Corn- Corn is best stored in a cool environment, so your local supermarket should be displaying corn in refrigerator bins. Great quality corn should have full, evenly formed ears, with straight rows of bright kernels. The husks should be bright green with the silk ends free from decay.
Summer Squash- should have a bright, smooth skin, (dull skin is a sign of old age,) with stem ends that are fresh and green. Squash should also be firm and plump without any soft spots or pitting, and fairly heavy for its size.
Beets- Beets should be a relatively smooth, round, firm, small to medium size with a deep red color and a tap root that is slender. To store, cut the leaves from the root, leaving an inch or two of the stems attached, place in a plastic bag, and keep in the refrigerator 1-3 weeks.
Cucumbers- Select cucumbers that are firm and display a good green color. They should be well shaped but not too large. I favor the smaller cucumbers because they tend to be less bitter.
Green Beans-Overall, it is best to purchase green beans from a supermarket that sells them loose so you can better select them for color, freshness, texture and size. Green beans should be fresh looking, with a bright light to dark green color. Make sure the beans are plump and firm, with a velvety feel, and free from any sign of decay.