small monthly sprinkling of bone meal is also helpful in providing calcium to the plants as they grow. This is especially helpful for peppers from the Chinense species. If plants have a lot of wrinkly green leaves, it's usually a sign they're calcium deficient. Leaves from healthy plants should be mostly flat. When fertilized with bone meal, the next generation of leaves will usually flatten out.