Generally, for freezing anything, the faster you can freeze it, the better. Ice crystals grow as things freeze, and if they grow slow, they grow big, and they disrupt the structure of the food, and make the texture mushy.
Something I frequently freeze is greens like kale. I’ll harvest more than I can eat from my garden, so I freeze it. I basically wash it, then lay it out on cookie sheets in a single layer, and put those in a chest freezer. After I’ve had enough time to wash the next batch, I’ll go down and peel the frozen kale off the cookie sheet and put it into a container of some kind.