Bell Pepper

A bell pepper is the fruit of Capsicum annuum, a short, shrubby plant from the tropical Americas and a close relative of the tomato and the potato. In its home climate it is a perennial that flowers and fruits for several years. Gardeners grow it as an annual because frost ends it, and because a plant that must finish in one season still behaves like one that is in no hurry: peppers grow slower than tomatoes, take longer to ripen, and never run ahead of the weather the way a squash does.

The bell is the mild, thick-walled end of the species, bred for large hollow fruit with little or no capsaicin, the compound that makes chiles hot. That blocky, lobed shape is what you are waiting for when you count days to maturity: a plant usually shows its first flower within a month or two of transplanting, the fruit swells to full size in four to six weeks, and the color change that follows takes another two to four weeks on top.

Peppers want heat that a spring garden rarely has on schedule. Set transplants out only when night temperatures reliably stay above 55°F and soil is at least 65°F, which in most cold-winter regions is one to three weeks after the last frost date, later than you would plant tomatoes. A chilled pepper stops taking up phosphorus, may drop its first flowers and can stay permanently stunted, so the safe move is to wait, or to warm the bed first with black plastic or a fabric mulch for a week or two before planting day.

Start seed indoors eight to ten weeks before that warm planting date, not six: peppers germinate slowly, in two to three weeks, and only well. Sow in cell packs or plugs, keep the mix at 75-85°F with a heat mat, and expect leggy, top-heavy seedlings if light is weak. Transplant at the depth of the root ball rather than buried deep like a tomato, firm the soil around the roots and water the hole as you fill it.

Six to eight hours of direct sun is the working target, and peppers are unusually tolerant of the same brutal heat that ruins lettuce: fruit colors best in full sun. Above roughly 95°F, though, pollen goes poor and the plant starts dropping blossoms, so in hot climates a location with light afternoon shade can finish the season ahead of a fully exposed one that stalls in July and August.

Soil matters more here than in most crops because pepper roots are shallow, fine and easily drowned or dried. Aim for loose, well-drained ground heavy with organic matter, at pH 6.0 to 6.8; a spring soil test is worth reading before you add anything, since peppers are sensitive to both acidity and salt build-up. Then hold the moisture steady. One to two inches of water a week at the base, deep and regular rather than daily sprinkling, prevents most of the disorders that follow. Mulch the moment the soil is warm.

Feed lightly and early. Work balanced compost or a low-number fertilizer into the bed before planting, then wait until the first fruits have set and sized before sidedressing, at which point a moderate nitrogen feed with real calcium in it, such as a blend or a top-dressing of compost, supports the next truss without buying only leaves. Too much nitrogen is the classic pepper mistake: a big green bush with three fruit on it. Stop feeding in late summer so the plant puts its last energy into ripening what it carries.

Support and pruning are judgment calls. Blocky fruit on a compact plant can snap branches in wind, so a small cage or a single stake with a loose tie pays off in open sites. Pinching off the first flower, the one at the first fork, is optional but common: it costs you one early pepper and often buys a sturdier plant that carries more later. Strip lower leaves and any fruiting branches below the fork to keep soil splash off the foliage.

A full-size green bell is already a mature fruit that has simply not ripened further, and picking it at that stage tells the plant to invest in the next set, so an early harvest of green fruit raises total yield. Wait for color if flavor and nutrition are the goal. The change from green to red, yellow, orange, purple or chocolate adds sugars, softens the grassy edge and multiplies vitamin C and beta-carotene, which is why a vine-ripened red pepper tastes like something different entirely.

Cut the fruit rather than pulling it. A pepper is heavier than its stem prefers to tear, and yanking one usually snaps a branch or uproots a shallow plant; use pruning snips and leave a short stem stub. Pick in the morning after the dew dries, when fruit is firm and crisp, and check every two or three days in the flush, because overripe peppers go soft and thin-walled and the plant slows down.

Blossom drop is the complaint that sends gardeners looking for a pest when the culprit is the thermometer. Nights below 55°F or above 75°F, and daytime heat past 90°F with dry or saturated air, all stop pollination, and the plant aborts the flowers. Nothing sprays that better; shade cloth, even moisture and waiting for the weather window do. Fruit set resumes on its own once conditions pass.

The rest of the trouble list is mostly culture and weather. A sunken, dry, leathery patch at the blossom end is blossom-end rot, the same calcium-transport failure that hits tomatoes, and the fix is steadier watering rather than more lime dumped on mid-season. Pale, whitish, papery patches on the fruit side facing the sun are sunscald, common after heavy pruning or leaf loss. Bitter, rubbery peppers usually mean the fruit was harvested too early, that the plant was heat-stressed, or that the variety was cross-pollinated by a hot chile.