Mailbag: Leaky mimosa trees, irrigating citrus

Q: I have a beautiful mimosa tree that is leaking sap in the trunk and now it’s spreading to the large branches of the tree. Green Acres wasn’t able to help me. I know this is a gardening website but I thought I would ask if you have seen this or know of a professional arborist.

— Pamela

A: It could be normal or it could be the sign of something bad. Some trees (including mimosa trees) leak sap as a way to relieve pressure inside the tree’s vascular system, especially during extremely hot weather (which we’ve had).

Are the tree’s leaves still green? If so, then the tree is probably fine. But if the tree’s leaves are also turning yellow and dropping, then the leaky branches may be a sign of fusarium wilt, the same fungal disease that kills heirloom tomatoes and lurks in soil all over Sacramento.

Is it clear, sticky, normal sap or is it frothy or smells fermented? Normal sap is OK; frothy or alcoholic-smelling sap is not.

The UC Davis Arboretum has mimosa trees (also called silk trees) and may have an expert who can answer your questions. Also, Sacramento Tree Foundation experts can be very helpful. They also have a list of certified arborists they can provide, at http://www.sactree.com

Q: Do you know if there’s a way to deep water 2 trees at the same time?  I have a lemon tree and an orange tree very close together and wondering if I can buy something to water them at the same time.  I thought I saw a “Y” shaped hose for gardening, but all I can find online are hoses for washers.

Thank you!

— Maria P.

A. For watering your citrus trees, I’d suggest this: Attach a y-shaped shutoff valve (available at big box stores, hardware stores and nurseries) to the end of your main garden hose. Then attach soaker hoses (or whatever you prefer to use) from each side of the Y and run them to your trees.

Remember that the roots of citrus trees run out past the drip line (farthest edge of the leaves) so loop the soaker hose out there, not right next to the trunk.

Hope that helps. Happy gardening!

— Kathy Morrison