Hi Tui, my 50 year old plum tree hasn't fruited for 5 yrs, it flowers and then the fruit that set turn from dark green to yellow and fall off. Over the years I have had it pruned, sprayed, fertilised, and watered to no avail. Please advise. Kelvin.

Hi Kelvin, is there anything that may have changed in the last 5 years that may have affected the tree? Could it be in more shade than before, have weather patterns changed, does it require a pollinator? The fact that the tree is flowering is good, not holding the fruit would suggest incomplete pollination by bees, this could be caused by weather patterns changing, bees don't fly in wet or windy weather. If you have space, look at planting a suitable pollinator for your tree, maybe there was one in the vicinity that is no longer there. Try spraying a sugar solution on the flowers to attract bees to the tree to improve pollination. Has there been a sudden change in temperature at the time of flowering, frost and sudden temperature change can damage flowers at a critical stage. Otherwise, you sound like you are doing all of the right things. Continue feeding the tree in spring and again in late summer, regular watering and mulch around the base to help conserve soil moisture. The Tui Team.