Wednesday, August 12, 2009

When to harvest?

At a community garden recently I was asked when eggplant was ready for harvest. It’s particularly tough to know when to pick vegetables you are growing for the first time and perhaps rarely eat.

Most fruiting and many leafy vegetables are not grown until maturity but are picked when sweet and tender. It’s really a balance between allowing more time to produce greater yield versus the best quality. In my mind, quality and flavor for fresh eating win out unless vegetables are being grown for drying (beans) or preservation.

For fruiting crops such as squash, peppers, eggplant, tomatillo and okra, keep in mind that you generally want to nab fruit before seeds fully form. Once seeds form the plant quits producing and the fruit structure begins to toughen or break down.

Cob and pod vegetables should be harvested before sugars are converted to starch. If corn is allowed to go too long by even a few days, fresh eating quality suffers dramatically. Pods of peas, beans and okra become fibrous and toughen. Asparagus should also be mentioned for developing fibers if not picked early.

The hardest thing for me to see is summer squash and cucumbers left to grow large (yellow straightnecks nearing overmaturity photo above). They should be cut young before seeds fully develop. This also keeps squash and cucumbers coming. Do allow winter (also called fall) squash to develop tough skins and seeds. Maturity also develops the flavor of the flesh. Yields will be reduced but this is the compromise with winter squash.

Unless you like green tomato dishes, tomatoes are best ripened to full color on the vine. Peppers picked green promotes more. When allowed to develop red color and seeds, production of more peppers slows. Eggplants can be harvested when only half their mature size and shiny. Dull skinned fruits often have turned bitter and woody (harvest soon in photo right). Tomatillo husks will change color from green to tan. Greener fruit has more tartness than fruit allowed to develop a yellow color.

Leafy salad greens can be harvested when leaves are small and tender. Once seedstalks begin to form, it’s too late as bitterness and toughness have already set in. While outer leaves of Swiss chard, looseleaf lettuce, spinach and kale can be removed in installments to promote more growth, this only works for so long.

Heading greens such as lettuce should have developed firm heads. Cabbage is best harvested loose in summer. Save development of firm heads for fall and winter cabbages (photo left).

Root vegetables can be harvested small (new potatoes and young beets) or allowed to grow to size. Do not allow to oversize and become woody (carrots, beets and turnips) particularly in summer. In fall these roots will keep longer in cool soil before harvest. Parsnips in fact develop better flavor when harvested after frost and store well in the garden.

Photo credits: squash, eggplant and cabbage - Carl Wilson


  1. Thanks for the tips on harvesting. I have an "ichibod" eggplant, and it has a dozen banana-sized fruit. I cut one yesterday just to see what it looked like inside, and it only had a few soft, white seeds. I think I'll start harvesting them now I know I need to do it before those seeds mature.

  2. So when should I pick corn? Last year we picked too soon and this year too late. :( I heard that the tassles should be brown but is the stalk still very green??

  3. Harvest when silks turn brown and dry. Shuck down a small amount of the husk and check kernels. They should ooze a milky liquid when pierced (except the super sweet types leak clear juice). Ears of the same variety generally ripen within a few days of each other so do check every day after silks turn brown.