Richard R. MacMahon, Ph.D.
Just as plants need to be planted in a time sequence, so they are ready to harvest at different times. The first plants normally ready are the radishes (for which I usually give a prize for the largest). These are followed sometime later by the peas, then beans and lettuce and parsley. Later still, during the summer, cucumbers, tomatoes, peppers, corn, etc. are ripe. There are also plants that ripen in the fall, such as winter squash and pumpkins. Some plants, such as kale, may be harvested up until frost.
The problem is, that no one ever seems to say much about how you harvest the produce. There are some suggestions in the organic gardening books (see Appendix 3) but no really good and complete instructions. This leaves the students on their own. They must use their own judgment. In addition, most things will ripen after school is let out for the summer.
The best solution is to have some kind of organized summer activity that will help the students to tend and harvest their own gardens. If this is not possible, students may still work on their gardens on a volunteer basis and on their own. But there must be some thought given to security. Is the garden site a place where students may safely go alone? If it is not, then a group activity is needed.
Fall plants may be harvested either by the original students or by a subsequent class given in the fall. Classes that are working in the fall can prepare the site for winter and harvest the fall produce. We are trying a program this fall where all of the produce harvested will be weighed and measured. The class will then calculate yields of various plants.