This issue, we have another loyal reader; Rudi Batista, from Sandstone Point, writing in with some questions about problems with their potted citrus trees.
Rudi writes: “I live in Sandstone Point with not a lot of garden space I have (2) lemon trees and (1) lime tree- growing in pots, the area they are in, faces the north. The trees look healthy and get a lot of blossoms but as soon as the fruit form they fall to the ground. Could you please advise me what I am doing wrong? I fertilise 3 times a year with citrus fertiliser”.
Thank you, Rudi, for writing in, this seems to be a relatively common problem with most in-ground citrus and also potted specimens like yours. When citrus bloom they tend to bloom magnificently- all over every branch, but they are sensitive to moisture stress or too much fertiliser. Citrus like full sun and they prefer at least 6 to 8 hours of direct sunlight to produce strong green leaves and abundant flowers. When citrus trees are in flower and starting fruit formation, they need adequate water to form and develop their fruits, even a healthy tree will naturally drop a lot of their fruits as it puts its energy into distributing the available moisture and nutrients, into the fruits- it can actually handle, in the environmental conditions it faces at the time. Citrus use a tremendous amount of energy when flowering and fruiting and sometimes while growing citrus in pots it can be difficult to keep up their moisture requirements. I have planted out, stressed dwarf-grafted ex- potted, citrus plants into the garden, in a sunny position and after their roots found the earth for themselves finally, they became more reliable performers. Sometimes potting mixes can be too dry and coarse, and this will not hold moisture, but if in doubt, you could purchase a simple and cheap moisture probe from the retail garden centre and stick it into your pots to check actually how wet your potting media is. I also found that too much moisture and too much shade will also cause fruit drop as does strong doses of citrus fertiliser. If you can get the citrus trees moisture requirements just right, I find adding some diluted liquid seaweed every 2 to 3 weeks, will keep the plant cells turgid and stable between watering and fertilising. Caution is needed though, as not to fertilise at flower formation as this can possibly cause fruit drop too. Hope this helps Rudi, and thanks for writing in.