Picking each crop at its peak of freshness and flavour is key to a successful harvest. In this article, we’ll discuss the best time to harvest each kind of vegetable.
Broccoli: Harvest the main head before buds start to open and yellow flowers appear. Leave the plant, as side shoots will develop for later harvesting
Brussels sprouts are tastiest after they’ve been “kissed” by a frost. Harvest sprouts from the ground up over the course of several weeks.
Cabbage: Cut the head once it’s firm. Don’t wait too long or heads may split.
Cauliflower: Harvest before the temperature goes below 25°F (‐4°C), when the head is about 6‐8″ (15‐24 cm) in diameter, before the curd becomes granular or “ricey”.
Corn: Harvest corn after silks turn brown. Kernels should be fully‐formed and ooze a milky liquid when pierced (except for super‐sweet varieties in which the liquid remains clear).
Cucumbers: Slicing cucumbers are usually harvested when they’re about 6 inches (15 cm) long. Pickling cukes can be harvested when they’re small or medium‐sized (to pickle whole), or when they’re larger (to cut into spears or slices).
Summer Squash: Zucchini (courgettes) are best harvested when they’re 6‐10 inches (15‐25 cm) long, yellow crookneck when they’re 5‐7 inches (13‐18 cm) long.
Winter Squash and Pumpkins: Harvest before first frost when the fruit has a hard rind that resists being pierced with your fingernail. Leave two inches of the stem when cutting. Be careful not to break off the stem, which may cause the fruit to rot.
Head lettuces and romaine should be harvested when heads are firm.
Leaf lettuces, spinach, Swiss chard, mustard, kale, and collards may be harvested by cutting the whole plant or by using the cut‐and‐come‐again method, harvesting outer leaves as needed. (With kale, leave the center bud intact.) Picking a few leaves at a time, you can harvest earlier and pick only what you need. Harvesting the whole plant, however, produces a greater yield. Pick mustard, collards, and kale when leaves are smaller (and more tender). Harvest mesclun when leaves are young, and pull out whole plants if the bed becomes overcrowded. Mesclun and endive may resprout if cut an inch (2.5 cm) above the soil.
A light frost improves the flavour of endive, mustard greens, kale, and collards. Kale can even be harvested in the winter: cook the frozen leaves before they thaw out.
Peas: Harvest peas when they’re bright green. Light‐coloured or shriveled pods mean peas are past their prime. Harvest shell and snap peas when seeds are full and round, snow peas when seeds are flat. Pick daily to increase yield.
Beans: Pick shell beans when seeds are small and beans are slender; when seeds are large, beans are tough and stringy. Pick pole beans when they’re young so that the plant will keep producing. Harvest beans daily for a larger crop.
Tomatoes: Let tomatoes ripen on the vine until they’re totally red, without any green on their shoulders. They should snap off the vine with the slightest touch.
Peppers: Green peppers are immature fruit. If you pick a few green peppers from each plant, the plant will keep producing. You can keep harvesting for daily use as fruits mature to red (or other colour). Fully mature fruits are sweetest.
Eggplants (Aubergines): Harvest eggplants when their skins are glossy, from about 6″ (15 cm) long to maturity. A dull skin means the fruit is past its prime.
Radishes: Harvest early radishes frequently while they’re still small, usually less then an inch (2.5 cm) in diameter. Wait to harvest winter radishes until after a frost.
Carrots: Carrots can be harvested as soon as they reach a usable size.
Potatoes: Harvest new potatoes about two weeks after the potato plant blossoms. Carefully hand harvest and pull out no more than two potatoes per plant. Harvest mature potatoes several weeks after the plants have totally died back: this will toughen their skins and they’ll keep better. Harvest with a spading or potato fork. If you accidentally pierce a potato, use it immediately as the injury may cause it to rot. Let potatoes dry for a few hours before storing.
Onions: Let onions mature in the field. Allow green tops to turn brown and fall over before harvesting. Beets: Harvest beets from about 1 ½ to 4 inches (3.75‐10 cm), or up to maturity. Harvest beet greens at 4‐6″ (10‐15 cm) tall.
Turnips: Harvest turnips from about 2‐3 inches (5‐8 cm) up to maturity. Finish picking before hot summer weather. Harvest turnip greens throughout the season, leaving at least four leaves per plant for good root growth.
Rutabagas: Wait until a light frost to harvest rutabagas, but don’t subject them to a hard freeze unless covered by thick mulch.