A few crops are ready for harvest in three to four weeks from the time you sow the seeds. Radishes and the peppery salad green called curly cress are ready in a couple of weeks. But more often, plantings from seed take 7 to 12 weeks or more to mature. Check the seed packet or seed catalog for the time to harvest. However, the time given assumes ideal conditions; use it as a guide only.
When to Wait
How do you know when a plant is ready to be harvested? Baby snap beans, just 4 or 5 inches long, are absolutely delicious, although it takes a lot of them to make a suitable serving. There is a day when closely watched pea pods begin to show the swelling of young peas inside and you have gourmet petits pois. Like many other vegetables, they go from too young to just perfect to past perfect in a few days.
Some vegetables taste best when picked slightly overripe, but the moment of perfection is fleeting. A fully ripe sun-warmed tomato just off the vine may be too soft to travel well, but it tastes like heaven when dressed with a touch of extra-virgin olive oil and shreds of basil. A day or two later, it is too soft to cut without mashing.
Root crops are different—they wait for you. Winter carrots left in the row until close to frost time, such as the last sowings of late-season carrots, have a rich, sweet flavor not present in young carrots nor those planted for spring harvest. Parsnips are in a class of their own. They are crisp and sweet and taste best dug after the first frost. In New England, they stay in the ground all winter and are delicious harvested in spring. Turnips, however, grow bitter as they get older. Spring radishes that are not picked become coarse and overly hot. (However, daikon and other late radishes can stay in their rows longer without losing flavor.)
When to Use at Once
Most vegetables taste best eaten immediately after they have been harvested. The vegetable that most rapidly converts its sugars to starch is corn. There was a time when true aficionados of corn would start the water boiling before they picked the ears and then run all the way from the corn row back to the stove, shucking as they went. We now have corn varieties that convert their sugars more slowly. But it is still a fact that vegetables that stand at 70 degrees—room temperature—over a 24-hour period lose up to 50 percent of their vitamin C.
When they are refrigerated at 43 degrees, the loss is about 10 percent over a 10-day period. So, if you harvest before you can use the crops, get them into the refrigerator as quickly as possible. (This is true only for fully ripe produce. If you pick vegetables early, they ripen best at room temperature out of direct sunlight.)
When certain vegetables get into full production, they must be harvested regularly. In a day or two, the delicious little 6-inch cucumbers and zucchini become big, coarse vegetables full of seeds.
Lettuce bolts—goes to seed—especially as summer approaches. If you neglect to pick the perfect little peas, they are no better than frozen peas. Worse, the plants stop producing. A plant that is putting its energies into maturing huge vegetables is not working at producing little new vegetables. Picking garden produce is akin to deadheading flowers—to keep the crops coming, you have to keep them picked, and the earlier the better.
One of the profound pleasures a food garden offers is the daily walk along the rows to see what is happening where, what wonderful things are ready now, and what will be ready tomorrow. Keeping a log of the momentous events, the first harvests of peas in spring or the first salads from your own lettuce, is very helpful when planning next year’s garden.
Some vegetables must be picked as soon as they are ripe. Check these crops for ripe produce at least every two days. Other crops can wait a while; check them once a week. The third category will wait for weeks for you after they have matured. Harvest them when you’re ready.
Crops That Can’t Wait
Crops That Can Wait a Few Days
Lettuce and other greens
Crops That Can Wait a Few Weeks
Beets and other root vegetables