How to reduce plum harvest?

Question

Is there a time-efficient (possibly chemical) way to reduce the number of plums generated during one season - while keeping the tree healthy?

The intent is to keep the tree as a source of shadows, while avoiding the work of removing plums from the lawn.

As an avid consumer of plums, your question confuses me. – Ian MacDonald Aug 30 '19 at 13:09 — Ian MacDonald, Aug 30 '19 at 13:09

score 1 · Answer 1 · answered Aug 30 '19 at 11:08

Two things to consider:

Plums are mostly insect pollinated; there is some wind pollination and some self-pollination (see this study for example). So if you can prevent insects from visiting, say by draping the tree in a barrier of some sort while the flowers are open then pollination will be hindered and fruit production will decline.
Plums make good wine and preserves. Perhaps a local wine club would be happy to send volunteers to pick up the harvest and cart them away. No work on your part, the tree remains a source of shade and you don't need to pick up the fruit, it just disappears and you might benefit from a few bottles of plonk.

Re "volunteers" to pick the harvest, a friend has a couple of old and large plum trees. One year some thieves turned up and picked the entire crop, while they were away on holiday! Several neighbours saw them at work (which took most of a full day) but assumed they were supposed to be doing the job, since they looked like professionals. — alephzero, Aug 30 '19 at 11:46

score 1 · Accepted Answer · answered Aug 30 '19 at 12:37

There are some regulators, but it seems the effect depends on climate, so not very consistent. And this is done to reduce fruits, so that the plant have larger one, and with more sugar. Maybe it is not what you want. You should ask your local agriculture shop: products and way to use depends on region/climate.

But the plants want to produce fruits, so next year the tree will try harder.

The easy way: ask people near you if they are interested on harvest them. Cheap and most effective.

How to reduce plum harvest?

2 Answers2