She did know the basics in picking a good watermelon: sounds hollow when knocked on, smells fresh on one end, and looks dark green with white stripes. When she bought fruits or vegetables, they would be either too green or too ripe.
What I would like to do is give you the basics on buying the best fruits and vegetables.
Potatoes
Whether they are red, brown, or yellow, potatoes should be hard when you squeeze them. Check for slices or soft marks. The soft marks mean that the potatoes are rotten. Also, if the potatoes look green, they are green. A good ripe potato will have color: brown, red, or yellow.
Summer Squash and Zucchini
Summer squash and zucchini should be firm when you squeeze them. The summer squash should be a good yellow color. The zucchini should be a dark green. If these squashes are soft, then they are either ripe or rotten.
Both squashes are great summer fare and if prepared properly, they taste light and summery.
Green Beans
Green Beans can be either dark green or light yellow. They should be firm and when you snap them you should hear a clear pop. If they don't pop, then they are probably over-ripe. Yellow beans cannot be white or light. If they are too light, then they are not ripe.
Peas do not pop, but should be firm when peeled from the casing. Peas taste better ripe. Sugar peas are peas that are eaten in the case. Most sugar peas that you find in the store are usually too old and hard, which make them hard to eat. The best sugar peas are the young ones in tender casings.
Tomatoes
The best tomatoes are the ones with a rich color, usually red. Tomatoes have more acid when they are green. I know that in the south you can get green-fried tomatoes. But, if you have stomach problems such as GERD, this is not a good dish for your stomach.
Tomatoes come in all sizes from round to grape. Also they come in orange and red.
Avocado
Avocados are actually fruit and grow in the tops of the avocado tree. The avocados that we get in the U.S. are under-ripe so that they do not spoil. Unfortunately to a connoisseur's taste bud, avocadoes do not taste good when bought in an under-ripened state and then prepared after allowing them to ripen.
The best avocados are tree-ripened. When you pick up this fruit, the outside peel is black green and textured. When you squeeze it, it is soft. Inside the avocado is two colors of green (medium and light).
Since I have had the opportunity to eat fresh avocados in South Africa and Panama, I sometimes have to pretend that the avocados sold in the states are an entirely different fruit.
Pineapples
I learned in South Africa how to pick the perfect pineapple. You smell the bottom of the pineapple. If it smells sweet and is sticky, then it is a great pineapple. Like the avocado, the pineapples that you find in the grocery stores are usually under-ripe.
Here are a few of the tricks that I have learned by being a farm girl and by travelling on how to pick the best fruits and vegetables to put on my table. If you grew up in the northwestern part of the country, I am sure that you already know how to pick the best red delicious apples. Or if you eat melons in the summer, I am sure you have your own way of picking them. But, for me I like having the freshest on my table. I am sure that you do too.
And the best produce? Go to your local farmer's market.