Many vegetables will let you know when it’s time to bring them in by giving you clues. All you need to know is what they are:
Color. Most people understand to pick a tomato when it has reached the color that it is supposed to be—that’s easy. What you may not know is that winter squash will do the same thing, just developing their full color when ripe. They can take some frost as well, so if they’re not ready don’t rush it. Just be sure to get them in before a killing frost.
Size: Relatively Small. Snow and sugar peas, which you eat pod and all, should be picked before the seeds inside start to develop; likewise garden beans and wax beans. Kohlrabi should be harvested when it is about the size of a golf ball; any larger and they get woody, which ruins the flavor. Summer squash and cucumbers can be eaten when they are bigger, but squash tastes better when it’s young and cucumbers have a tendency to get seedy later in life.
Size: Relatively Big. The opposite is true for peas and beans that you will remove from the pod, to a point. For most, like shell peas and limas, go ahead and let them get plump. For fava beans, the same is almost true. After a point they can get woody as well. They would have to be pretty darn big, though.
Size: That Depends. Okra should be harvested no bigger than what the seed packet recommends. For most this is just a few inches, but some varieties grow larger. Cabbage can be harvested small (shown), or allowed to get bigger. If they get too big, they can split; still edible, but a little messier. Brussels sprouts are like cabbages, and can be enjoyed at any size, just don’t let them get so large they begin to open. Carrots will give you an indication of how big they are if you brush back a little soil from around the stem. Be careful though: carrots are great deceivers. Even though they may actually be smaller than they appear, they are most likely still edible.
Before They Bolt. Bolting is simply the term we use for when a plant produces flowers that we don’t want. What we harvest from broccoli and cauliflower are actually unopened flower heads, and that’s the way to harvest them. The same is true for basil and most salad greens; they are better brought in before they start making flowers.
When They Fall Down. Really, does it get any easier than an actual show of "we are ready"? Potatoes, onions and Jerusalem artichokes, aka sunchokes, will actually fall over when it’s time to harvest. Potatoes can be picked as ‘new’ potatoes as soon as you see flowers, but the stems falling over is an indication that the plants are done producing. Onions are most certainly done. Jerusalem artichokes can be harvested starting at this point, and continuing on even after a frost. Some say they actually taste better then.
Miscellaneous. Pick both hot and sweet peppers early to encourage more growth, then let them turn color as they mature, depending on the variety. Pick corn when the ears produce a milky substance from the kernels. This is about 3 weeks from when you first see the silks. Bring in all your sweet potatoes before the frost. Eggplants get shiny skins when they are ripe.
Melons are Difficult. Watermelons make a "thump" when you tap on them, and their skins turn color where it meets the ground. Not too bad. All other types of melon simply take practice to know when they are ripe. I guess they just don’t want to give their secrets away.
Gardening Jones is a master gardener in Pennsylvania. Learn more atgardeningjones.com/blog.
If you'd like to harvest seeds in addition to fruits and vegetables, try reading The Complete Guide to Saving Seeds. You'll be able to save seeds like a master and keep your garden growing into perpetuity.
Find delicious ways to use your homegrown vegetables in Recipes from a Kitchen Garden.
Make your harvest last longer with the advice in The Joy of Keeping a Root Cellar: The Ultimate Guide to Canning, Freezing, Drying, Smoking and Cellaring the Harvest.