Have you ever dreamed of picking spicy and fresh homegrown peppers straight from the vine? A greenhouse gives gardeners the upper hand, allowing successful pepper growing well beyond the typical season. Even a cold frame can allow for pepper-growing fun when the temps drop. Though both environments can provide the warmth that peppers love, not all varieties play nice.

These seven tips will give you an edge to grow perfect peppers packed with flavor (say that three times)!

7 Tips for Greenhouse and Cold Frame Peppers

Choose the Right Greenhouse Variety

There are thousands of pepper varieties worldwide, and choosing the best ones to plant is key. The following list of peppers is ideal for controlled environments like a greenhouse or cold frame.

• Bell peppers
• Habaneros
• Cayenne
• Mini-bell
• Jalapenos

Create the Right Greenhouse Environment

Peppers need full sun and a consistent temperature of 70-90 degrees to blossom and fruit. In some areas, such as the south, a greenhouse can get far too hot to grow peppers in the summer. Consider planting them in pots or raised beds outside if that’s the case.

For northerners, a greenhouse or cold frame can be perfect for these sun-loving plants. No matter where you grow your peppers, try not to mix plants with other species from the nightshade family, like tomatoes, eggplant, and potatoes, because they can share the same pests and diseases. Instead, plant your peppers with companion plants like carrots, nasturtiums, basil, cilantro, and marigolds for natural pest prevention.

Provide Healthy Soil and Compost

Peppers love to eat, and soil that lacks nutrients can madden them to the point where they produce smaller fruit, yellowed leaves, and less-than-impressive growth. One or all three of these mean a reduced harvest, so make sure you hit that sweet spot for healthy soil and commit to an optimal feeding schedule.

• Ideal pH: Peppers thrive in 6.0-7.0 Ph.
• Soil Prep: Add compost and organic matter before planting peppers.
• Fertilize: A fertilizer high in potassium and phosphorus can boost fruit production. However, a balanced 10-10-10 should be used at a minimum.

Water with Care

Peppers aren’t too thrilled with water. They despise soggy roots and will throw a fit with blossom end rot. It’s best to water your peppers deeply, 2-3 times weekly, rather than everyday.

If you’re growing peppers in a cold frame, water them early in the morning so the soil soaks up excess moisture before nightfall.

Drip irrigation systems are excellent for peppers and keep the soil hydrated without over-watering. Peppers planted in raised beds or pots dry out quickly, which means peppers can soon take a turn for the worse. So, make sure you check potted peppers frequently.

Stake and Support

If you’re growing your peppers in a greenhouse or cold frame, they’re happy soaking up the sun, which means they tend to get bigger and even heavier than their outdoor neighbors. You’ll need to support the plants with cages, trellises, or stakes to keep them from toppling over. You should also prune the lower leaves so light can penetrate the base of the plant. 

Bonus tip: Although it may seem counter-intuitive, removing the first few flowers on your plant will help redirect energy to leaf and root growth, encouraging even bigger peppers later. 

Prevent Pests in Your Greenhouse

They’re everywhere in the garden! Spider mites, whiteflies, and aphids can attack pepper plants and spread quickly. Beneficial insects like ladybugs can help solve the problem. If pests get out of hand, spray your plants with neem oil or insecticidal soap. If you’re growing peppers in a cold frame where plants are close to the earth, keeps slugs and snails away naturally with crushed eggshells or a sprinkle of diatomaceous earth.

Happy Harvesting

Ready to enjoy the fruits of your labor? Harvest your peppers once they’ve reached their ideal color and size. Be sure to use pruning shears to avoid damaging your pepper plants.

If a frost is on the way and you’re growing your peppers in a cold frame, pick them a little earlier and let them ripen indoors.

Whether jumpstarting seedlings or extending your harvest, a greenhouse or cold frame provides the perfect environment to grow peppers year-round. Spice up with your garden with a few pepper plants and see if your skills can take the heat.