I want to buy several dwarf fruit trees to grow in containers (apples, cherries, peaches, nectarines, pears, grapes and bramble berries and strawberries). What size containers do I need for them and what do I have to do for them regularly to keep them healthy? I live in eastern Tennessee, Zone 7, and will not be able to bring them in for the winter, but I can put many bales of hay around the containers for insulation. I don't want to plant them in the ground until I can get a place where I know I won't move from.
This article should help you with that: https://www.gardeningknowhow.com/edible/fruits/fegen/dwarf-fruit-trees-a-planting-guide-for-fruit-trees-in-containers.htm
When should I plant these trees? I was told in the spring or late Feb. or March. I live in southern California.
Yes, spring would be the best time. There is normally more rainfall and lower consistent temps at that time and so the trees have a better chance of establishing.
I would like to know if a dwarf fruit tree planted in a container should be covered when temperatures drop to below 50 degrees and conditions become windy?
The following article should be of some help to you:
Typically, container plants, such as these, are brought indoors rather than being covered.
What type of fertilizer do I need to feed my trees?
I would go with a phosphorus rich fertilizer. This will help with fruit production.
Is it ok to plant into a container now, then later transplant into the garden, say later this spring, fall, or next year? I have just received some dwarf cherry and peach fruit trees and the ground has been and still is too wet to work up at this time.
Yes, this is fine. The following article should be of some help to you as well:
Why does the newly formed fruit drop from my trees? I have a Meyer lemon and an orange tree both full of blossoms and I am anxious not to lose the fruit this year.
Most citrus fruit share many of the same issues, especially lemons and limes. Therefore, this article should help: https://www.gardeningknowhow.com/edible/fruits/lime/is-lime-fruit-and-lime-blossoms-falling-off-tree-normal.htm
I want to plant these in my yard in Cincinnati, Ohio.
Apple, pear, peach and nectarine would all grow where you are. Be sure to choose varieties that are cold hardy for your area. Apple and pear will mostly be good for your area, but peach and nectarine, you will need to double check their hardiness as there are some that are cold hardier than others.