Q. Tania of Thousand Oaks writes: "Last spring we planted three jacaranda trees. When they were planted, the leaves looked very green, but at the moment they are almost yellow. I love my trees, and I'm worried that I will lose them. What am I doing wrong?"

A. This is a question that I get quite often around this time of year. Most jacaranda trees in Conejo Valley naturally lose their leaves every year in March or April. It's just what they do. I know it sounds strange, but while most deciduous trees in Thousand Oaks are just getting their new spring leaves, jacaranda trees are losing theirs. You look around at all the sycamores, alders, oaks and ash trees, and they're getting new green leaves right now. But there it is, your jacaranda turning yellow and dropping all of its leaves.

Some jacarandas will get new leaves almost immediately after the old leaves drop. What usually happens though is the tree will stay barren of leaves for about two months and almost look dead. Then usually around June, the tree will blossom out with beautiful lavender flowers which will stay on the tree until they finally create a colorful carpet everywhere under the canopy. As the flowers drop, new leaves will appear and stay on the tree until next spring, when it again tricks many people into thinking that their tree is dying.

Q. This question comes from Bob in Sunset Hills about his olive tree that's about 38 years old. He writes, "Over the last several years some branches have died off entirely and branches that do leaf seem to do so 'pom-pom' style only at the ends of the branches."

A. It's normal for there to be many small dead branches in the interior of olive trees because of how thick a healthy tree can get. Proper thinning of the tree to allow more sunlight to reach the inner branches usually takes care of the problem.

What you're describing as whole branches dying is something completely different.

There is a disease that infects olive trees called verticillium wilt fungus. Once this fungus infects a tree, it may kill just a few branches or methodically move throughout the entire tree. This disease kills by blocking the vascular system that transports water up into the branches and stems of the tree. The only way to know for sure if your tree has this disease is to get a sample of tissue tested at a diagnostic laboratory. The bad news is that there's no cure for verticillium wilt. Even if the tree is diagnosed with the infection, there's nothing you can do about it. My suggestion is to give your tree proper irrigation and apply some slow-release fertilizer within the drip line area and see if it responds. Every tree likes a little TLC, and it just might help.

Dave Mortimer is a certified arborist with more than 30 years experience in the tree care industry. E-mail questions to dmortimer@theacorn.com.