In a good year, there doesn’t seem to be such a
thing as a small crop of zucchini.

If you find yourself blessed with too much zucchini to eat and share with friends, here are some ways to preserve some for later. Canning zucchini alone is not recommended. The zucchini is low in acid, so it must be processed in a pressure canner. The high water content makes the vegetable soft and it is hard to regulate how much is
placed in the jar, therefore it is difficult to recommend the proper processing
time. Zucchini may be combined with tomatoes and pressure canned if an approved recipe is followed, such as the one found at National Center for Home Food Preservation http://www.uga.edu/nchfp/how/can_03/tomato_okra_zucchini. html

Canning. Zucchini can be preserved in a water bath canner as a pickled product, or with pineapple juice. The vinegar or pineapple juice will add enough acid to prevent botulism. With less cooking, the zucchini will not get so soft and mushy. Pickled bread and butter zucchini, vegetable relish, or zucchini relish can be processed in a water bath canner, since the vinegar makes it safe to use less heat.

Drying. Zucchini can also be preserved by drying, but it does not provide a high quality product. To dry the zucchini, it should be washed, trimmed, and cut into ¼ inch slices. The zucchini slices should be water blanched for ½ minute or steam blanched for 3 minutes. It will take 10 to 12 hours to dry in a dehydrator.

Freezing. Freezing will provide the best quality product, if plain zucchini is what you want to preserve. As with all foods, it is best to start with high quality produce. Choose young squash with tender skin, wash the squash, cut it in1/2-inch slices, and blanch it in boiling water for 3 minutes. Cool promptly, drain and package, leaving 1/2-inch headspace. Seal the container and freeze. If the zucchini is to be used for baking, grate the zucchini before freezing. Steam blanch a small quantity at a time for 1 to 2 minutes until translucent. Measure the amount used in a favorite recipe or measure a set amount and pack in containers, leaving 1/2-inch headspace. Cool by placing the containers in cold water. Seal the container and freeze. If the zucchini is watery when thawed, discard the liquid before using the zucchini. Another way to use and freeze zucchini is to make freezer jam.  Keep in mind, this is not safe to can or keep at room temperature.