Plum Pollination 


Generally, Japanese plums need to be pollinated by Japanese plums and European plums need European pollinating partners. This is because the Japanese plums bloom very early and are almost always finished well before the European plums start to bloom. So the pollen from one type is simply not available at the right time to pollinate the other type. 

The Crosses are best pollinated by any Japanese plum. 

About Plums 


Among a number of fruit trees, plums figured prominently in the Hanging Gardens of Babylon in the 6th century BC. King Nebuchadnezzar built the gardens to assuage the loneliness of his Persian bride, indicating that plums were popular in the culture as well. 


As far back as Roman times, there were already over 300 varieties of European plums. As with many other fruits, the colonists brought them to America. Japanese plums were originally found in China, but their cultivation prospered in Japan. They came to the US in the late 1800’s.


The most popular plum in America today is the Santa Rosa plum. It accounts for nearly 1/3 of the total plum crop. It was developed by Luther Burbank, in his Santa Rosa, California research garden. Luther Burbank has been called the “Thomas Edison of Fruit.”  In a career lasting over 50 years, Burbank developed more than 800 varieties of fruits and plants. Among his diverse group of friends were John Muir, Thomas Edison, Freda Kahlo, Henry Ford, Helen Keller and Jack London. 


Plums fall into two basic types: European and Japanese. There are also some interesting cross bred varieties. Plus, there is the beautiful native beach plum which grows wild in many places and produces a delicious little plum that makes excellent jam.
Japanese plums are a bit of a misnomer, as they originated in China, but were proliferated by the Japanese. Also a bit confusing, the names of many Japanese plum varieties don’t sound very oriental (like Elephant Heart). 

Plum Pruning


Plum trees offer a very nice show of white flowers in the early spring. The Japanese varieties are especially early. They are prolific growers, branching very heavily and growing rapidly.

First year pruning sets the eventual shape of the tree. If your tree is taller than 4-5' above ground, after its planted, trim it down to that height. Pick out the dominant branch that is the most vertical at the top of the tree. This will be your central leader. Thin out the inward growing branches and any branches which are crossing over each other. Trim off the tips of the larger branches to encourage growth. See the diagram for a look at the branches.

Any shoots or branches which come from BELOW the “bud union” should always be pruned – now and in the future. Brand new stems that grow out of the ground, from the root systems are called suckers. If you see them, cut them off at ground level. When the tree matures, suckering usually diminishes.

If your trees set fruit this first year, pick off some of the immature fruits, spacing them about 8" apart on the branches. This will encourage proper ripening, allow the spray to cover well, and improve vegetative vigor. Fruit thinning in the future is also important for the very same reasons. Less is more. If you don’t thin, you will get many more fruits than the tree can handle, resulting in broken branches and small fruits. Don’t be afraid to thin. The resulting fruits will be fuller and much nicer.

In later years, you should continue “shape” your tree. Plum trees are best trained to a modified central leader (uppermost upright limb) or to a vase shape like peaches and nectarines. It does not want to grow straight up like and apple or a pear, so the central leader will become much less dominant. It will want to spread and try to take over your orchard. This is the natural way your plum tree will want to grow. Pruning will keep your tree vigorous, encourage the establishment of fruit buds, and enable you to keep your tree down to a manageable size. 

As plums are vigorous growers, you need to prune aggressively. Summer pruning, when the trees are still growing, will help contain the spreading nature of your plum tree. You cannot over-prune a plum tree. So do clean up pruning in the winter, to get rid of broken and dead branches and shape up the tree. Then in July, prune again to maintain a manageable size.