You can get the most delicious vegetables from your home garden, you need to harvest them when they are at their peak of flavor. There are no hard and fast rules for the perfect time to pick. Great flavor isn't a simple matter of size or color. Without the right combination of soil, sun and water many vegetables can vary greatly in taste and performance. However, there are some rules of thumb that let you know it's time to start taste testing your vegetables, because tasting is really the only certain way of knowing it's time to pick.
For maximum flavor and the most pleasant texture, most vegetables are harvested just before full maturity. The following are vegetable harvesting criteria for judging whether your vegetables are ready for picking.
When to Harvest Your Vegetables
■ Asparagus: Begin harvesting when spears are 6-8 inches tall and about as thick as your small finger. Snap them off at ground level and new spears will continue to grow. Stop harvesting about 4-6 weeks after the initial harvest, to allow the plants to produce foliage and food for themselves.
■ Beans (Snap): Pick before the you can see the seeds bulging. They should snap easily into two. Check daily. It doesn't take long for beans to go from tender to tough.
■ Beets: You can harvest and eat the green tops when you thin out of the rows. Beets are really a matter of personal preference when it comes to the right size for harvesting. They are ready any time after you see the beets shoulders protruding at the soil line.
■ Broccoli: We eat the unopened flower buds of broccoli, so check frequently, especially as the weather warms up, to ensure you don't let the flower heads bloom. Don't expect your home grown broccoli to get to the size of supermarket heads. Harvest when the individuals buds are about the size of a match head. After the first harvest, smaller side shoots should continue to form. Here's some help, if your broccoli doesn't from heads.
■ Brussels Sprouts: The sprouts will mature from the bottom of the plant up. You can begin harvesting once the sprouts are at least an inch in diameter. Harvest by twisting off or cutting the sprout from the stem.
■ Cabbage: The cabbage head will feel solid when gently squeezed. Cabbage needs to be harvested when it reaches maturity or it will continue to grow and split open.
■ Carrots: Carrots can be hard to judge. The tops of the carrot will show at the soil line and you can gauge when the diameter looks right for your variety. If the diameter looks good, chances are the length is fine too. But you will need to pull one to be certain. Carrots can be left in the ground once mature. A light frost can improve and sweeten the carrot's flavor.
■ Cauliflower: As with broccoli, your home grown cauliflower heads will probably never match supermarket size. Harvest when the head looks full and while the curds of the head are still smooth. Leaving them for too long will result in brown spots and a mealy texture.
■ Corn: About 3 weeks after the silks form, they will turn dry and brown. That's when you should start testing the ears by nicking a kernel with your fingernail. The kernel will exude a milky substance, when it's ready to harvest..
■ Cucumber: Cucumbers race to the harvest like zucchini. Check daily and harvest young. Timing and length will vary with variety. The fruits should be firm and smooth. Over ripe cucumbers can be very bitter or pithy, even before they start to turn yellow.
■ Eggplant: Eggplant has the best flavor when it is still slightly immature.. The fruits should be firm and shiny. Cut rather than pulling from the plant.
■ Garlic: The garlic tops will fall over and begin to brown when the bulbs are ready. Dig, don't pull, and allow the bulbs to dry before storing. It's best to simply brush off the dirt, rather than washing.
■ Kale: Kale leaves can be picked throughout the season. You can cut an entire plant, but you will get a longer harvest if you harvest in the cut-and-come-again method. The leaves should be a deep green with a firm, sturdy texture. Kale flavor is best in cooler weather.
■ Kohlrabi: For the best texture, harvest once the kohlrabi bulb has reached about 2-3 inches in diameter. The bulbs become tougher as they grow and age. Pull or slice at the base.
■ Leeks: You can start harvesting leeks when they are about 1 inch in diameter. Leeks can be left in the ground over winter, in most areas, and harvested as needed.
■ Lettuce (Head): Harvest once the head feels full and firm with a gentle squeeze. Hot weather will cause it to bolt,or go to seed, rather than filling out.
■ Lettuce (Leaf): Harvest the outer leaves one the plant has reached about 4 inches in height. Allow the younger, inner leaves to grow. Leaf lettuce can be harvested in this fashion for most of the summer.
■ Muskmelon: There are many varieties of muskmelon, but a general rule of thumb is that the color should change to beige and the fruit will ‘slip’ from the vine when lifted. You should also be able to notice a sweet smell when ripe.
■ Onions: Onions can be dug once the tops have fallen over. Allow the onions to dry in the sun, before storing.
■ Parsnips: Parsnips taste best if they are left in the ground until after a frost or two. They can even be left in the ground over the winter and harvested in the spring. In cold areas, they should be mulched for the winter.
■ Peas: The pea pods should look and feel full. Peas are sweeter if harvested before fully plumped. Peas really need to be tasted to determine if they are sweet enough.
■ Potatoes: ‘New’ potatoes can be harvested when the tops of the plants start to flower. Carefully dig at the outer edges of the row. For full size potatoes, wait until the tops of the potato plants dry and turn brown. Start digging from the outside perimeter and move in cautiously to avoid slicing into potatoes.
■ Pumpkins: Once the pumpkins have turned the expected color and the vines are starting to decline, check to make sure the skin has hardened enough by poking it with your fingernail. You should not be able to poke through the skin. You don’t want to pick your pumpkin too soon, because it will stop turning orange once it’s cut, but don't leave them out if a hard frost is expected.
■ Radishes: Radishes mature quickly. You will see the shoulders of the bulbs popping out of the soil line. Harvest regularly. If left too long, they will become tough and eventually go to seed. Rather than planting a large crop all at once, plant your radishes in succession.
■ Rutabaga: The bulbs should be about 3 inches in diameter, generally about 3 months after setting out. Rutabagas can be mulched in the fall, left in the ground throughout winter, and dug up as needed. Cold weather improves their flavor.
■ Swiss Chard: As with leaf lettuce and kale, cut the outer leaves and allow the center to continue growing, in the cut-and-come-again fashion.
■ Spinach: You can harvest individual young leaves once the plant is about 6 inches tall. Spinach goes to seed quickly. As the plants mature, harvest by cutting stems at the soil line before you see a flower stalk beginning to shoot up.
■ Squash (Summer): Whether it is zucchini, yellow squash, or patty pan, pick young and check often; they grow extremely fast. The skins should be tender enough to poke your fingernail through.
■ Squash (Winter): Color is a good indicator of winter squash maturity. When the squash turns the color it is supposed to be, cut from the vine. Do not let winter squash be exposed to frost.
■ Tomatoes: Harvest tomatoes when they are fully colored and slightly soft to the touch. They should also give off that distinctive tomato scent and pull easily from the vine, when given a gentle twist.
■ Turnips: The turnip shoulders should be about 2 to 2 ½ inches in diameter at the soil line, when ready. Harvest once they reach maturity. Overripe turnips become woody.
■ Watermelon: The white spot on the bottom of the melon should change to a deep yellow when ripe. Some people can hear a change in the sound made when the melon is thumped with a finger. It should make a hollow sound when ripe, but this is a skill that must be developed.
taken from https://www.thespruce.com/when-to-harvest-vegetables
till next time this is Becky Litterer, Becky's Greenhouse, Dougherty Iowa