Plums are a beautiful addition to any orchard and even dwarf varieties can be heavy producers. There are two different types of plums you can choose from. European plums have dark skins and yellow flesh. They are not as cold tolerant as Japanese plums. Japanese plums are red or golden skinned and have a firmed texture to the meat. They can tolerate the cold better and in fact require more chill hours in winter to be able to produce the next spring.
All plums require cross pollination. Japanese plums are very dependent on cross pollination from other trees that have beneficial traits. This can make it quite an issue when you first start your orchard, as some types of trees are in such high demand that they can sell out early. So if you plan on planting a stand of plums in your orchard this year, it is best to find a reputable dealer and pre-order while there is still plenty of snow on the ground. I didn’t take advantage of this when planting a stand of plums and as a result, my mature plums flower each spring then do poorly because their preferred partner is two years less mature and not able to flower yet.
European plums are far more forgiving. While they do need to cross pollinate with another plum that has beneficial traits, there is a wider range of European plums to choose from, so you aren’t as likely to be forced to pre-order.
Growing zone: Zone 5 to 8 for European plums. Zone 4 to 7 for Japanese plums.
Time to maturity: 3 to 5 years. Japanese plums are more likely to be closer to 3 years, European are more likely to take 5 years to produce.
Pollination needs: All plums require cross-pollination by companion trees with beneficial traits.
Pruning/Thinning: European plums need to be trained to a central leader, just like apples. Japanese plums because they sprawl out need to be trained to an open center. Japanese plums also have a penchant for crowding their branches with young new shoots. Once they are established, they will need yearly pruning in order to maintain proper ventilation.
Harvest time: Both types of plums ripen between early August and early September.
One of the biggest differences between the two plums, aside from the fruit, is their soil preference. European plum will actually tolerate moderate clay soils. This is related to the higher water and sugar content of their fruit. This makes European plums very attractive to people whose clay soil has limited their options.
Japanese plums are much more like apples in that they do not like having wet roots. This is probably a product of their crisper fruit. At the same time they still do require adequate moisture. So if you have overly sandy soil and struggle with the soil drying out, it is a good idea to apply a heavy amount of mulch around the tree, all the way out to the drip edge. Just be mindful to plant the tree a little higher so that the thick mulch layer doesn’t end up burying the crown or grafting swell of the tree. This could lead to the tree developing suckers from the crown and ultimately reducing the energy it puts into developing the main trunk.
Long term storage options: Japanese plums can be picked slightly under ripe and they will continue to ripen for up to one week at room temperature. European plums will not continue to ripen after picking.
Plums do not keep well in the long term as whole fruit. Instead it is better to either dry them into plums, can them as jam or process into wine. You can cut them in half, remove the pit and freeze them in quart sized zip top bags. They will keep in the freezer for 6 to 8 months. You can then thaw them, chop them and cook into a fruit chutney, sauce or fruit salad.
Plum wine is a real treat. Since the price of plums at the grocery store is so high, it isn’t very cost effective to make wine with store bought fruit. However the large volume you can get from your home orchard allows you to chop, press and juice the fruit in significant volume. While you can blend it with other fruit juices, plum wine is the sort of desert wine that can stand alone.