How to Grow Purple Bell Peppers

Popular vegetable garden annuals, all sweet peppers (Capsicum annuum) start off green, though they mature to a rainbow of colors, depending on the variety. Purple bell peppers, a particularly stunning option, make a beautiful and tasty addition to the dinner table.

Although they can be harvested at any size when they are still green, purple bell peppers are sweetest when allowed to mature on the plant. Even purple varieties mature to red like most other peppers, but can be harvested when they reach purple for good flavor. The challenge with purple bell peppers may be having the patience to wait until they are mature to harvest.

For those that do not like to wait, the Purple Beauty pepper (Capsicum annuum, 'Purple Beauty') is an early producer, as it is dark purple at 62 days. These are heavy producers of medium-sized peppers.

The Purple Bell sweet pepper (Capsicum annuum, 'Purple Bell') produces large peppers, 4.5-by-3.5-inch-block fruits, on 24-inch-tall plants. At 70 days, this variety matures to red, but can be harvested early when it becomes purple.

Tequila bell pepper (Capsicum annuum, 'Tequila') is an early producer. While it doesn't reach full color until 75 days after it is started, it can be harvested for good flavor at an amethyst color at 60 days, making it one of the earliest purple bell peppers. Harvest at 75 days for the fullest sweet flavor.

Start seeds eight to 10 weeks before that last expected frost date indoors under grow lights or in a heated greenhouse. Nighttime temperatures may be too cold to start in an unheated greenhouse, as peppers need a consistent soil temperature of about 70 degrees Fahrenheit to germinate. Fill small pots with drainage holes with seed starting mix, place three seeds in each pot and cover with 1/4 inch of mix. Seeds will germinate in about seven days. Keep the containers consistently moist, but not soggy by using a hand-held spray bottle to water.

When plants are 4 inches tall, thin to two plants per pot by cutting the weakest stem just above the soil line with scissors that have been sterilized with an alcohol wipe to prevent the spread of disease. Allow the two seedling to grow together to increase production. At this point, a watering can may be used to water seedlings.

Begin hardening off seedlings after eight to 10 weeks when they are several inches tall and after temperatures have reached at least 60 degrees during the day. Place the seedlings out in the sun one hour the first day, then bring them in. The second day, leave them out two hours. Increase outdoor time by one hour each day until they have been outside all day, then leave them outside overnight. After this, they are ready to transplant. If plants are being purchased, they are already hardened off and ready to plant outside. 

When soil temperature reaches at least 65 degrees F, prepare a space in full sun. Peppers will not grow and produce fruit in an area that gets less than 6 to 8 hours of sun a day. Remove all grass and weeds. Peppers require well-drained, loose soil amended with organic matter. Work 3 to 6 inches of compost into the planting site. Remove all grass and weeds.

Use a trowel to dig a hole slightly larger around than the root ball of the pepper plant and deep enough that the top of the root ball is even with the surface of the soil. Fill the rest of the hole with soil after the pepper plant is in position. Place additional two-seedling sets -- or single plants, if purchased -- 18 to 24 inches apart.

Water thoroughly after planting and continue giving plants 1 to 2 inches of water weekly. If your conditions are extremely hot and dry, daily watering may be required.

Once blossoms start forming, water with a water-soluble general fertilizer, like a 10-10-10 mixture. Add 1 tablespoon of fertilizer to 1 gallon of water and soak the plant and surrounding area. One gallon of mixture should water about four plants.

Purchase plants from a nursery, garden center or farmer's market if indoor seed starting isn't possible.

Pepper plants can grow so large they require caging to keep from falling over. Place the cage over the plant after planting to keep from damaging the root system.

Fertilize pepper plants again with the water-soluble mixture after the after the first set of peppers have emerged.

Harvest mature peppers daily to prevent rot and pest damage to fruits. When the pepper is in full color for the variety, hold the stem with one hand and gently pull off the pepper with the other. If the pepper doesn't easily come off the plant, use sterilized pruning clippers to snip the pepper from the plant. Never tug or pull on plants because this can cause stems to break.

To keep from transferring disease to the pepper plant, wipe the blades off with alcohol before using.