I have a small greengage tree which must be about 10 years old. In that time I have only had one small sweet fruit from it! At the moment it is covered in blossom, as it is most years, but it’s downhill from there. Is there anything I can do to make the fruit set? Or is it too cold where I live to expect a crop? Thanks!
You should be in the right growing zone for a Greengage Plum Tree.
Your trees needs a full sun location with a good loamy soil that is well draining.
Ph should be in the 6.0 to 7.0 range.
Though this is a self fertile tree you may want to add an additional pollinator to your garden.
Fertilize your tree with a balanced fertilizer. This should be applied annually and a good rule of thumb is 8 oz of 10-10-10 for every year of tree age.
Supplement with nitro-chalk sulphate of potash in February each year.
Every third year add superphosphate.
Mulch the tree with a good compost, but do not place it directly next to the trunk.