If you have a small space for a tree, purchase a tree on dwarf rootstock, which takes up less space and stays short enough to make picking fruit easier. Give dwarf trees at least 5 feet of space between other trees to maintain some vigor and health. Fruit trees can grow well in a variety of soil types as long as the soil is well-drained. If you are growing standard-size fruit trees, you should have soil that is 4 to 9 feet deep. Soil that is 3 to 5 feet deep is sufficient for growing fruit trees on dwarf rootstocks.
If your soil is compacted and shallow, you may decide to make raised beds. For dwarf fruit trees you will need at least 2 feet of raised bed on top of a foot or two of soil.
When planting a tree in the ground, do not add a large amount of purchased topsoil or compost to the hole to improve the soil. A little compost mixed with the native soil will be sufficient. The tree's roots will not leave the planting hole if the modified soil is much lighter than the native soil.
Don’t put any nitrogen fertilizer in the planting hole. During the first year, allow the tree to grow for several months before applying nitrogen to the surface of the soil. This will keep you from burning the young tender roots.
Here are some suggestions for your area:
Thank you for using Ask an Expert--and congratulations for asking about varieties of several fruits BEFORE you purchase whatever is in the store, because many times retailers stock the most well-known varieties without careful consideration of what really does grow well.
Apples
Semi dwarf and dwarf apple tree varieties produce fruit in 2 to 3 years. Semi dwarf varieties usually are 12 to 15 feet tall. Cross-pollinations recommended for all apple varieties to produce fruit. Crabapples planted within a quarter mile of your apple tree may serve as a pollinizer if bloom times align.
Gala, Honeycrisp, Liberty, Golden delicious, Lodi, Yellow transparent, Jonathan, Red Baron, are all popular varieties.
Asian pear
Asian pears often are referred to as “apple pears” because of their crisp, juicy texture. Asian pear trees are considered partially self-fruitful. However, cross-pollination with another Asian or European pear variety is recommended for improved fruit set. Atago, Kosui and Seuri are popular.
Pears
For Pears, cross-pollination is necessary! Plant at least two varieties that are compatible for pollination and that bloom at the same time. Almost any pear will work as a pollinizer of any other pear; however, Bartlett is a poor pollinizer of Seckel. Pear trees grow best in deep, finely textured soil with good drainage, such as silt loams or clay loams. Pears do not thrive in gravelly soil. Bartlett trees can be planted as close together as 15 feet. Most other standard pears will need 20- to 25-foot spacing and will grow as tall. A pear on a dwarfing rootstock will require about 15 square feet if allowed to keep its natural shape, but with proper training methods it will grow flat against a fence or wall in very little space.
Here are some favorite varieties for Oregon gardens and good pollinizers for Bartlett:
D'Anjou, also called Beurre D'Anjou, was introduced to the United States from France in 1844. It is a high-quality winter dessert pear.
Bosc, also called Beurre Bosc, comes from a chance seedling found in Belgium in 1807. A fine-flavored dessert variety, it has russetted skin.
Comice originated near Angiers, France, around 1840. This variety is grown in the Medford, Oregon, area as a specialty gift-box pear. It is one of the finest for eating and drying but is not recommended for canning.
Cherries
Most sweet cherry varieties are self-unfruitful and require cross pollination with another variety as the pollen source.
Bing does well with Sam, Van, Rainier, Stella, Compact Stella, and Garden Bing.
Lambert does well with Sam, Van, Rainier, Stella, Compact Stella, and Garden Bing.
These are all great sweet cherries for our area.

Popular nuts include hazelnuts, chestnuts and walnuts.

I have attached a couple of publications you may find useful.

https://extension.oregonstate.edu/gardening/berries-fruit/planting-caring-fruit-tree

https://extension.oregonstate.edu/news/growing-nut-trees-your-back-yard-or-orchard