We have a potted, indoor growing grapefruit tree, which we successfully grew from a seed, about 10 years ago. We're concerned about it. It's gone into a strange stage -is dripping clear sticky sap from the leaf stems. It's also stopped producing thorns. Otherwise it appears healthy. Has anyone else had an experience like this?
Re: How Might I grow a Grapefruit tree? You may want to check for scale on your tree since they produce honeydew which fit the description of sticky sap. Look for small bumps/shells on the stems and leaves; they're commonly brown or grey. Perhaps the lack of thorns in the new growth is a good sign as thorniness is typically a characteristic associated with a juvenile tree. It has been mentioned many times in these forums that a seedling grapefruit tree grown indoors won't mature for many years if ever. However some have reported having success.
I agree with Junglekeeper on both counts. The "sticky sap" is more than likely the honey dew which is commonly discharged from insect, probably either scale, aphid, mealy bug or white fly. None of these insects are all that harmful to your tree if controlled quickly. The loss of thorns is also a positive sign, as your tree could be changing from a juvenile tree to a mature tree. If this is indeed the case you could begin to see some blooms developing in the future. However a fruiting grapefruit tree is a rather rare situation, when the tree has been grown indoors for 1/2 of each year and also grown as a container tree all of its life, I am very interested to know two items: (1) how tall is the tree, (2) what size container is the tree growing in? Thank you. - Millet
The tree is about 7 ft tall and is in a round plastic pot 10 inches tall by 1 foot high . There are 3 trunk growths with the lagest beeing about the size of a large thumb . I have now taken a closer look at the " sap " driping of the leaves and it looks like your brown scab theory is correct . There are many tiny brown scabs on the trunk and branches . The tree was never transplanted or fertilized for it's whole life ( about 17 years ) Once or twice a year I mixed a spoon full of brown sugar with the weekly watering . It seamed to like this as it was growing and healthy until this scab attack recently . Other wise the plant's trunk and branches are strong and healthy and it stands near a south facing window . It is more tall than bushy as it has been pruned often because of space available.
Evidently your house water supply must contain enough dissorved essential elements to satisfy the trees nutrition requirements. You need to eraticate the scale, before damage to the tree. First would be defoliation, and eventually the tree's death. Use the search function on this forum, as there is tons of information concerning the control of scale. Good luck to this tree. - Millet
This was great information, my 23yr old lemon tree (indoor) has been dripping sticky sap as well and I would'nt have thought to look for bugs under the leaves but they are there.
Here is my input on the sweet secretions from the pests on underside of leaves you can squish off. This sweet honeydew is excrement that is put out by the aphids to attract ants to protect them from predators as they ruin our citrus trees. LOL! I have hand washed hundreds of leaves over the years to remove the pests and honeydew but never had ant issues indoors. Mandarins are very prone to this.
