Question
My father has a dwarf grapefruit tree in his green house that the leaves have begun to turn yellow then brown and he doesn't know why. The temps avg 100 degrees by day and 50 degrees by night. The tree is planted in a large wooden box with room for growth. The soil is a mixture of sandy soil, horse manure, compost, and black cinder sand. He waters the tree every other day. Until very recently the tree appeared to be in good health it has already bloomed and currently has several marble sized grapefruit. Can you please help us figure out what is wrong with the tree?

Answer
Hi Tanna, A citrus needs to rid leaves in order to put out fruit and blooms.  They will yellow and fall off then flowers and fruit will appear then leaves will come out and look good again.  The only other time leaves turn yellow is with not enough water.  Brown tips on plants too much water.  It is possible that the tree may need to be put out during the summer to get refreshing rain to renew the minerals it looses being stuck in a greenhouse during the winter. There is also a product called atomic grow that can help keep your citrus in tip top shape.   Hope this helps  kathy