Most plants do better when planted in the spring. You can plant an apple tree now, but it is getting late to do this and the tree will not be in as good a shape to withstand the winter as a tree planted in the spring would. If you can wait, I would recommend it.

You almost always want to plant strawberries in the spring. Strawberry plants are only productive for a few years, so you really want to get the most out of each one. A plant that is for sale right now will have lost one whole year of that potential growing period. I would make an exception if you have recently rooted runners - plant them now.

BP

Fall can be a great time to plant trees, if we are talking about potted nursery trees as opposed to bare root stock. If the trees are hardy for your zone, they likely will do alright. They won't put on any top growth, but if you keep watering them into fall freezeup they will develop roots. One thing, however, if the trees you are buying aren't on sale or not the variety you want (most nurseries have limited stock this time of year), perhaps you are best to wait until spring. If you get a great price, however, I'd be willing to take the chance.

Glen

I usually plant my strawberries in Fall so I don't waste an entire season waiting for roots to develop.
I find by planting them in the fall, you get just enough roots development so that when spring comes around the plant just explodes with strawberries and they're good for another 2 years. And by the time the 2 years go by, i take some clippings and re-plant them for best results. Beats going to HD and paying $10 for a plant.

Speaking of which, I have lots of strawberries ready to be picked right now, not to mention A MILLION TOMATOES!