MSU Extension

Peppers are popular in Michigan gardens, partially because there are so many varieties available from sweet to very hot. They are tropical plants grown as warm-season annuals here.  Peppers are often harvested in the immature green stage for use in salsas, salads, for stuffing, roasting, and for added flavor in many cooked dishes. Most peppers ripen slowly to red or other colors at maturity.

How to grow peppers

Pepper plants grow best in warm, well- drained soils of moderate fertility. The plants are not particularly sensitive to soil acidity, but best results are obtained in the 6.0 to 6.8 pH range. Adjust soil fertility as indicated by soil test results. Fertilizers of a 1-2-2 ratio, such as 5-10-10 or 8-16-16 are often used for growing peppers. A soil enriched with plenty of compost or other organic material will require less fertilizer. Peppers may also be grown very successfully in containers.

Peppers thrive when temperatures are warm. Being sensitive to the cold, planting should be delayed until the danger of frost is past in the spring. Ideal temperatures are 70°F to 80°F during the day, and 60°F to 70° F at night. A tip for helping the soil warm up more quickly is to use black plastic mulch to cover the soil around the peppers.

Extremely high temperatures (90°F or above) during flowering often results in blossom drop. Fruit that sets when temperatures average above 80°F may be small and poorly shaped due to heat injury to the blossoms. Temperatures below 60°F at night will also result in blossom drop. At temperatures below 40°F, peppers may show some chilling injury.

A shortage of water at bloom time can also result in blossom drop or failure to set fruit. The plants produce the best crops when temperatures are between 65°F and 80°F and the soil is regularly supplied with moisture (approximately one inch per week), as the fruit and blooms may die with transplanting.

Peppers are usually grown in home gardens as transplants rather than by direct seeding. If you are buying transplants at a local garden center, select stocky, sturdy plants that have three to five sets of true leaves. Avoid plants that already have flowers and fruit as the fruit and blooms may die with transplanting.

In a traditional garden layout, space plants 18 inches apart in rows 24 inches apart or more. Water soil in the ground and transplant container thoroughly before and just after transplanting. Avoid planting under conditions that will stunt the plants and lead to poor production, such as cold weather, lack of sufficient soil moisture or lack of sufficient fertilizer.

Tips for an abundant crop

After the plants are well established, apply approximately an inch of organic mulch to conserve soil moisture, prevent soil compaction and help suppress weed growth. 

Once fruits have begun to set, an additional side-dressing of fertilizer will help promote larger fruit. Use a 12-12-12 analysis fertilizer or other high nitrogen fertilizer at the rate recommended on the package.

Control weeds by hand-pulling or lightly hoeing to avoid injury to the plant roots. Avoid disease problems by properly watering early in the day so leaves dry quickly. If possible, use soaker hoses to water just the roots and not the leaves.

Harvesting and storage

Bell peppers are usually picked green and immature but when they are full-sized and firm. If they are allowed to ripen on the plant, they will be sweeter and higher in vitamin content. Other peppers are usually harvested at full maturity.

Be careful when breaking the peppers from the plants as the branches are often brittle. Hand clippers, scissors, a sharp knife or pruners can be used to cut peppers from the plant to avoid excessive stem breakage. Use gloves or wash hands immediately when harvesting hot peppers to prevent burning skin. Avoid touching eyes or mouth after harvesting peppers so the capsaicin oil doesn’t burn these sensitive areas.

The number of peppers per plant varies with the variety. Bell pepper plants may produce six to eight or more fruit per plant.

In general, peppers have short storage life of only one to two weeks. Cool, moist conditions (45°F to 50°F and 85 to 90 percent relative humidity) are ideal for storing peppers. Another option is to wash, cut and freeze the peppers.

Suggested varieties

The choice of variety is important and depends on the gardener’s preference. Many excellent heirloom and hybrid varieties are available. Some suggested varieties are:

• Green (sweet) – California Wonder, Bell Boy, Lady Bell, Purple Belle or Chocolate Bell.
• Yellow (sweet) – Gypsy or Summer Sweet.
• Small Red (sweet) – Cherry Pick or Sweet Cherry.
• Banana – Sweet Banana.
• Hot – Cayenne, Jalapeno, Hungarian Wax or Red Cherry.
• Pimento – Sunnybrook or Early Pimento.

For those who like their peppers hot: Bhut Jolokia, sometimes called the ghost pepper, is considered the hottest pepper. It has one million SHU (Scoville heat units) on the Scoville Scale, a measurement of the spicy heat of a chili pepper according to its capsaicin content. Remember that growing very hot peppers may present a danger of painful burns to children or pets, and when harvesting consider wearing disposable gloves.

Written by Linda Whitlock, MSU Extension-Kalamazoo County, 2010. Reviewed by Bridget K. Behe, MSU Horticulture, Jennie Stanger, MSU Extension-Monroe County and Rebecca Finneran, MSU Extension-Kent County.