Beans
If you plant in mid- to late spring, beans continue to set through most of the summer if you keep picking them. For best flavor, pick them when they are thinner than a pencil.
Test Garden Tip: For variety, harvest some immature, or baby, beans and add them to salads. They have a slightly different flavor when they're young.
Carrots
Carrots are fully ripe when their shoulders reach up out of the ground and the leaves turn a rich, darker green than they were during the growing season.
Test Garden Tip: If you get impatient, you can harvest carrots as soon as they're large enough to eat. Plant extra so you can harvest baby carrots during the growing season while you wait for them to fully mature.
Corn
If you grow newer corn hybrids, they'll hold their flavor for a week or maybe more. But regardless of the type, it's best to wait until the silks at the ear tips turn brown. Feel the ears and make sure they're full and solid.
Test Garden Tip: If you're not sure, peel back the shuck and pierce a kernel with your fingernail. If the juice looks milky, your corn is ready. If the juice is clear, give the corn a little more time.