Starting Peppers By Seed: 10 Tips For the Strongest Seedlings
Peppers–especially hot peppers and chiles–have a bad rap for being difficult to start from seed, but that doesn’t have to be the case. There’s no reason you can’t grow your own peppers from seed, even if you’re just getting started gardening.
The biggest issue some growers have is the time it takes to germinate pepper seeds. Some varieties of hot peppers take a month or more to sprout–proving that peppers aren’t necessarily difficult, but they do take time.
If you approach pepper seeds with a little patience, a grain of humility, and our tried-and-true growing advice, you’re sure to have your best year for peppers yet.
10 tips for growing the best peppers
Like any seed, pepper seeds want to grow–it’s what they were designed to do. But because peppers aren’t native to our climate, we have to do a little extra work to make them comfortable enough to germinate and happy enough to keep growing.
1. Start with quality seeds
For the best results, start with the freshest seeds from a trusted source. Your pepper seeds don’t have to be organic or heirloom–in fact, disease-resistant hybrid peppers are often easier to grow than specialty seeds–but non-GMO seeds are a must.
Open your pepper seed packets and inspect your seeds before you begin sowing. Seeds that are less than two years old will germinate better than older seeds, and plump, cream-colored seeds are more likely to produce healthy plants than shriveled, discolored seeds.
2. Use a high-quality, well-draining seed-starting mix
Potting soil mixes are not ‘one size fits all’, so make sure you have a growing medium that is specifically designed for seed starting. Seed-starting mixes generally have a lighter texture and hold moisture a little better than soilless growing mediums made for mature plants. Seed-starting mixes are also lighter on fertilizer, which pepper seedlings appreciate. Jiffy Peat Pellets are another great option.
3. Soak or pre-sprout seeds
While not necessary, you can soak pepper seeds prior to planting them to encourage faster germination. Place pepper seeds in a bowl or jar of room temperature water for up to 24 hours to soften the seed coat and break dormancy.
If you want lab precision and real results, you’ll appreciate the Pepper Seed-Starting Kit. Each kit contains a packet of two natural compounds proven to increase hot pepper seed germination up to 50%. Simply dissolve the compounds in water and dip hot pepper seeds in the solution to jumpstart germination.
Alternatively, you can pre-sprout pepper seeds by wrapping the seeds in a moist paper towel and placing the paper towel in an unsealed plastic bag. The bag will serve as a mini greenhouse, trapping heat and moisture and encouraging any viable seeds to sprout.
Once most of the seeds have sprouted, carefully transfer the seeds to a soil-filled tray, planting each one ¼ to ½ inch deep.
4. Use a Dial Seed Sower
Pepper seeds are tiny! And while bell pepper and sweet pepper seeds are fine to touch with your hands, hot pepper seeds contain a chemical compound called capsaicin that can irritate your skin. Should you touch your eyes or lips after handing hot pepper seeds, the compound can cause an unpleasant burning sensation.
Be sure to wear gloves when you sow hot peppers, or use a Dial Seed Sower to minimize your contact with the seeds. The Dial Seed Sower is easy to load and quick to dispense, making sowing multiple flats of pepper seeds a breeze. It’s adjustable, so you can use the same sower for your other seeds, too.
5. Sow pepper seeds at the proper spacing and depth
You can start pepper seeds in any size container you have available to you, but we prefer 72-cell flats to save space. The Deluxe Seed-Starting Kit contains everything you need to start 144 pepper seedlings. Sow 2 seeds in each cell so that you’ll have at least one seedling sprout in each cell–you can always pluck out or tease apart double-seeded cells.
Pepper seeds only need to be planted ¼ to ½ inch deep—any deeper and the seedlings won’t sprout, but plant the seeds too close to the surface and they’ll be washed away the first time you water. A good rule of thumb, regardless of what kind of seed you’re sowing, is to plant the seed twice as deep as it is wide.
I like to fill a tray most of the way full with pre-moistened seed-starting mix, sow the seeds on top, and then cover the whole flat with another thin layer of soil. You can also fill the seed trays full, then use a pencil or a chopstick to make a small, shallow hole in each cell that you can drop the pepper seeds into–just mark which cells you’ve completed by gently closing the hole.
6. Use a humidity dome
Pepper seeds require even, consistent moisture to germinate. You don’t want to overwater your pepper seedlings, drenching them in soggy soil–that would be worse than letting the seeds dry out. However, you do want to check the seed trays every day for moisture, and only water when needed.
The best way to keep your seed trays evenly moist is to use a humidity dome. These inexpensive, clear plastic lids trap heat and moisture, retaining warmth and water right where pepper seeds need them. As helpful as humidity domes are in the beginning, once the majority of the pepper seeds germinate, you’ll want to pop the dome off of the seedling tray so as to not stunt seedling growth.
While you can overhead water pepper seedlings, bottom watering is a safer bet. Bottom watering is also incredibly easy, but you’ll need a watertight tray that nests underneath each seedling tray. When you’re ready to water, fill the bottom tray with water and set the seedling tray down in it. Allow the seedling tray to absorb the water for 30 minutes or so, and then lift the seedling tray and dump the excess water.
Any time you go to water, check the seed trays for moisture first. If the surface soil is wet, you don’t need to water at this time. If you can lift up the seed trays and see that the soil is dry, it’s time to water.
Like most plants in the nightshade family, peppers don’t like to be overly wet. Your pepper seedlings will tell you when they’re thirsty–they’ll begin to wilt. But overwatered peppers may also have yellow, wilted leaves, so the only sure way to tell if your pepper seedlings need water is to check the soil itself.
7. Use a heat mat
The best way to get more pepper seeds to germinate faster is with a heat mat. The ideal temperature range for pepper seeds to sprout falls between 65-75℉, according to this study by the University of California. You can easily maintain this soil temperature by using a heat mat and thermostat.
Humidity domes help with both moisture and warmth retention, but the bottom heat emitted from a heat mat is irreplaceable when it comes to germinating pepper seeds. Make sure that you only use a heat mat in conjunction with a thermostat, so that you are always in control of the soil temperature.
8. Start pepper seeds at the right time
Perhaps the most important factor that will determine the success of pepper seed germination is timing. Start your pepper seeds too early, and the low-light, cold days will only result in leggy, spindly seedlings. Wait too late to start pepper seedlings and you won’t get a full harvest before the first killing frost of fall.
Many sweet and bell pepper seeds only take a week or so to germinate, but hot pepper seeds may take anywhere from two to six weeks to sprout, depending on the variety. Most growers start peppers between eight and ten weeks before their anticipated last frost date, and don’t transplant pepper seedlings outside until two or three weeks after the last frost.
Research your area’s average last spring frost date and count back the number of weeks suggested for germination, then add two to four weeks to arrive at a good date to sow pepper seeds. This will allow enough time for germination and gives you plenty of wiggle room to work with, should some of your pepper seeds not sprout. The extra few weeks will allow pepper seedlings time to develop strong enough root systems to survive transplanting.
The bottom line: do your research on the pepper varieties that you plan to grow, overestimate how much time germination may take, and be patient!
9. Use a fan to promote better airflow
It may seem counterintuitive, but running a fan in your seed starting room or greenhouse will actually encourage pepper seedings to be stronger and healthier. A box fan or oscillating fan will promote better airflow, moving stagnant air out and reducing the risk of fungal diseases like damping off–a nasty soilborne disease that weakens seedling stems, causing them to bend over and break.
Air movement actually forces seedlings to grow stronger stems and more robust root systems, so the young plants will be better equipped to handle the transition outside.
10. Use a grow light
Peppers are fruiting plants, and as such require at least eight hours of sun a day, if not more. It really benefits peppers seedlings to have anywhere between 10 and 14 hours of sunlight a day, but eight hours is the bare minimum.
Although a sunny windowsill might seem to suffice, indirect light just isn’t as effective as direct light. Pepper seedlings under an indirect light source will stretch for the light, resulting in spindly, unhealthy stems. And once you have leggy plants, you can’t undo the damage that has already been done.
If your pepper seedlings aren’t in a greenhouse or hoop house, the best thing to do is keep them under a grow light. Look for a full-spectrum LED or fluorescent bulb, and keep the bulb at least a foot away from the tops of the plants at all times. This Tabletop Grow Light System is designed so that the bulb moves with your plants—you can move the bulb higher as the plants grow taller.
If you still feel like you need a little more information to confidently sow pepper seeds of any kind, you’ll appreciate the Growing Peppers From Seed planting guide. This 36-page guide is part detailed instruction manual, part intriguing history book, and is sure to excite any pepper enthusiast.
In the right environment and with the proper care, peppers will grow flawlessly from seed. Have some patience with your seeds, use these tools and tricks to speed up germination, and you’ll be rewarded with a bounty of colorful, tasty peppers that you won’t find at any grocery store!