Cucumbers can be frozen if they are prepared in brine prior to freezing. Cucumbers can also be frozen if they are juiced or pureed and ladled into an ice cube tray, according to HGTV Gardens.
To create a brine, layer sliced cucumbers and onions together in a large bowl. Sprinkle salt evenly over the cucumbers and onions. Allow the mixture to sit covered for two hours. Rinse the mixture until it is free of salt. Combine 1/2 cup of vinegar with 1 1/2 cups of sugar, and pour the mixture over the cucumbers. Ladle the cucumbers into freezer bags or freezer-safe Mason jars, and freeze for one week.
When prepared correctly, frozen cucumbers stay fresh for 12 months. Brine allows cucumbers to keep a crisp consistency, similar to pickles. Frozen cucumbers are often referred to as "freezer pickles."