Yellow spots on sides of leaves: 47 yr. old indoor Grapefruit Tee
Dear UofM, My Mother-in-Law passed on the grapefruit tree she planted when my husband was young. I have grown it indoors now for about 11 years. It stands about 8 feet tall. It has been re-planted many times, its current pot height is 17 inches tall and 20 inches wide. Some of its biggest leaves are 9 inches long! It has new growth several times a year; I do prune it occationally it so that does not get more than 5 feet wide. The tree lives in a room with 3 walls of windows, but is 67F in winter due to 15’ ceiling. Late this summer, some of the leaves begin to get yellow spots on just their sides??? (FYI:) she also planted a grapefruit seed when my son was small; that tree is now 13 years old and 6’ tall. She also started a grapefruit seed when our daughter was small, and that tree is now five years old and about 4 feet tall.) I wish there were still Home Extension Groups like my MotherInLaw Ellie has belonged to (for ~55years!) Their meetings sound informative. Sincerely, Mrs. Kathi
Even in the best of circumstances, growing conditions indoors at home are not ideal for grapefruit and other citrus plants. With that in mind, the results you gotten are commendable.
The leaves shown in the photos have some spots but the plant as a whole looks relatively healthy. The following website discusses factors that affect citrus plant health indoors. One or more of the factors mentioned could account for the spots. Although the information at this website has not been prepared by university extension experts, we think it is reliable.
Many Minnesota gardeners who grow citrus plants in containers, set them outdoors during the summer. Summering the plants outdoors usually enhances their health in the long run.
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