Starting seeds: Chile seeds germinate at soil temperatures of 75 - 90 Fahrenheit or 20 - 35 Celsius. The ideal temperature is 85 degrees Fahrenheit or 30 degrees Celsius. Those kind of temperatures are tough to achieve unassisted if you are starting your seeds indoors. The solution is to use a plant propagation mat, or at least keep your moistened seed in a warm place until it sprouts. A heating pad available at any drug or discount store may work just as well as more expensive plant propagation "systems." However, newer-style heating pads often shut off automatically after two hours, so try to find one without a shutoff timer.
No matter how you choose to germinate your seeds, cleanliness is very important. Wash your hands before you begin, and wash and sanitize any container you will use to germinate. If you do not do these things, the warm, moist environment necessary for germination will cause mold to go crazy.
Germination usually takes about 7 -10 days. Some chiles are slower to germinate than others. Some like to pre-soak slow to germinate varieties such as habaneros or Bhut Jolokia seeds, but I have never found soaking to make that much of a difference. If you want to pre-soak, soak for a minimum of four hours, but overnight is better, in a solution of 1 Teaspoon of Saltpeter (Potassium Nitrate) to one quart of water or 1 Teaspoon of 5% Chlorine Bleach in one quart of water. To give your seeds the best start possible, let water obtained from a public water system sit a day or two to allow chlorine to dissolve, or run it through a carbon filter. The water should also be boiled to sterilize it.
Plant the seeds in a moist, not wet sterile potting medium in pots or flats 1/4" - 1mm deep and ½" - 2mm apart and cover with plastic. If you want to use the paper-towel and bag method, soak your paper towel in water and squeeze out any excess water. Sprinkle your seeds onto the paper towel and then slide it into a zip-top bag. Keep them warm until they germinate. I have found that coffee filters actually work better than paper towels. Coffee filters have a tighter weave and the emerging roots will not grow into them. If you use paper towels, you may have to tear off a portion of the paper towel and plant it with the germinated seed.
You should start your seeds at least 8 and preferably 10 weeks before the last frost date for your area. Check the Plant Hardiness Zone Map if you are not sure. The map's zones represent average annual minimum temperature ranges. Most seed suppliers will list a zone on their package. This zone is the coldest zone in which the plant normally succeeds. The Plant "Cold" Hardiness Zone is an indicator, and should not be used as the sole source to determine whether a particular plant will survive in a specific location.
Once the seedlings are up, remove the plastic cover, but do not let the soil dry out. If you allow the seedlings to dry out, they may wilt or even die. If they dry out to the point of wilting, their growth may be stunted. Lighting is essential. Put the lights as close to the seedlings as possible, and raise the height as necessary. Many swear by expensive "grow lights," but ordinary florescent shop lights work just as well. The key is to burn the lights a sufficient amount of time to give the seedlings 12-16 hours of light per day. Timers are handy for these purposes.
Transplanting: Transplant when the second set of leaves form and grow to 3/8" to ½" wide. Transplant to jiffy pots, six packs or even to waxed milk cartons. Soil temperatures should be kept to a minimum of 70 degrees Fahrenheit for fastest growth.
Most good potting soils contain some nutrients, but a good, non-burning liquid high-phosphorous fertilizer can improve root growth. Apply according to package directions about once a week. Phosphorous is the middle number between Nitrogen and Potassium. A 15-30-15 fertilizer has twice as much Phosphorous as the other two elements.
Hardening Off and Setting Out: About two weeks prior to planting in the garden and one week before your last expected frost, begin hardening the plants by gradually increasing their exposure to sunlight and wind. Any good gardening book will explain more about this procedure. Before transplanting, be sure that the outdoor soil temperature is at least 55 degrees Fahrenheit. Lower temperatures increase transplant shock and may lead to blossom drop and leafy growth with little or no fruit. You can get a jump on the growing season by using raised beds, which have a higher soil temperature than surrounding soil, or by using water walls or some other type of plant cover. Such covers will protect against light frost, but make sure you remove them before sunny days to avoid cooking your tender, young plants.
When transplanting from containers, there will be some root damage which will slow the plants, so try to be as careful as possible. If you use jiffy pots, tear off the bottom but try not to disturb the roots. Dig the hole deeper than necessary and filling it with loose potting soil to encourage good root development. I have also heard that chiles like phosphorous, so throwing a paper matchbook down in the hole before planting can't hurt.
Pests: If cutworms are a problem in your area, a paper cup with the bottom cut out, placed around the stem about 1/2" into the ground should protect the stem. Fertilize with high quality, balanced fertilizer, such as 15-15-15.
Growing and Harvesting: Now that your chile plants are in the garden, make sure they get lots of sunshine, but keep them watered, fertilized, and protected from the wind. Keep a lookout for pests. The major chile pests are aphids, and they can build up rapidly. Organic controls such as liquid dish soap and water will help control aphids, or you can spray with a chemical such as diazinon® (Note, diazinon was banned in the United States effective December 31, 2004 - although you can still use any product you still have on hand if you follow label directions). Do not harvest chiles until the recommended days after spraying. The diazinon® label suggests five days for peppers.
Blossom Drop. You have worked so hard to get your plants germinated and growing, and wonder why your flower blossoms are dropping off and no pods are forming. There are many causes, among them:
1. Day temp too high (over 95 deg. F)
2. Night temp too low (below 65 deg. F)
3. Too much nitrogen fertilizer.
4. Too much water.
5. Not enough light. Low light levels reduces fertility).
6. It is too dry. Very low humidity reduces fertility.
7. Poor air circulation leading to a lack of pollination.
8. Lack of pollinating insects.
9. Pot is too small. Peppers do better in at least 5 gallon containers.
10. Too much mineral in feedwater.
11. Too much grower attention. Peppers are pretty tough on their own, and do not need much care.
When to pick? You can harvest your chiles when they are green. But mature chiles usually turn some other color when "ripe" and may develop prettier colors, different heat levels and different flavors if allowed to ripen before harvesting. Depending on the variety, mature chiles change from green to orange, red, yellow, brown, or some shade in-between. Some chiles (especially jalapeños) may turn black at some stage of their development.
Late season: As the growing season comes to a close, cover the plants at night if the temperature is predicted to go below 30 degrees Fahrenheit or -1 degrees Celsius. You will be surprised at how long you can extend the growing season. Plastic or old sheets work for covers. Remember to uncover the plants before the sun gets too high.
Diseases: If you have used or touched any form of tobacco, wash your hands thoroughly before handling plants or seeds. Tobacco products harbor the tobacco mosaic virus, which is deadly to peppers.
Saving Seeds: If you wish to save seeds, hang a couple of ripe chiles up in a dry place until thoroughly dry. Remove the seeds, and dry for a couple more weeks before saving them in a cool, dry place. Be advised that many chiles cross-pollinate, so the fruits resulting from saved seed may not be true to form. Also, if you are attempting to grow from a patented hybrid chile, the seed provider may have bred in a terminator gene to protect their patent. Saved seed may not have a germination rate as high as treated seeds, but the typical habanero pod has lots of them so you should have no shortage of seeds. The seeds should remain viable for 2 -5 years, depending on storage conditions.
Growing Indoors: Chiles are actually perennials which are usually grown outdoors as annuals. If your climate is mild enough, you can grow plants like trees and they will produce for several years. Although they may lose their leaves in low temperatures and low light conditions, they will bounce back when it warms up and the sunlight returns. For extensive help growing chiles, including disease information, canning, storing and other helpful information, turn to the masters at New Mexico State University's Chile Pepper Institute.
How hot is that chile?
The Scoville Heat Unit Scale (see chart) is a long-standing measure of the hotness of chile peppers. Capsaicin is a chemical compound that stimulates chemical receptor nerve endings in the skin. The number of Scoville heat units (SHU) indicates the amount of capsaicin present in a particular pepper. The scale was developed in 1912 by American chemist Wilbur Scoville, specifically to rate the pungency or heat of peppers. Officially, his method was known as the Scoville Organoleptic Test. With the original Scoville method, a solution of a pepper extract was diluted in sugar syrup until the heat is no longer detectable to a group of tasters. The amount of dilution (pepper & sugar syrup) provides a measure on the Scoville Scale. Therefore, a bell pepper or other sweet pepper - which contains no capsaicin - has a Scoville rating of zero, or no detectable heat, even when it's undiluted. On the other end of the spectrum, the hottest chiles, such as habanero and chiltepin peppers, have a rating of 200,000 or higher which indicates their extract has to be diluted 200,000 times before the capsaicin heat is undetectable. The shortfall of the Scoville test is that it relies on human perception which is certainly subjective.
Today, pepper and spice heat is now measured by a more scientific method known as High Performance Liquid Chromatography or HPLC. A mathematical formula is then applied to weigh peppers by their ability to create a sensation of heat. This method does not use Scoville Heat Units (SHU) but measures something called ASTA Pungency Units. In this process, one part of capsaicin per million translates to 15 Scoville units. This system says that ASTA Pungency Units can be multiplied by 15 to be reported as Scoville units, but the conversion is approximate. Leading spice and pepper experts say there is consensus that the ASTA units results in 20–40% lower heat than the Scoville method provides.
So which are the hottest? At the present time, here are the top ten:
1. Carolina Reaper (1,569,300)
2. Trinidad Scorpion Butch T (1,463,700)
3. Scorpion cultivars and Naga Viper Chilli (1,250,000 to 1,350,000)
4. Chocolate 7-pod(douglah) and Infinity Chilli (1,200,000 to 1,250,000)
5. 7-pod varieties; Barrackpore, primo, yellow, red (1,100,000 to 1,200,000)
6. The Nagas; Bhut Jolokia, Bih Jolokia, Naga Jolokia, Dorset Naga, Naga Morich (900,000 to 1,100,000)
7. Naga x Habanero crosses; Habanaga, Nagabon (800,000)
8. Red Savina Habanero (577,000)
9. Chocolate Habanero or Caribbean Habanero (250,000 to 350,000)
10. Habaneros and Scotch Bonnets (100,000 to 250,000)
Revised November 23, 2013