(1) Plum Tree losing fruit and (2) Ground cover

(Question)

 

1. I have an eight year old plum tree that produces a lot of fruit, all of which drops to the ground. I spread some fertilizer last spring near the base of the tree, but that didn’t help. What can I do to stop the plums from falling? Should I put more fertilizer, and if so, how much and in what manner?

2. My neighbour’s house is tall, blocking direct sunlight for much of the day between my house and his. Consequently, grass doesn’t grow very well between our houses where there is a 2.5 m corridor. Many people place stones in these corridors, but I’d like to keep that area green. What could I grow in that space to keep it green? Would clover be a good option? Does it need maintenance? Will it spread in the grassed area adjacent to the corridor?
 

(Answer)

Thank you for your inquiry. There are a number of reasons for fruit drop however, without additional information such as the variety of plum tree, how often the tree is watered and fertilized, and the type and amount of fertilizer that was added it is difficult to give a specific answer.

The following is a list of possible reasons for fruit drop:

1) Pollination Failure: It is normal for unpollinated fruit to drop to the ground. Small plums form at each flower but drop before becoming mature. Most varieites of plum trees require cross pollination by a different variety of plum. Both varieities of trees must flower at the same time and be planted close enough together for cross-pollination to occur. Insecticides should be avoided before and during flowering.

2)June Drop: This is a natural thinning process by the tree that occurs if the tree has tooo many fruit. Competition for nutrients causes the tree to shed some fruit. This natural fruit thinning benefits the remaining fruit, which develop into larger better quality plums.

3) Weather Problems: If the weather is too cold when the blooms appear, bees may not be available for pollination. Or, pollinated flowers may form fruit but the fruit fails to develop when temperatures are too cold or if there is insufficient sunlight when blooms appear.

4) Insects: The plum curculio weevil attacks many kinds of stone fruit including plums. Damaged fruit drop early and will appear pockmarked. Cavities appear where the female curculio drilled a hole and laid its eggs. The following websites contains detailed infromation on the curculio weevil and it’s control:

https://nysipm.cornell.edu/factsheets/treefruit/pests/pc/pc.asp

https://www.agf.gov.bc.ca/cropprot/plumcurculio.htm

5) Diseases: Plum trees are susceptible to fungi, bacteria, viruses and nematodes. Damage to the tree may cause a decline in fruit quality and viability. As a result, the fruit may drop pre-maturely. Check the tree for signs of damage, tumor-like growth, discolouration, yellowing leaves and defoliation.

If the fruit trees are grown in a good garden soil, most trees will not require fertilizer before they bear fruit  in the third or fourth year. Once in production, fruit trees benefit from a light application of fertilizer in early spring each year.A good rule of thumb for trees grown in an average lawn is to apply 300 g a 10-10-10 fertilizer mixture, per year of the tree’s age. Manure can be substituted for commercial fertilizers.

You may wish to refer to the following websites for additional infomation:

https://www.omafra.gov.on.ca/english/crops/facts/fruit_home.htm 

https://www.omafra.gov.on.ca/english/crops/gardbk/gh-ch5-4tdr.htm

A ground cover is a plant that will cover the earth with dense, low growing foliage which inhibits the germination and growth of weeds. There are a number of  important factors that one must consider when choosing a ground cover: water, amount of sunlight and type of soil. The area between the houses receive both little light and water therfore it would be best to choose a groundcover which is able to grow in dry shade. Clover requires full sun to germinate.  Vinca minor (periwinkle), is a broad leaf evergreen with narrow pointed, glossy dark green leaves over a wide -spreading shoots. Hedera helix (Ivy), is another ground cover that will thrive in dry shade. Both these ground covers once established will spread into the surounding turf if left unattended. Another alternative is to plant a variety of hostas. These perennials do well in shade however, they do require a fair amount of water. You may like to refer to our Gardening Guides entitled: Broadleaf Evergreen Groundcovers for additional information.

Happy Gardening.