Gardening: The wide world of peppers, from sweet to hot. We grow these perennials as annuals.

Experienced gardeners are dismayed at people on social media extolling bell peppers as the only sweet peppers. Those people apparently don’t know about the many tapered and wedge-shaped sweet peppers available, some used for roasting, others for stuffing and frying, and some for grinding into paprika.

The botanic genus name for “peppers,” both hot and sweet, is Capsicum, but we call these American natives “peppers” because Christopher Columbus was lost and thought he was in India. In Europe, sweet Capsicums are tapered, some wedged or horn-shaped, few of them bell-shaped. Asian peppers tend to be long and slim, some quite small, and hat-blowing hot. Bell peppers are most useful for stuffing, since a perfect one stands upright, but one can lay a half of a tapered pepper and stuff it before cooking, like the standing bell peppers.

Some Europeans call Capsicums “pimentos” (pimientos – note the extra i ) – the thick-fleshed small peppers we usually find canned in our grocery stores. South Americans call most of their Capsicums Ajis, while many of us use the Aztec term “chile.” The super-pungent chiles are Capsicum chinense (habaneros, for example), and even hotter is the Ghost pepper or Bhut jolokia, a short, tapered and wrinkled chile that will clear your sinuses — and perhaps other parts of your body.

Red or brown chiles are ripe, and green ones are not. Many people have digestive problems with unripe or green bell peppers, but those problems vanish when they eat ripe ones. There are other colors of some peppers, such as yellow, orange, purple and even black, most turning red when ripe. A complication in the chile world is the fact that the fresh pod has a different name than the dried version. For example, a poblano is fresh, but when it’s dried, it’s called ancho. If any pod is hot or pungent, that part that stings your eyes, mouth and other fragile membranes is called Capsaicin, and it’s concentrated in the placental wall and, to some extent, the seeds. Water or beer aren’t as effective in ameliorating the burn as milk or some oily substance.

Capsicum plants may range in size from about 6 inches (Prik y nu) to 4 or 5 feet for some of the C. baccatum Ajis, or even the South African “peppadews.” This size variation puts the gardener on notice when planning, for the tall versions easily shade out other garden plants. Another thing to think about when planning a garden is cross-pollination. Few of us can separate pepper plants by 500 feet, considered necessary to avoid cross-pollination, so I’d advise against saving your Capsicum seeds unless you grow only one variety or can bag blossoms.

Cross-pollination affects only seeds, not this year’s “meat” of peppers, so sweet peppers will still taste sweet unless your seed was contaminated. I once tried caging Capsicum plants, and thought I was successful until the day I saw tiny bees inside a cage and others squirming through soil to get under and inside the cage.

Seeds of chiles or peppers germinate slowly — the hot varieties slower than the sweet ones in my experience. To hasten germination of the hot varieties, you can soak seeds in a mix of one teaspoon of saltpeter (potassium nitrate) in a quart of water for two or more hours before planting. Seeds germinate more rapidly with bottom heat. I have my heat mat set for 80 degrees for chile germination.

When buying seeds, watch for estimates of pungence, calculated by the Scoville scale. Bell peppers have zero Scoville units, and Anaheims (common in cans with Ortega brand) up to 1,000. Some claim Poblanos are hotter than Anaheims, but I think they’re about the same. To contrast, jalapeños contain 2,500- 8,000 Scoville units, and the Bhut jolokia has 800,000 to a million Scoville units.

Some of the variation in heat is accounted for by the way a plant is grown. If it’s threatened by not quite enough or too much water, its fruit will be hotter than a well-watered plant. Any stress such as high temperatures, using stones for mulch near the plants or deficiency of nutrients may increase pungency, although the gardener may risk blossom end rot in the pods. Nitrogen applied after fruit set will lower the pungence.

Expert chile plant growers use the plant’s natural hormones to grow bushy plants by nipping off the top of the plant once it’s produced at least four true leaves. The bushier the plant, the more fruit or pods it will produce.

All chile or pepper plants are perennials, although in our area we grow them as annuals. You can dig them before autumn frost, pot them and bring them indoors. They may defoliate (drop their leaves), and if so, you should water less than they’re used to until they develop new leaves.

Spring Garden School

Gardeners, here’s your chance to green up your thumbs! The University of Idaho Master Gardeners and Edwards Greenhouse are co-sponsoring a “Spring into Spring” Garden School on Saturday, Feb. 8, at Edwards Greenhouse, 4106 Sand Creek, Boise.

The school will run from 9 a.m. to 1 p.m. The cost is $5 per person (no credit cards, cash or check only). Registration will begin at 8 a.m.

Many interesting gardening topics will be presented. For more information, contact the University of Idaho Master Gardeners at the Uof I Extension Office: (208) 287-5900 or (208) 287-5917.