Asparagus plants are usually not harvested for the first three years in order to allow the crowns to develop a strong root system. Asparagus spears are ready to harvest when they are about 6″-8″ tall. The tips should be tightly closed and the stalks should be firm but tender. Only use spears thicker than a pencil; let anything smaller than that grow into ferns. The harvesting period will last around 6-8 weeks.
Acorn Squash are ready to pick when the fruit is firm, glossy, and the bottom is cream to orange in color. The rinds should be difficult to penetrate with a fingernail; you may also wait until the plants start to die back. Make sure to harvest the squash with a sharp knife before the first hard frost with at leat 1″ of stem attached.
Blueberries will turn dark blue a couple days before they are actually ready. When it’s time to pick them, the berries will be firm, dark blue, and have a white powdery coating. Another way to tell if they are ready is that they should fall right off when you pick them.
Broccoli heads are ready to harvest when the buds are dark bluish-green and the stalks are firm. The buds are too ripe when the buds begin to open into flowers and should be cut immediately. Harvest broccoli by cutting it off 4″-6″ below the head. After the head is harvested, you will likely see smaller side shoots or miniature heads start to grow; harvest these in the same manner as the larger head.
Cabbage are ready to harvest when the heads feel firm; you should not be able to press in on the sides or top. In addition to trying to avoid heads with pale or wilted leaves, you will want to try to harvest your cabbage before the head splits. After the head has been removed – and you leave the plant in the ground – smaller heads may start to grow.
Muskmelons are similar to watermelons in that they should have a hollow sound when thumped. The color under the skin’s netting should be tan or yellowish instead of green, the melon should have a fragrant aroma, and the blossom end is a slightly soft.
You can quickly get an idea if corn is ripe or not just by looking. The husk should still be green and the silk at the top of the ear will be drying out. You can also check for the presence of a milky liquid when you pull back the husk at the top of an ear and puncture it with your fingernail. If you see water coming from the kernel, it is not quite ripe; if the kernel is empty, the corn is too ripe.
Grapes are ready to pick when they are plump, firm, and still tightly attached to the stem. Green grapes may have a little yellow coloring, red grapes should be dark red without any green remaining, and purple grapes should be almost black without any green remaining.
Lettuce – Head
Lettuce is ready to harvest when the head has a firm center with loose outer leaves. Using a sharp knife, cut the head 1″ above the soil.
Lettuce – Leaf
Use scissors to cut the lettuce leaves when they reach 4″-5″ long. Check the plants every few days to look for new leaves. Harvest all leaves before the plant “bolts,” or begins growing a flower stalk, and before a hard frost.
Okra pods are ready to pick when they are 2″-3″ long, or about 4-5 days old.
The easiest way to tell if a pumpkin is ready to harvest is by looking at its stem; it should be completely dried out. Their skin will also be firm, non-glossy, and be difficult to pierce with a fingernail. You should leave at least 1″ of stem attached to help prevent rotting in that area – and it’s harder to carve a pumpkin without a stem to hold on to the top with!
Ripe berries will be fragrant, plump, and have a uniform color. Raspberries should come off the vine easily.
Tomatoes are ready to pick when they are firm, smooth, and glossy. Although the actual skin color will vary slightly by type, the color should be uniform. Tomatoes will still ripen if you pick them before they are fully ready, but get their best flavor when they are able to ripen on the vine. Just before the first frost, be sure to pick all green tomatoes and let them ripen inside – or make fried green tomatoes.
Many people use the traditional “thumping” method in order to test the ripeness of a melon. Using this method, you can knock on the top of the watermelon; the watermelon is ripe if you hear a dull, hollow sound. There are also some other things you should check when trying to figure out if your watermelon is ripe or not: the stem will curl and turn brown, the melon’s skin will become dull, the skin will be hard to penetrate with your fingernail, and the spot on the bottom of the melon where it lays on the ground should turn from a white to yellowish color. When harvesting melons, cut the stem with a sharp knife leaving about 2 inches of the stem attached.
Those such as Acorn Squash, Butternut Squash, and Spaghetti Squash
The easiest way to tell if winter squash is ready to harvest is by looking at its stem; it should be completely dried out. Their skin will also be firm, non-glossy, and be difficult to pierce with a fingernail. You should leave at least 1″ of stem attached to help prevent rotting in that area.
Bigger isn’t always necessarily bigger, especially with zucchini. Although zucchini will easily get over 20″ long, its flavor and usefulness decline; the bigger the zucchini, the tougher it gets, and the more seeds you will have. Like some other vegetables, the more often you harvest, the more this summer squash produces. You should harvest zucchini when they are 6-8″ long. Store in refrigerator until used.