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Sowing a garden and watching it spring to life is a rewarding feeling. However, some vegetables are a little more challenging to start from seed, such as peppers. Now don’t go running off to the nursery to buy starts. To ensure your success, we’ll go over 10 tips for growing peppers from seed.
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Tip #1: Growing Peppers From Seed, Sow Early
Get a head start when growing peppers from seed
You need to start your seeds indoors at least 10-12 weeks before your last frost date. Most zones of the United States don’t allow a long enough growing season to sow the seeds outdoors in your garden. On top of that, pepper plants will not produce ripe fruit until they are a couple months old. When you consider the fact that the average outdoor growing season is only about four months long for much of the US, then surely you can see the importance of sowing the seeds so early.
Some things to keep in mind. Pepper plants are not tolerant of frost. They are a warm weather crop and shouldn’t be put outside until the ambient temperature is consistently over 50F. This will ensure you are well past your last frost date. Additionally, the first frost at the end of the season will kill the pepper plants. You can find your first and last frost dates on the Farmer’s Almanac.
Tip #2: Use Large Cells
Think big when growing peppers from seed
Standard seed starting trays (72 cells per 10×20 tray) will work just fine for many types of vegetable. However, pepper seeds are started much earlier than most vegetables and the plants will ideally be pretty large by the time you move them outdoors.
If you start with standard seed trays, your pepper seedlings will quickly become rootbound. This will create the need to transplant into larger containers. Each time you transplant, the seedling’s growth will be delayed a few days to a week while it recovers from the transplant shock. Sowing in large cell seed starting trays or 4″ nursery pots will not only save you time, but the seedlings will have a longer undisturbed growth period.
When it comes to seed starting trays, our personal favorite for peppers (and other large vegetables) is the Burpee SuperSeed 16XL. They are very durable trays with 2″x2″x2″ cells. Now I know that it doesn’t sound like much of a size jump. However, each cell of the 16XL holds four times the volume of soil as a standard cell.
Check out our page of the best seed starting trays for more info.
Tip #3: Use Sterile Seed Starting Mix
Don’t use garden soil when growing peppers from seed
This tip applies to any plants you want to grow from seed, but especially peppers. Pepper seeds may not germinate for two weeks or longer. The humidity required for seed germination is also an ideal environment for mold and mildew to grow. Using fresh, sterile soil ensures that there are no fungi, mold or other pests that could harm the seeds or seedlings.
A good quality seed starting mix is not only sterile, but also light and fluffy and drains well while retaining moisture. Garden soil is usually too compacted, poorly draining, and not sterile. Any unused batch of last year’s parent seed mix that was stored outdoors will almost certainly contain pests. Aphids are hitchhikers that often make their way indoors on old soil. They will devastate your seedlings. It is advisable not to bring soil from outside.
Check out our page of the best seed starting mixes for more info.
Tip #4: Preparation Is Key When Growing Peppers From Seed
Moisten the soil before filling your seed starting trays
Moistening the soil before filling containers is an important tip when growing peppers from seed. As mentioned in the previous section, fungi and mold thrive in a moist environment and adding too much water to the soil will only encourage their growth. Soil that is too wet can also cause seeds to rot below the soil surface.
How do you know if the seed starting soil has the right moisture?
Place your favorite seed mix in a bucket or container. Periodically, as you add water, grab a handful of soil and squeeze it firmly into your fist. When you can barely get a few drops of moisture out of the soil, stop adding water. A compacted clump of soil should hold its shape when you open your hand, but crumble easily when disturbed. This is the perfect amount of moisture for sowing seeds.
Tip #5: Plant Multiple Seeds Per Cell
There’s nothing worse than empty cells in the midst of a bunch of sprouts. It becomes particularly troublesome if you only plant one cell of each type of pepper. To combat this problem, consider planting at least two, if not three, seeds per cell. This way you increase the chances that at least one seed will germinate.
What if all the seeds sprouted?
You have two options. Simply wait until the seedlings are about 2 inches tall and have a set or two of true leaves, then cut the weakest seedlings off near the soil, leaving the strongest seedling. Or you can pop the seedlings out of the cell and gently pull them apart to plant separately. Just be careful if you choose the latter option so as not to damage them.
Tip #6: Create a Humid Environment
Moisture matters when growing peppers from seed
As with any seed, it is important to keep the seed starting soil moist. This is one of the most important tips for growing peppers from seed. Using a properly fitted humidity dome creates a nice, humid atmosphere in the trays from top to bottom.
Pepper seeds have a thick shell. Without proper humidity, you can end up with helmet heads, also known as helmeting. The seedling will emerge with the seeds still covering the top leaves. Above the moist soil surface, the seed coat dries. Having the proper humidity keeps the shell pliable and allows the top leaves to break free.
Use a properly fitting humidity dome with vents until the seeds sprout. Once all seedlings in your trays have sprouted and have shed the seed, it’s time to wean them from the hood. Doing this slowly is best since the air outside the dome is less humid. If your dome has vents you can open them more and more over a few days. If your dome doesn’t have vents, start propping up the hood more and more each day.
Tip #7: When Growing Peppers From Seed, Provide Warmth
Using a seedling heating mat when growing peppers from seed has become standard. Without them, the seeds would take more than two weeks to germinate. Not only does this complicate your planting schedule before the last frost, but your seeds could potentially rot underground during that time.
The use of a seedling heat mat simulates springtime warming of the soil. It tells the seed it’s time to sprout. The recommended temperature for germinating pepper seeds is between 75 and 85 degrees. If you cannot maintain this temperature range in your growing area, consider using a seedling heat mat and thermostat controller.
Tip #8: Don’t Over Water Seedlings
Overwatering is arguably worse than underwatering
Overwatering is perhaps the biggest concern for budding gardeners. While this can be a problem for any plant, starting from seed, peppers appear to be particularly sensitive to constant root moisture. Overwatering can lead to many problems. The most common are dampening off, root rot, and edema.
How do you know when to water pepper seedlings?
It is best to get used to the weight of the containers before and after watering. Once you become familiar with these weights, you can easily tell when to water by simply lifting the containers. If your seedlings are pale green or slightly yellowed, overwatering may be the culprit.
Tip #9: Easy On The Fertilizer
It is often seen on gardening forums. A new gardener, concerned about an apparent problem. In an effort to combat the issue, they use three different fertilizers in the same week. This inevitably leads to ruin. Plants recover slowly when correcting deficiencies but they can burn up overnight from too many nutrients. Nothing good happens fast when gardening.
Over-fertilizing, like over-watering, can aggravate the existing problem. One of the most common problems is leaf yellowing, an overlapping symptom of overwatering and nutrient deficiencies. When you see large leaves turning yellow, it’s often a sign of nitrogen deficiency. The plant is consuming the nitrogen from the large older leaves so it can continue putting on new growth. This is not a tragic problem and is easily corrected with small amounts of water-soluble fertilizer.
How much fertilizer should be used when growing peppers from seed?
It is recommended to use nutrients at a concentration of 1/4 after about two weeks of life. Then slowly increase the concentration over several weeks until the plants can tolerate the nutrients in full potency. If you’re using an inert seed starting mix you can fertilize every time you water. If your soil contains compost or other natural fertilizers then you may only need nutrients once every two weeks, if at all.
Tip #10: Provide High Quality Light
Don’t skimp on lighting when growing peppers from seed
When growing peppers from seed, you need to provide them with adequate light once they sprout. Without high intensity light, the seedlings will stretch and become leggy. A windowsill will never provide enough light, even a south facing window. I can’t stress that enough.
Your pepper seeds will grow indoors for several weeks and will be several inches tall when you put them into the garden. If you plan on growing peppers from seed every year, I advise you to invest in a good grow light. LED grow lights have gotten much better over the last few years and at a better price. We use and love Viparspectra LED grow lights. Our favorite is the XS2000, which covers the entire surface of our 4’x2′ grow tent. It’s also powerful enough to grow full-size plants, which is what we usually do. If you are on a budget, BLOOM PLUS is another great LED grow light.
Check out our page on the best grow lights for seed starting to learn more.
Bonus Tip: Use an Indoor Grow Tent
Create the perfect environment for growing peppers from seed
Using a grow tent has many advantages. For starters, they seal fairly tightly and can help keep humidity levels high. Low humidity can cause the leaves to curl and require more frequent watering as the seed trays dry out more quickly.
In addition, thanks to the reflective Mylar coating, you use every photon emitted by your grow lights effectively. Having the shiny walls of the tent on all sides, the diffused light is reflected back to your plants. Your plants will grow sturdier as they bask in the light that illuminates them from all directions, not just from above, when using an indoor grow tent.
Growing peppers from seed can be challenging at times. It may take you a few tries to perfect the technique but don’t give up. Learning to start from seed opens the doors to more varieties that you won’t find in local nurseries. I hope you found this page useful. While you’re here, take a look at our other seed starting articles.
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