Many experienced gardeners have been growing vegetables for so long they seem to develop a sixth sense as to when their vegetables are ready to pick and many would have a hard time explaining to a novice gardener what to look for. But if you are growing vegetables for the first time, knowing when to harvest is not nearly that obvious.
First, you should realize we harvest many of our vegetables before they reach full maturity. That may seem odd, but that’s the case with many of them: summer squash, peas, lettuce, beans, corn, and several others. So don’t keep on waiting in the hopes they’ll get bigger or become sweeter. Most vegetables go downhill pretty quickly once they’re past their prime, so when it’s time to harvest them, get to it!
What follows is a list of common vegetables and what to look for when you are harvesting them. However, I do one trick you could apply with pretty good success: the “farmer’s market test”! When any vegetable is the size, shape and texture you used to seeing in a farmer’s market, it’s pretty much ready to pick.
When to Harvest
Here are some handy tips on when to harvest common vegetables.
Beans: Harvest snap beans when the pods are immature, about 3 inches (7,5 cm) long, while the seeds are still small. The pod should be firm and crisp. If you wait too long, the pod becomes stringy and seeds turn pasty. Bush beans tend to produce their entire crop at about the same time. Home gardeners eventually learn that pole beans are more productive, because they produce over and over until then fall… as long as you harvest the pods regularly. If you let any pods mature, they’ll stop producing.
Beets: You can start to harvest the thinnings early in the season, because beet leaves are edible. Roots start to swell after a few weeks and you can usually harvest baby beets in about 40 to 50 days, when they are about 1 ½ to 2 inches (4 to 5 cm) in diameter; mature ones at about 70 days or more at 3 inches (7,5 cm). Usually when you see the top of the root protruding from the ground, it’s ready. If you leave beets too long, they don’t become much bigger, but instead turn fibrous and not as tasty.
Broccoli: When the buds are still very dense and green. If you harvest only the central stem, not the entire plant, it will likely produce a second harvest less abundant than the first one.
Brussels sprouts: When the sprouts are approximately 1½ inches (4 cm) in diameter, usually at the end of summer.
Cabbages: Harvest summer cabbage when the head reaches the desired size and is firm to the touch. Don’t wait too long, or it can split open. It you don’t cut it quite to the ground, it will produce a second crop with smaller heads, like Brussels sprouts. Harvest winter cabbage at about the time of the first frosts. A bit of cold weather and even frost will improve its taste.
Carrots: Harvest them at any time from mid-summer until the soil freezes. Early harvests will give you baby carrots, later ones, full-size ones.
Cauliflower: As soon as heads are white and firm. Note that homegrown cauliflower heads are rarely as big as farm-grown ones.
Celery: There are different schools of thought here. Personally, I look at celery as a summer-long supplier of leafy greens and harvest the outer leaves of the rosette leaves as I need them. (Even small leaves have great celery flavor; it isn’t just the thick petioles you can use in cooking.) The more traditional method is to harvest when the plant is dense and tall, in late summer or early fall. It will take light frosts, but avoid severe ones.
Corn: When the silks have turned brown and the ear feels plump, it’s time. Don’t pull the guard leaves down to check, you’ll only damage the ear. Sugar level drops rapidly on corn once it is harvested, so for a particularly tasty meal, starting boiling the water before you harvest!
Cucumbers: When they reach “farmer’s market” size. It you leave them too long on the plant, they will turn yellow and become bitter.
Eggplants: When the fruit has taken on its final color and is still glossy. Dull skin means it is too mature. Don’t wait for it to get bigger: most garden varieties are smaller than store-bought eggplants.
Garlic: Late July or early August, when the foliage begins to yellow.
Ground Cherries: When the outer husk turns tan and papery and the fruit easily detaches from the plant. It’s important to wait until the fruit has reached its final color (yellow or orange): immature fruits (green) are slightly toxic.
Jerusalem Artichokes: Harvest the tuberous roots in the fall, after a few frosts. Or in the early spring when the soil has thawed.
Kale: Harvest the outer leaves as needed throughout the summer. Harvest the entire plant for storage after a frost or two, as a bit of frost improves the taste.
Leeks: In the fall, after one or two good frosts or very early in the spring (leeks overwinter well).
Lettuce: Harvest the outer leaves as needed. Collect the whole plant when the head is well-formed but not hard. When you start to see a flower stem rise from the center of the plant (when it “goes to seed”), it’s too late: the leaves will be bitter and inedible. Usually a plant or two in the row will start first, a sign you should harvest the others without delay. You can however sow lettuce again and again, every two weeks, all summer until September. So as soon as one crop has been harvested, sow another.
Melons: The fruit is ripe when it turns a bit yellow and readily slips off its stalk. Watermelon is a bit different and its maturity can be hard to judge. One tip: when the tendril nearest the fruit turns brown and the fruit sounds hollow when you tap on it, it’s probably ready.
Onions: You can harvest onions at any time for use as green onions. For bulbs, especially if you want to store them, wait until the leaves start to turn yellow and begin to fall over. That means the onion is mature and ready for harvest. For better storage, dig up the bulbs, but leave them out to dry in the sun a few days before bringing them indoors
Peas: Harvest sugar snap peas (eaten with the pod) when the pod is still thin and the peas are barely developed. For garden peas (where the pea alone is eaten), wait until the pods are plump but the peas inside are still tender. Once the harvest begins, you’ll need to harvest every few days.
Peppers: Harvest sweet peppers, including bell peppers, when they are firm and full size, but still green. Or wait until they mature to their final color (red, yellow, orange, purple, etc.). Mature peppers are milder in taste and easier to digest. Harvest chili peppers towards the end of summer, when the fruit reaches its final color (usually red). However, some hot peppers are traditionally harvested when they have reached their full size, but are still green (the jalapeño, for example).
Potatoes: The main harvest comes when the foliage starts to die back, a sign the tubers are mature. However, harvest new potatoes about a week after the plant begins to bloom. Harvest only as many new potatoes as you need immediately, as they don’t store well.
Radishes: Harvest spring/summer radishes about 3-6 weeks after sowing, when the root is still fairly small. Left in the ground too long, it becomes fibrous and bitter and the plant will go to seed. You can resow radishes throughout the summer until September to ensure you’ll always have fresh radishes on hand. The foliage is also edible. Winter radishes and daikons are storage radishes and slower to mature. They are harvested in the fall and can tolerate light frosts.
Rutabagas (Swede Turnip): In the fall, preferably after a frost, because the cold gives the root a sweeter flavor. Not to be confused with turnips (see below).
Spinach: You have to harvest early, within 40 to 60 days of sowing. You can harvest the outer leaves first, but when the plant begins to grow in height, that means it is about to go to seed, so harvest without delay or it will no longer be edible.
Summer squash (zucchini, patty pan, etc.): While the fruit is still young and firm with a thin skin and certainly before seeds start to form. Once summer squashes start producing, you’ll have to check the plant every other day, as they just keep coming! Don’t let the fruits get too big or their taste deteriorates. In the case of zucchini, for example, ideally you’d harvest it before it reaches 10 inches (25 cm) in length. With summer squashes, the more you harvest, the more the plant produces!
Swiss Chard: Harvest the outer leaves as needed throughout the summer, leaving those in the center intact: that way the plant will continue to produce until frost. The leaves are edible at any stage, whether small or super-sized!
Tomatoes: Ideally, when the fruit has reached its final color (red, orange, yellow, purple, etc.) and is a bit soft when you press it. Determinate tomatoes are the earliest, but tend to all ripen at the same time. Indeterminate tomatoes (the taller ones) produce all summer, almost until frost. When frost threatens, collect the remaining fruit: those that have started to change color can still ripen; just put them in a dark pantry. Those that are still green can used in recipes calling for green tomatoes (ketchup, etc.).
Turnips: These are not the same vegetable as rutabagas (or Swede turnips): see above. Harvest when the root is about the size seen in a farmer’s market, that is about about 2 to 2 ½ inches (5 to 6 cm) in diameter. If left too long, the root will grow in size and becomes woodier, but remains edible.
Winter Squash (pumpkin, butternut squash, spaghetti squash, etc.): When the fruit is fully mature. Often the fruit changes color. If not, check the stalk: it will dry and softens as the fruit matures. They can take light frost.