If you like your food spicy, chili peppers are a garden necessity.


Hot pepper plants are small shrubs with striking red, orange, or yellow fruits, depending on the variety. These plants look great in a landscape and they can provide you with peppers all summer long.


Why the heat?

The reason chili peppers are hot is because they contain capsaicin. Capsaicin is found, in varying degrees, in nearly all peppers. Sweet bell peppers contain little to no capsaicin. Powerfully hot peppers are used in Africa to keep elephants out of gardens and other crops. Birds, on the other hand, do not have those particular pain receptors, so they are largely responsible for the spread of wild pepper plant seeds. Before we learn about different varieties of hot pepper and how to grow them, a word on Scoville heat units.

How to grow hot peppers

These plants need a long growing season to reach full flavor. Seeds are usually started 6 to 8 weeks before the weather is warm enough for them to be outside. Peppers need nighttime temperatures that are at least 50 to 55°F, to prevent blossom drop. Start with clean, disinfected pots that are 2 to 3 inches deep and that have drainage holes. You can disinfectant old containers by washing with a household cleaner, such as Lysol, and allowing them to air dry in the sun. This is an easy way to prevent future disease and pest problems. In the same vein, use new potting soil, rather than dirt from your garden. Seedlings are much more delicate than your mature plants, which may be strong enough to withstand existing pests or diseases. Also, use seed designated with a letter “V” - this indicates resistance to verticillium wilt.


Fill containers 3/4 full of moist, nutrient rich, organic potting soil. Seeds should be placed 1 inch apart and covered with 1/4-inch of soil or vermiculite. Wet the surface without disturbing or uncovering the seeds. You can use plastic food trays to hold your pots - the clear plastic covers make it easy to maintain moisture levels and the bases protect your furniture. Plastic wrap held in place with a rubber band can also be used. Once seeds germinate, remove the covers. Be sure to label your pots - popsicle sticks work well and they decompose in the garden later on.


Since chili plants are generally started when it is colder than their seeds like, you may want to invest in a seed heating mat. [Put aside the temptation to use that old heating pad - they get too hot, are not designed to handle moisture, and can be a fire hazard.] Sprouted seeds will need full sun or a grow light. Keep the soil moist, but not soggy.

Caring for seedlings

As the first set of true leaves emerge, thin plants to 2 inches apart or up-pot into larger containers. Water every other day, to avoid hydrophobic soil. Pick up your pots to make sure they feel heavy from the water. Check seedlings regularly for signs of aphids, mites, or snails. These pests can be hand-picked or wiped off with a wet paper towel. Continue to up-pot until outdoor temperatures are warm enough for your chili peppers.


Transplanting hot peppers

Prepare your seedlings to be transplanted by watering them to the point of run-off. Then, place one hand over the soil, with the plant stem between your fingers, and flip the pot upside down. You may need to jiggle or tap the pot to break the soil loose. If roots have really taken hold of the pot, use a sharp, clean knife to cut along the sides of the pot. Seedlings should be planted in a sunny location, 10 to 18 inches apart, depending on the variety. If watered regularly, chili peppers perform especially well in heat islands.


You can improve the plant’s root system by removing any growth from the bottom 1/3 of the stem and burying those nodes below the soil surface, the same way you might for tomatoes. These nodes will produce roots, giving your plant access to more water and nutrients. Water deeply, right away, to help the soil settle, removing air pockets, and keeping the roots moist. And be sure to label your plants! All peppers are self-pollinating, but crops are significantly larger when other pepper plants are nearby. Note: if you plan on saving seeds from your hot peppers, be sure to keep different varieties away from each other, as they will cross-pollinate.


Caring for hot pepper plants

Pepper plants benefit from a thick layer of organic mulch placed around, but not touching, each plant. Use a hose to water your plants thoroughly, at first. This will help the soil settle and keep the plants well hydrated. Once the roots take hold, you can use drip irrigation or a soaker hose. Plants should be side-dressed with nitrogen about once a month for healthy leaf growth. In August, you can increase feedings to once every two weeks. As fruit begins to mature, you can increase their hotness by only watering once a week and allowing the soil to dry out between waterings.

Harvesting hot peppers

Each pepper has a color that indicates it is ready to be picked. Read your seed packet or check online or at your local library to learn more about your specific varieties. Many peppers are harvested while immature, the flavor actually becomes sweeter as the fruits mature.


Pepper pests and diseases

Pepper weevils, cutworms, aphids, armyworms, flea beetles, leafminers, corn earworm, leafrollers, nematodes, weevils, thrips, spider mites, tomato psyllids, and whiteflies can all become pepper plant pests, though I have rarely had any serious problems here in the Bay Area. I have found that birds are more likely to become a problem. Most pepper diseases are of the fungal variety: powdery mildew, crown rot, root rot, verticillium wilt, and tomato spotted wilt are common with improper irrigation. Also bacterial spot, several mosaic viruses, blossom end rot, and curly top may occur. Sunburn, or sun scald, can also be a problem on pepper plants with insufficient leaf cover. Personally, I have had excellent results growing pepper plants under my fruit and nut trees.

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Make a little space in your spring planting schedule to start some chili pepper plants for yourself and your friends!

Sweet or hot, bell-shaped or elongate, all peppers are members of the nightshade family. 


​People have been growing peppers for several thousand years. Native to the Americas, peppers (Capsicum) are now grown all around the world. The popular spice, paprika, is made from several different types of peppers.

All peppers are self-pollinating, but crops are significantly larger when other pepper plants are nearby. ​​


Hot peppers and the Scoville scale

Hot peppers are rated using the Scoville scale.  Scoville heat units (SHU) are a function of the amount of capsaicin found in the fruit. For comparison, pepper spray used by law enforcement can have 500,000 to 1 million SHUs and sweet bell peppers have a Scoville rating of zero. Here are some common peppers and their Scoville ratings:

• Anaheim peppers- 1,000 to 3,500 SHUs 
• jalapeños - 3,500 to 10,000 SHUs
• Serrano peppers - 10,000 to 30,000 SHUs
• Cayenne pepper - 30,000 to 50,000 SHUs
• Habaneros and Scotch bonnets - 100,000 to 350,000 SHUs
• Carolina Reaper, Trinidad Scorpion, and Ghost peppers - 855,000 to 2,200,000 SHUs

Choose your pepper accordingly (and be sure to wash your hands after handling hot peppers and their seeds before you do ANYTHING else). Seriously. ​

How to grow peppers

Peppers love warm weather. In fact, there’s no sense starting pepper seeds early, because they won’t germinate. Even if they do, they won’t grow well. To get a head start on the growing season, many gardeners use seed heating mats. The soil needs to be 70 to 84 °F for peppers to really get going. Peppers prefer loose, loamy soil (or even sand), so you may want to grow them in raised beds or containers. Seeds should be planted 1/4 inch deep. Ultimately, you will want to place plants 18 to 24 inches apart. When thinning, snip unwanted plants off at soil level to avoid disturbing other plants’ roots. At first, the soil should be kept moist but not soggy. Soggy soil can cause damping-off disease and several other problems.

One of the most common mistakes gardeners make when harvesting peppers is that they do it too soon. If your peppers feel thin-skinned, give them some more time. ​

We’ve all heard some seeds or plants described as heirlooms and others hybrids, but what do those terms really mean?


Both hybrids and heirlooms come about through naturally occurring cross-pollination, as opposed to genetically modified organisms (GMOs), which are created in a lab using altered DNA strands.


Pre-industrial agriculture

Before agriculture became an industry, people grow a wider variety of plants for food. That biodiversity helped offset inclement weather, diseases and pests, and other threats to a failed crop and the resulting starvation. Corporate agriculture, on the other hand, feeds countless millions by generating a smaller variety of uniform plants that consistently grow at specific rates, that can be sprayed with a variety of pesticides, herbicides, and fungicides, ship well, and store well. As many of you know, taste and texture often suffer s a result. ​

Pros & cons of heirlooms

Heirloom seeds are those that have been handed down, person to person, in a specific geographical region, for a very long time. Also, heirlooms are open-pollinated, which means pollination occurs naturally, by wind, birds, animals, and insects, and not by human efforts. Heirloom varieties are at least 50 years old (some say 100 years), and many of them have been grown consistently, in the same locale, since before WWII. These plants have evolved to take advantage of local microclimates and beneficial insects. Heirloom seeds are hand selected by gardeners from the very best plants each growing season.  Many heirloom plants do not have the uniformity or long term storage capabilities of hybrids, but growers (myself included) claim that the flavor is significantly better. Heirloom crops have more variety in size and shape than hybrids, but they always grow true to their parent plants. Heirlooms are more genetically diverse, making them more durable as a species, and less susceptible to local pests and diseases. Heirloom offspring are fertile and can reproduce.


Pros & cons of hybrids

Hybrid plants are intentionally created by cross-pollinating different varieties of a species. The intention of hybridization is to take advantage of the best characteristics of each parent plant, creating what is known as hybrid vigor (heterosis). This vigor only lasts for one generation. Hybrid seeds do not grow true to their parents and they lack vigor and genetic diversity. This lack of diversity is what caused the Irish Potato Famine of the 1840s. If all the plants are identical, they are equally susceptible to pests and diseases. A single threat can be devastating.


Creating a hybrid that grows “true” to the desired characteristics takes years of diligent effort. Plants are often pollinated by hand or grown in greenhouses or pollination bags that block contamination from outside pollen to ensure that pollination only occurs between the desired plants. The majority of the fruits and vegetables you see in grocery stores are hybrids. Harvests are very consistent in size and shape. Hybridization is done for many specific characteristics:

• improved disease resistance
• easier growing
• early maturity
• better flavor
• bigger size
• longer storage capabilities

When shopping for plants and seeds, one way to know if it is a hybrid is to look at the Latin name. If you see the letter “x” between words in the name, it is a hybrid. For example:

Raspberry (Rubus idaeus) crossed with blackberry (Rubus ursinus)
  creates Loganberry (Rubus x loganobaccus)

*Check labels for the letters V, F, N, T or A. These symbols indicate a resistance to verticillium wilt, fusarium wilt, nematodes, tobacco mosaic virus or alternaria stem canker, respectively.

Understanding the difference between heirlooms and hybrids can help you make the right choice if you want to collect viable seeds from your harvest for next year’s planting.