I had a conversation with a new gardener yesterday, who was a bit confused about when her veggies were ready for harvest. Tomatoes were easy, but what about carrots and onions? And with crops that you can obviously harvest at various sizes -- squash, cukes, lettuce -- does it matter when you pick?
Actually, harvesting at a particular time can make a difference -- in flavor and in plant production. A squash that's five inches long will taste better than one that's allowed to become a baseball bat. And veggies that are allowed to grow too big cause the plant to slow (or even stop) producing new veggies.
Since those zucchini logs are usually the result of one veggie being overlooked beneath a sea of foliage, rule No. 1 of vegetable harvesting is go through the garden daily to see what's ripe.
Maybe you figure it doesn't matter much if a zucchini plant slows down a little -- but it will if squash borers arrive and that's the end of your harvest for the summer.
If you're a relatively new gardener, it helps to know the number of days it typically takes for the vegetables you planted to reach maturity and the size they're supposed to be then.
Sweet Dumpling squash, for instance, will be a different size than Yellow Crookneck and take longer to reach its harvestable size. This information is on the plastic label that was in the pot when you bought the plants or in the catalog description.
I always recommend saving labels. Keep them together in a garden notebook. But if you didn't do that and you remember the name of the variety (Sugar Dumpling squash), you can look it up on the Web. If you do, write it down in your notebook. I find that it often comes in handy later.
You should also know that it isn't necessary to cut an entire plant of leaf lettuce at once -- just pick off the outer leaves as you need them. Then the plant continues to grow and produce more leaves for your salads.
Here are some charts you can print out that give you clues to the optimum harvest size for all that you grow: