Growing fruit trees in Montana is challenging. The short growing season will severely limit your choice of varieties if you goal is to actually harvest a crop. Even those hardy varieties that can survive the Montana winter and produce fruit quickly will need extra care if you want your fruit trees to thrive. Dry conditions, high pH soil, and hungry wildlife are other hurdles you must overcome if you want to grow fruit trees in Montana. Many will find the extra effort is worth it.
Looking at a high level growing zone map, it will roughly look like the northern half of the state is in growing Zone 3, and the southern half is in Zone 4. There is also a relatively small part of the state tucked away on the western side that falls into Zone 5. Don't depend on this high level view, though. All across Montana, there are micro climates. Within just a few miles, the growing season can range anywhere from 30 days up to 130 days. Temperatures can vary up to 20 degrees in areas very close together. If you are going to take the time (years) and dedication to grow fruit trees, invest some time up front to understand what climate you will be growing in. If the high level maps show you are in Zone 3, but your area is really more like zone 4, you may be limiting your options needlessly. If the big maps show Zone 4, but you are really in a Zone 3, you could end up with unhealthy, non-producing trees. Check with the Montana State University Extension program for their publication on “The Climate Atlas of Montana.”
Zone 3 options for fruit trees are limited to a few varieties or apples, and one variety of crab-apple. McIntosh Apples have a long and storied history in Montana, though some other varieties are better adapted to the colder parts of the state. Gravenstein, Haralson and Yellow Transparent are the hardiest options, but you should also be able grow Honeycrisps, Snow Fameuse and Wolf River varieties.
If you don't mind the tartness, you might want to also consider the hardy Dolgo crab-apple tree. In addition the the fruit, this tree serves as a pollinator for other apple trees.
Your options in Zone 4 are much wider. You have all of the options available to Zone 3, but there are another dozen or so apple varieties that you can choose from including Breaburn, Cortland, Orange Pippin, Gala, Liberty, McIntosh, Mutsu, Northern Spy, Red Delicious, Red Johnathan and others. You can also add Snowdrift and Prairiefire crab-apples to you list. Check with a local nursery to get recommendations and options.
In Zone 4, you can also grow a number of Apricot, Pear and Plumb varieties. For Apricots, you can grow Chinese, Gold Cot, Goldbar, Goldstrike, Moorpark and Tomcots. Pear varieties include Bartlett, Bosc, Comice, D'Anjou, Kieffer and Shinko. Your plumb options are Green Gage-Bavays, Methley and Superior.
For cherry trees, the sour Montmorency is your best bet, but you should also be able to grow the sweet Rainier and Van varieties. Reliance Peach trees may also produce for you, but be sure your soil has a pH under 7.
If you are willing to consider options other than fruit trees, your choices will widen dramatically. Non-tree fruit plants that you can grow in Montana include blueberries (sometimes called huckleberries), currants, gooseberries, grapes, raspberries and strawberries. Some varieties of these fruits will produce abundantly in either Zone 3 or Zone 4. The Low Bush Blueberry is native to Montana, and it has a high tolerance for cold weather. The Brandywine Raspberry is another cold hardy plant you may wish to consider. Check with your local plant nursery, or do some research in gardening catalogs or on the Internet to make sure you pick a berry variety that will produce and survive in your zone.
If your heart is set on trees, you may wish to consider a few nut trees. The Filbert tree is native to Montana and will produce sweet nuts with a thin shell. Black Walnut trees and Chinese Chestnut trees are cold hardy and produce well in Montana.
The soil in many parts of Montana has an elevated pH level. This will stunt the growth of your fruit trees. Have your soil pH level tested, and amend as needed. Sulfur amendments will bring down the pH level and help your trees to grow and produce better.
Wrapping your trees will help them to survive the cold Montana winters. The large temperature changes can cause the trunk to crack. This weakens the tree and makes it easier for rodents and other creature to feed on the living part of the tree. To help with this issue, simply use a tree wrap from late fall to early spring.
Understand your trees pollination requirements. Many fruit trees cannot self pollinate, and they need other varieties to be growing nearby. Even trees that can self pollinate often produce better when near other varieties.
There is nothing like growing your own fruit. While the climate in Montana may limit your options, and require a little more work, there is no reason why you cannot enjoy fresh fruit from your own trees. As it takes years to grow producing fruit trees, take the time up front to make sure you choose varieties that will produce in your climate. Also take the time to understand what other steps you will need to do in order to enjoy those delicious fruits of your labor.