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MG 292 March 1, 2003

Master Master Gardeners Gardeners

JournalJournal

Culture Because of our relatively short growing sea-son, peppers are best started in the green-house in early April and transplanted in early June after the garden soil has warmed to at least 60-65oF. Sow seeds ½ inch deep in a sterile seeding mix, and keep uniformly moist. You can buy or mix your own sterile potting mix for starting transplants. The mix should include peat, sphagnum or compost to retain moisture; vermiculite or perlite for aeration; and mineral and nutrient sources to encourage growth after the first roots form. The optimum temperature for seed germina-tion for most peppers is 80-85oF, but the rate of germination may be erratic, taking from 8 to 25 days to emerge. Pepper seedlings are slower growing so make sure to water care-fully and evenly, as damping off disease can be a problem. Transplant to a 3-inch pot when the seedling has 2 sets of true leaves, and grow at approximately 70oF during the day and 60oF during the night. Remember to give them plenty of light. Stocky, strong transplants perform best and will give the highest yields. A light feeding of a diluted fer-tilizer solution will help overall plant vigor. Transplant outside after the soil has warmed up, a very important component for success-fully growing peppers! Generally plant them outside after the tomatoes. Unlike tomatoes, don’t bury pepper stems any deeper than the transplant soil line. Set the plants 12-18

inches apart in rows 24-30 inches apart. Direct sowing outdoors is not recommended.

Peppers are often planted in raised beds. This method improves soil drainage and al-lows access to the crop without causing soil compaction. Raised beds are typically 4-foot wide by any convenient length. Space plants 18 inches apart in both directions for wide row planting. Peppers grow best at temperatures of 70 to 80oF during the day and 65 to 70oF at night. Fruit set only occurs at temperatures of 75 to 85oF. Tempera-tures below 72oF or above 90oF will result in blossom drop and poor fruit set. As peppers have shallow root systems, cultivate care-fully or use ground mulches. Season extend-ers such as floating row covers and plastic mulch can prolong the growing season and are recommended for warm-season crops such as peppers. Plastic mulch should be black or the new photo-selective plastic that maximizes soil warming yet controls weeds. Row covers, if used, should be removed when temperatures inside the cover exceed 90oF for 2 or 3 consecutive days at mid af-ternoon, or for pollination.

Pepper flowers are self-pollinated by insects, although about 12% will cross with other plants. A mild variety can become hot be-cause of cross-pollination with a pungent cultivar. Pepper fruit may be borne on the plant pointing either up or down.

Irrigation It is very important to water carefully and evenly; when soil moisture is deficient blos-som end rot may occur; and under even

greater stress, fruit abortion is possible. For healthy and rapid growth, your plants need about an inch of water per week. The use of drip irrigation in conjunction with plastic mulch provides a more constant supply of water and results in better fruit quality and less blossom end rot.

Capsicum annum, and Capsicum frutescens Prehistoric remains in Peru show that pep-pers existed then, and they were cultivated in Central and South America in very early times. Columbus brought them to Europe in 1493, and they were quickly adopted and cul-tivated. In fact, it was the Europeans that gave peppers their name. The only pepper they had known until that time was the black and white spice we still sprinkle out of our peppershakers. When Columbus brought dried peppers back from the West Indies, Europeans said the fruit was "hotter than the pepper of the Caucasus," the familiar table

spice. The name ‘pepper’ stuck, and we've been using it ever since. In spite of sharing the same name, our table pepper and the sweet and hot peppers we grow are not re-lated. The black and white pepper we grind is the seed of the plant, Piper nigrum. Our home garden peppers belong to two species: Capsicum annuum (annual), which includes most of the varieties of bell, New Mexican, jalapeno, and wax peppers, and Capsicum frutescens (bushy), which includes the Ta-basco varieties.

MASTER GARDENERS

Compiled By John T. Kovatch

Diseases Fungal wilt and bacterial spot and speck are the most commonly encountered diseases. Common control measures include crop rotation, field sanitation, and fungicide applications. Many diseases can be eliminated or reduced by avoid-ing overhead watering. Where disease is a known problem, choose resistant varieties. Remove plant refuse and con-trol insect pests.

Fertility Peppers require high soil fertility early in the growing cycle. The plants must grow rapidly after being transplanted to pre-vent blooming and fruit set while they are too small. Fruit-setting on small plants stunts their growth. Apply two pound of a pre-plant fertilizer (10-10-10) for each 100 square feet. To reduce transplant

shock and promote rapid early growth, apply one cup of a liquid starter solution (15-30-15) at transplant time. One week after blossoming begins, side-dress with 2 tablespoon of 10-10-10 per plant. Soil pH should be maintained between 6.0 and 6.8

Pests Common insects that affect peppers include aphids, flea beetles and the European cornborer. Most insects and dis-eases that attack tomatoes will also affect peppers. For more information, consult University of Wisconsin - Extension publica-tion A2088, Managing Insects in the Home Vegetable Garden.

Harvest Most cultivars contain varying amounts of capsaicin, the chemical responsible for the heat, or pungency, of peppers. Cap-saicin is more concentrated in the seeds and internal walls where the seeds are attached. Removing these tissues can reduce the pungency of hot peppers. Peppers such as chili or cayenne can be dried on screen tables in a cool, dark, dry, well-ventilated area. Peppers can also be strung on thread through the stem and hung to dry. Dried peppers keep for up to 6 months at 60 to 70% relative humidity.

For maximum fruit production, harvest regularly. Pick when fruits are large, glossy, and thick-walled. Green peppers can be harvested 60 to 70 days from date of transplant. Allow another 3 weeks for coloring. Peppers are generally fully ripe and have the most flavor and vitamins when they turn red, yellow, purple, or or-ange. Fruit set after late August will not usually fully develop or ripen. Expect 5 to 10 large bell peppers and 20 to 50 hot peppers per plant. Peppers can be stored for up to 2 weeks at 45 to 50oF with 90 to 95% relative humidity.

Cultivar Selection If you cut open a pepper crosswise near the stem, you'll notice thin walls that di-vide the pepper into sections. These sec-tions are called the lobes, or cells. Most seed companies describe a well-shaped sweet bell pepper as being "blocky." The blocky shape comes from this division of the pepper into lobes, and a good, blocky pepper will have three or four lobes. The shape of blocky peppers makes them great for stuffing, slicing into pepper rings and general all-around use. Bell pep-pers, commonly measuring 3 inches wide by 4 inches long, usually have 3 to 4 lobes and a blocky appearance. Green

bell peppers can be left to turn red or yel-low when fully ripe. Most peppers are classified according to their degree of hot or mild flavor. The Scoville Heat Unit is a measure of pepper pungency and is shown for various varieties in seed cata-logs. Habanero type peppers are the hottest. The units will vary for each type of pepper based on variety, maturity, and whether the pepper is fresh or dried. Typically, pungent peppers require hot, dry conditions to fully develop their flavor and may not produce a suitable harvest in cool, wet summers.

Providing university research-based horticulture information and educational opportunities

Milwaukee County UW-Extension 932 South 60th Street

West Allis, WI 53214-3346 Phone: (414) 290-2400

Fax: (414) 290-2424 http://milwaukee.uwex.edu

Ozaukee County UW-Extension Box 994

121 West Main Street Port Washington, WI 53074

Phone: (262) 284-8288 http://www.co.ozaukee.wi.us

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