Author: Extension Vegetable Specialist and Assistant Professor, Department of Extension Plant Sciences, New Mexico State University.
Asparagus—Cut or snap spears off at soil line when 6 to 10 inches long, before heads open. Cease harvesting when average spear diameter is less than 1/4 inch.
Beans (snap)—Full-sized pods, beans about 1/4 of their mature size, before constrictions in the pod are evident.
Beans (lima)—When well filled, but not overmature. Seeds should be green and tender.
Beets—Diameter of 1 1/2 to 2 inches. Harvest before hot weather in spring or moderate frost in fall. Tops used for greens should be tender.
Broccoli—When head is fully developed and tight and before flowers begin to open. Remove with sharp knife, leaving 4 to 6 inches of stem.
Brussels Sprouts—Mature from bottom up. Harvest sprouts when bright green, plump, and firm and before hard freeze occurs. Sprouts will taste sweeter if left on the plant until after mild frost.
Cabbage—Compact, firm head. Heads may burst and become unmarketable during hot weather.
Cabbage, Chinese (heading or pe tsai)—When heads are firm, removing outer leaves.
Cabbage, Chinese (non-heading or pak choy/bok choy)—Single leaves or complete plant.
Cantaloupe (muskmelon)—When stem separates easily from fruit (full slip). May also be harvested at half-slip stage (only half of stem slips cleanly off fruit when forced) for commercial shipping.
Carrots—Depending on variety, about 3/4 to 1 1/2 inches in diameter. In fall, harvest before moderate frost.
Cauliflower—Tie or break outer leaves over developing head (curd) when 1 to 2 inches in diameter to protect from sunlight (blanch). Check curds every 2 to 3 days and harvest when full sized, white, tight, and smooth (not ricey).
Chard (Swiss)—As leaves become large enough. Harvest continuously through summer until frost.
Collards (kale and mustard)—Young plants or lower leaves on older plants. Leaves should be young and tender. Taste improves with cool weather.
Corn (sweet)—When kernels are near full size and at the milk stage. Silks should be brown.
Cucumbers (pickling)—At desired size.
Cucumbers (slicing)—Before seeds become half-size. Varies with variety, but fruit should be 1 1/2 to 2 1/2 inches in diameter, 5 to 8 inches long, and should not yet have turned yellow.
Eggplant—Immature to less than full-grown, firm, and glossy black to purple in color (or as appropriate for the cultivar). Harvest before skin toughens and seeds become large.
Kohlrabi—Fleshy, swollen stem about 2 1/2 to 3 inches in diameter; before stem becomes woody.
Lettuce (head)—As heads become solid, yielding slightly to pressure.
Lettuce (leaf)—Whole plant before hot weather occurs. Outer leaves can also be removed to allow for multiple harvests.
Okra—Immature pods (3 to 4 inches long).
Onions (bulb)—Depending on variety, when about half the tops have weakened and fallen over and bulbs are at least 2 inches in diameter.
Onions (bunching)—Before bulbing starts or before they become too thick (over 1/2 inch diameter).
Parsnips—Can be harvested any time they have attained a desired size. Taste improves after exposure to several moderate freezes before being dug.
Peas (English)—Bright green, pods fully developed but still tender, and before seeds develop fully. Peas should be sweet when raw.
Peas (edible pod)—Harvest when pods fully developed, but before seeds are more than half full size.
Peppers (bell, sweet)—Fruit should be full size but still firm and crisp in texture. Harvest when green if green fruits are desired. If sweeter, more mature fruits are desired, leave on plant until red, yellow, orange, or purple color develops, according to variety.
Peppers (green chile)—Fruit should be full size, firm, and crisp when squeezed. Harvest when fruit are green or green with a slight amount of red color.
Peppers (red chile)—Fruit should be allowed to turn completely red and left on plant until partially to fully dried.
Potatoes (Irish)—Because tubers continue to grow until vines die, they should not be harvested until vines turn yellow or die. Tubers should be allowed to cure for a few days in a well-ventilated, shady place. For new potatoes, harvest at any early stage of development.
Potatoes (sweet)—Before freezing weather. Cure under warm conditions (80–85°F) for a week.
Pumpkins—Fruit should be fully colored with skins sufficiently hardened to resist denting with a fingernail. Harvest before a hard freeze.
Radishes—As soon as roots reach edible size.
Rhubarb—Delay harvest until second year after establishment. Established plantings (3 years) can be harvested for approximately 8 weeks. Harvest largest and best stalks by grasping each stalk near base and pulling slightly in one direction.
Spinach—Can be cut just below crown for once-over harvest, or above the growing point to allow regrowth. Older leaves can also be pinched off near the base of the plant to allow multiple harvests.
Squash (summer)—As immature fruit when young and tender. Fingernail should easily penetrate rind. Long-fruit varieties (zucchini) are harvested when 6 to 8 inches long, while scallops should be 3 to 4 inches in diameter.
Squash (winter)—Rind should be firm and glossy and resist denting with a fingernail. Portion of fruit that touches soil should be cream to orange in color when mature. Harvest before a heavy frost.
Tomatoes—At the pink stage or beyond, but while fruit is still firm.
Turnips—About 1 1/2 to 3 inches in diameter.
Watermelons—Tendril opposite fruit withers as fruit ripens; soil spot (where watermelon rests on soil) turns from white to creamy yellow; the rind at the soil spot becomes tough and resists denting with a fingernail; rapping or thumping produces a dull sound at maturity rather than a hollow sound.
Original authors: J.N. Corgan, Agricultural Experiment Station, and Esteban Herrera, former Extension Horticulture Specialist.
Stephanie Walker is Extension Vegetable Specialist, and has extensive experience in the food processing industry. Her primary research interests include genetics and breeding of chile peppers, vegetable mechanization, enhancing pigment content, post-harvest quality, and irrigation efficiency. She works to help commercial vegetable growers enhance the sustainability and profitability of their operations through collaboration, experimentation, and information sharing.
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Revised and electronically distributed in December 2010 Las Cruces, NM.