By Dr. Mercola
Bell peppers and chili peppers are common staples that add flavor and color to your meals. They're also easy to grow, even in small spaces. The heat of peppers is measured in Scoville heat units. A green pepper scores a zero on the scale, jalapeño peppers earn around 2,500 to 4,000 and Mexican habaneros, 200,000 to 500,000 units.
There are many different types of peppers, from sweet to flaming hot, making more than one variety useful in a single dish, adding complexity to the flavors. Popular pepper varieties include bell, Chile, banana, Hungarian, cayenne, jalapeno, Serrano, habañeros and others.
Below, I'll summarize growing tips for bell peppers1,2,3 and hot chili peppers,4,5 both of which are useful additions to a well-stocked home garden. I personally grow red bell peppers, habaneros and Thai chili peppers and love them all.
Uses and Medicinal Value of Peppers
Sweet and mild-tasting bell peppers can be sautéed with onions or diced into salads, soups and casseroles; stuffed, grilled, placed on sandwiches, or eaten raw for a fresh snack. Green, red and yellow bell peppers all contain phenolic compounds, ascorbic acid, carotenoids and free radical scavenging activity.
Green peppers have the highest phenolic activity but lower carotenoid content than the red and yellow varieties. Red peppers have the highest ascorbic acid (vitamin C) and a higher level of free radical scavenging activity. The active ingredient in hot chili peppers is capsaicin, which is what makes your mouth burn and gives the peppers their pungent odor. The smaller the pepper the hotter it tends to be.
The endorphin rush capsaicin triggers makes this compound an effective remedy for pain and other medical conditions. Research also suggests it helps shrink fat tissue,6 inhibits the growth of breast cancer cells,7 and may even reduce your risk of Parkinson's disease by nearly 20 percent when eaten regularly. Chili peppers also contain other beneficial bioactive plant compounds, including:8,9
- Capsanthin. This is the primary carotenoid (antioxidant) in red chili peppers, giving them their red color and typically accounting for up to 50 percent of the spice's antioxidant content
- Lutein. Most plentiful in immature (green) chili peppers, it has been shown to help maintain and improve eye health10
- Violaxanthin. It is the main carotenoid found in yellow chili peppers, which accounts for 37 to 68 percent of their total content
- Sinapic acid. Also known as sinapinic acid, this antioxidant is known for its neuroprotective potential11
- Ferulic acid. This compound has shown promise in protecting against diabetes, cancer and cardiovascular diseases12
Growing Bell Peppers: Preparation
Whether you're growing bell peppers from seed or using store-bought seedlings, begin by selecting and preparing the site. Peppers need lots of sun and grow best in deep, loamy, well-drained soil where peppers have not previously been grown, so move them around your garden if growing several years in a row.
Add about 1 inch of compost to the soil, but avoid adding too much nitrogen, as this can cause excessively rapid growth, making the plants larger and bushier but less productive and more prone to disease.
If growing from seed, start the seeds indoors eight to 10 weeks before your last frost date. You can find frost dates for your local area by checking The Old Farmer's Almanac, which is available online.13 Soak the seeds in lukewarm water for a few hours and keep the seed tray in a warm spot to encourage germination.
Before you transplant your seedlings into your garden, gradually expose them to outdoor conditions. By reducing stress, the plants will become larger and more productive.
Begin by placing them in an area sheltered from high wind and excessive sun exposure for a few hours a day for three or four days once daytime temperatures are consistently in the mid-60s. Over the following week, slowly increase the number of hours you leave them outdoors.
Pepper plants grow best in warm soil, so if the garden bed is still cool, warm the soil by placing a dark landscape paper over the area. Also make sure all threat of frost is over and nighttime temperatures are above 60 F before planting them in the ground.
Growing Bell Peppers: Transplanting and Harvesting
Space the plants 12 to 16 inches apart and stake taller varieties to protect the stems from breaking as they grow. If planting several varieties, separate them by at least 500 feet to prevent cross-pollination. Also keep them separate from other plants in the nightshade family, such as tomatoes and eggplants.
Water frequently, giving the plants at least 1 inch of water per week, or up to 1 gallon per day during hot, dry weather. Adding mulch will help retain moisture and normalize the soil temperature. Just remember they do like warm soil, so if temperatures are on the low end, mulching can actually make the soil too cool, which will stunt growth.
If daytime temperatures are below the mid-80s you may also want to consider a covered dome to retain heat. Should the weather get too hot, on the other hand, you may need to provide some shade to protect the fruit from sun scald. Staking up a piece of shade cloth should be sufficient.
Planting them 12 to 16 inches apart will also allow the leaves of the plants to touch, creating a natural canopy to protect the fruit from excessive sun exposure.
As the plant grows and begins to bloom, pinch off the first early blossoms. While this may sound counterintuitive at first, doing this will redirect the energy toward growth, allowing you to get more and larger fruits later. Leaving these early blossoms on will result in just a few small, early fruits.
Once the plant starts bearing fruit, side dress with organic fertilizer. Phosphorous is needed for fruit production while too much nitrogen will cause the plant to grow too fast and produce less fruit, so make sure your fertilizer has more phosphorous than nitrogen. Once the bell pepper has matured on the vine and is turning its designated color (whether yellow, red, green or purple), harvest your peppers by cutting them off with hand pruners.
Yanking them off by hand can damage the plant. While they can be harvested at an immature stage and allowed to ripen on your counter, allowing them to fully ripen on the vine will improve the flavor.
Growing Chili Peppers 101
Growing chili peppers takes about six months so you should plant them by May, although starting early is recommended so the plant will ripen just in time for summer. Here's a simple step-by-step guide for growing chilies:
- Fill a multi-cell seed tray with rich organic soil. Gently tamp it down and moisten with water. Place a seed in each cell, then lightly cover with a thin layer of soil. Water gently using a fine mist spray, then cover with cling wrap and store in a warm area of your home. The soil should be moist but not soaked.
- After two to four weeks, at the first sign of growth, move the seedlings to a warm, well-lit place, but out of direct sunlight. Water the plant from below to strengthen the roots, and check daily to ensure the surface is moist.
- Once the seedlings sprout a second set of leaves, transplant into 2- or 3-inch pots with moist soil and use liquid tomato as a weekly feeding.
- When the plants reach a height of 4 to 5 inches, transplant into larger pots, and stake the plants once they're 7 or 8 inches tall.
- Once the plants are about 12 inches tall, pinch off the tips right above the fifth set of leaves to encourage bushiness. Transplant to a larger pot if needed and make sure to check the plant daily for aphids. (If aphids are present, follow the instructions provided in the section below.)
- When flowers appear, gently dab a cotton swab into each flower to pollinate.
- Cut off the first chilies while still green to encourage fruiting all season long (July to October).
How to Address Aphids
Aphids are typically found in the folds between leaves. Simply spraying them off with cool water can help. Ladybugs and syrphid fly larvae14 (also known as hover flies or flower flies; often mistaken for bees and wasps) are natural predators that can quickly suppress an aphids infestation. You can tell you have active syrphid fly populations in your garden if you see black oily smears on plant foliage. This is the excrement of the larvae.
If you don't have an active syrphid fly population, you can buy live ladybugs (available online) and apply them to your garden.15 Before releasing them, refrigerate the live ladybugs for 30 minutes. It's best to release them in the evening, so be sure to time it properly. Spray some water on the lower portion of the area infected with aphids, then sprinkle the chilled ladybugs on the lower half of the plant.
The chilling will slow the ladybug's metabolism, basically putting them to sleep for the night. As the sun warms them up in the morning, they'll start scavenging for food and laying eggs. So, even though many will fly away, the eggs will hatch larvae that continue feeding on the aphids, and the grown ladybugs will continue the lifecycle of laying eggs and controlling pests in your garden.