Santa Rosa Plum Stops Bearing

Question from Debbie:
8 years ago we planted a Santa Rosa plum (Sunset 23, Pacific Palisades). for the first few years it had 3 or 4 plums – delicious! The tree kept growing(like crazy), but my gardener has pruned it hard in Dec or Jan for the past 3 years, and now we have plenty of flowers in Feb/March, but no fruit. Should I tell him to stop? The new small Santa Rosa next to it set fruit. Used fertilizer spikes. 2nd year for apricot tree, 150 fruits!

Answer from Pat:
I am very sorry to hear about what happened to your plum tree. Plum trees come in two types, Japanese and European. The European plums need very little pruning. The Japanese types take heavy pruning. Santa Rosa is a Japanese type of plum. The fact you got plenty of flowers though no fruit shows your gardener did not over-prune the tree, but the lack of fruit probably came from lack of a pollinator.

Santa Rosa plums are self-fruitful, but they still need to have the pollen transferred from the male part of the flower to the female part in order to bear fruit. Your problem most likely resulted from lack of bees to do this pollination. Rain and cold temperatures sometimes keep bees in their hives. Spraying with chemicals when there are flowers open can kill bees. Bees pollinate the flowers on a self-fruitful tree by going from flower to flower all over the tree. Cross pollination occurs when the bees visit various trees and mix the pollen from tree to tree. Some plum varieties need cross pollination but Santa Rosa does not. Next year if you see no bees, get a sable brush and go from flower to flower swirling the brush inside individual flowers here and there all over the tree. You should then get fruit! Do the job in the morning after the dew has dried but while the pollen is still fresh and keep it up for several days doing some flowers every day. The more flowers you pollinate the more fruit you will get.

Fertilizer spikes are not the best fertilizer for fruit trees. A better choice is to fertilize all over the ground under the tree when flower buds swell with a balanced organic fertilizer recommended for deciduous fruit trees or follow the suggestions in my organic book.

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Comments

  1. You are welcome. In the top paragraph, last sentence, I see I made an error in terminology. I was thinking of a bee as a pollinator, but that was the wrong word to use. Actually a pollinator is another tree providing cross pollination, which your tree does not need. Another point: Even self-fertile trees like yours will benefit from cross-pollination even though they don’t absolutely need it in order to bear fruit.

  2. Unfortunately plum trees are not as prolific as some other fruit trees. Also when there are few blossoms this often is the result of sharp temperature swings killing the flower buds or, sadly, it often can be the result of incorrect pruning. Never over-prune a plum tree, but always follow up with dormant spray. When pruning just cut off the dead and dying wood. Usually that’s all that’s needed. Frequently people accidentally cut off the blooming wood. Plums can bloom on the same branches for many years. If you cut off the flowering branches it’s going to take the tree a few years to develop new ones. In August be sure to remove the watersprouts (unwanted shoots, shaped like buggy whips, springing straight up from scaffold branches.) The dead and dying branches might come from gophers or from disease. If there are gophers in your area, look for the mounds and trap them. If disease is the problem, be sure to use dormant spray once a month in winter after leaves fall. (Perhaps the branches that died are the ones that usually bore blossoms.) Fertilize the tree lightly at bloom time, or alternatively mulch the ground in fall with manure—using horse manure from a conscientious horse owner if you can get it. Spread the manure all over the roots from one foot from the trunk to the drip line and let the winter rains wash the nutrients into the soil.

    • I have a now 10 year old Santa Rosa Plumb 2 miles from the beach at the border….
      have had very poor results from not polinating…… an trying to self polinate using a small artist brush this year ….. when I cut it back (topped it) several years ago the tree POUTED for 3 years !!!
      Nothing other than leaves!!! Last 3 years a reasonable number of blossoms but only about 6 plumbs……allmost no bees around….

      now my Freestone peach is so fertile I have to knock off %90 of the tiny green peaches or they would break the branches!!

      • Santa Rosa plum is in my opinion the best tasting of all plums. It needs little pruning. Branches that bear well may continue to bear for many years. Sounds as if you cut off or through the main fruiting branches, thus hampering the tree’s ability to bear fruit. Also, by removing too much healthy wood, you forced the tree to respond by growing more foliage at the expense of fruit. Your tree may never recover from topping or not for many years. The fact that your peach is bearing well is proof you have plenty of bees.

  3. Left a question about my non-fruiting 5 year old Methley plum tree under the wrong rubric (early blight on tomatoes). Sorry!
    I have seen your comments about the Japanese plum trees and always read that you can trim a fast growing plum tree in the winter, so the tree stays at a manageable size. Some of those recommendations came from Dave Wilson and his website (“don’t be shy about trimming your fruit trees”). I planted a pluot tree-Flavor Grenade nearby. Every year, I have lots of peaches early on my Flordaprince tree and am successful with several apple trees from Kuffle creek in Riverside that are growing nearby. I use dormant sprays after I trim. Have I trimmed too much? Should I trim in the summer instead to control size?
    Thanks.

    • Here is the story: A man who lived in a coastal town near me had a magnolia which never bloomed. Granted it sometimes take years before a magnolia will bloom but this one was almost 20 years old. One day the man, an avid gardener, became so disgruntled he picked up a garden hose ad beat the trunk of the tree with all his strength. The next year that tree bloomed it’s head off and it has continued to bloom every year since then.

      Another story: My daughter Wendy and son-in-law Larry bought a house on a cul-de-sac in which every house had a ficus (Ficus rubiginosa) tree in their front yard. None of those trees grew much because each of them were planted in the middle of a vigorously growing lawn which grabbed all the fertilizer and water. Then one day Wendy and Larry came home to find the little boy next door hitting the trunk of their puny ficus tree with a toy sword and, with all his strength, scratching and piercing the bark of the tree with the tip of the sword. They told him to stop, but he had evidently been at it for some time and the bark was severely damaged.

      Within a month or two their tree began to expand in size. Soon it had outpaced all the other ficus trees in the neighborhood. It also began dropping huge amounts of fruit which are sticky and get on sidewalks and get tracked into the house. They bring birds and lots of them and that part is nice but not the mess. So in this case damaging the trunk had a less than happy result. Nonetheless it proves the point: in order to get a tree to bear fruit it is sometimes necessary to bruise the cambian layer under the bark of the trunk. Scientific explanation: The tree get’s the idea it is going to die and so leaves many progeny to carry on after it dies.

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