Best Practices for Growing Peppers

The following information describes best practices for growing peppers.

Soil and Cool Temperatures

• Peppers do best in deep, rich soil with good drainage; prepare the soil by working in 2” of compost to a depth of 8-10”.
• The soil pH should be slightly acidic (6-6.5).
• The minimum soil temperature for transplanting is 55°F at nighttime. In this case, the peppers will be slow, so use “cloches” (gallon milk jugs work well) and warm the soil with plastic sheeting.
• The optimum soil temperature for transplanting is 65°F at nighttime.

Transplanting

• Harden off peppers 7-10 days before transplanting to avoid transplant shock.
• Transplant peppers in the cool of the day to reduce stress on the plants.
• Peppers dislike disturbance of their roots, so handle them carefully.
• Magnesium: Add a dusting of magnesium to the hole and work in before transplanting.
• Don’t overcrowd; allow 15-18” space between plants.
• Plants can be transplanted 1-2” deeper than the root ball.
• Stake when transplanting if the pepper variety is tall (30+ inches) or is known to be heavy bearing.

Watering and Mulch

• Keep the root zone evenly moist. Peppers are intolerant of wet-dry-wet-dry cycles.
• Water well during flower and fruit set.
• Peppers are shallow-rooted, so cover the soil with 2” of mulch to regulate moisture.
• Cut back on water when fruits reach full size and begin to color up. This helps the fruits ripen to their full color more quickly.

Blooms and Warm Temperatures

• Pinch early blossoms. This won’t harm the plants. Instead, pinching helps direct energy into growing a strong, vibrant plant.
• Both nighttime temperatures over 70°F and daytime temperatures over 85°F are hard on peppers. Pollen becomes unviable, and flowers may abort. When temperatures drop, production will resume.
• Protect peppers from scorching sun & high heat (85°F plus).

Pollination

Peppers easily cross-pollinate. Cross-pollination has the greatest effect on the second generation of seeds if you have saved the seeds and attempt to grow the same (pure) variety the following year. 
To avoid cross-pollination:

• Option 1: Keep hot peppers and sweet peppers well-separated (400 ft. between varieties is minimal).
• Option 2: Stagger planting so that different varieties are not flowering at the same time.
• Option 3: Put the hot peppers downwind of the sweet peppers.

Nutritional Needs & Feeding

The following section provides information about the nutritional needs of peppers. 

Nitrogen

• Excessive nitrogen can cause the pepper plants to grow too fast, making them more susceptible to disease and less productive.
• High nitrogen also results in large, energy-consuming plants with lots of leaves and little fruit.

Wait to Feed

• For best fruit development, wait to feed the plants until the first flowers appear and open.
• Place a side dressing of aged compost around pepper plants when the first flowers open, or feed with a low-nitrogen, organic fertilizer.
• Feed again in three weeks.

Mineral Supplements

• Calcium produces fruits that have thick, sturdy walls.
• Phosphorus promotes a strong root system & good fruit set.
• Magnesium optimizes growth, strengthens cell walls, and improves uptake of nitrogen and phosphorus.

Foliar Feeding

Peppers benefit from light foliar feeding every couple of weeks, especially if the crop is heavy, but keep the nitrogen content low.

UC Master Gardener Program of Contra Costa County
2380 Bisso Lane, Concord, CA  94520

Website: https://ucanr.edu/site/uc-master-gardener-program-contra-costa-county