Store freshly picked, unwashed zucchini in a plastic bag in the refrigerator for up to one week. The bag should be perforated or loosely tied, not sealed tightly. Do not cut the zucchini until you are ready to use it or freeze it.
Prepare for Freezing
Wash the zucchini, and pat it dry. Trim off the ends, then slice it crosswise -- peel and all -- into 1/4-inch thick sections.
Choose Quality Containers
Package the zucchini slices in containers designed for freezer storage. Use plastic bags or boxes that will not crack easily, will keep out moisture and will seal completely. Using containers that are not sturdy enough, such as sandwich or storage bags, will not prevent freezer burn and the absorption of odors from the freezer. Look for the word "freezer" on the packaging of the bags you buy.
Blanch for Longer Storage
Blanch zucchini slices to keep them longer. Blanching preserves the nutrients and flavor well, so blanched zucchini can be frozen for up to one year. To blanch, boil a large pot of water, then boil the zucchini slices in the water for three minutes. Remove the zucchini slices from the water and place them immediately in ice cold water to cool quickly. Put the cooled slices onto clean towels to drain them, and then place them in freezer containers.
Use a permanent marker to label and date each bag. Dating is important so that you can use the zucchini in the order in which it was stored. If you freeze some in early July and more in late August, cook the older packages from July first.