Covering vegetables with plastic shelters during the cool or cold time of the year often improves results in other ways, so you might want to start doing that anyway.

thanks BBoy: what would you use as a cover? Would it make it stay too wet? I was going to use leaves, but was not sure if it would keep it wet? Thanks

Have a look at this.

Here is a link that might be useful: Row cover - Wikipedia, the free encyclopedia