Question
QUESTION: I live in Tracy, California (central valley) and have a 18 to 20 foot Jacaranda in my yard, and although last spring I had the most full and beautiful blossom, this spring there is nothing except a few dry pods on the tree.  

We did experience a very rare frost in the the winter, and the tree may be dormant because of it.  However, when I dig a key in the tree trunk about halfway up, water comes out, and a 3 inch baby tree is starting at the base of the trunk.

What should I do?

Thanks

Karl

ANSWER: Hello Karl - Brazilian Jacarandas are subtropical trees, and grow best in USDA zones 9b-11 (Sunset zones 12,13,15-24)....Tracy is right on the boarder of these zones & just too chilly for this subtropical plant. (Zone 9a/Sunset 14).

They also bloom in early summer (June), & not in the Spring like most other trees.

See figure 2 of this information sheet to see the growth range, to give you an idea of why it is performing poorly -

http://hort.ifas.ufl.edu/trees/JACMIMA.pdf

I think the frost probably killed the outer branches, and the roots are still alive and trying to survive by sending up new branches & root sprouts.  Are the BRANCHES that produce the leaves brown & shriveled?  The trunk may be alive (with the key test you mentioned), but without leaves, so the process of vigorous plant growth has been halted.

Often after a frost die-back (older trees can stand as low as 25 degrees), you end up with a multi-stemmed, shrubby tree or large bush.  Sorry for the bad news - but you can always wait & see what transpires this summer.  I'm afraid the glory of the original tree may be lost for good. ~Marc

---------- FOLLOW-UP ----------

QUESTION: Two follow-up questions. 1) If I wanted to prune it back,
how much should I cut? 2) Would it help putting tree food at the base of the tree?  

Answer
Pruning: I'd wait to see what is dead and what isn't - if it is obviously brown and shriveled, then trim it back to just before the nearest joint where the shriveled part is.  Personally, I'd just let nature show me what is "bad", as dead branches won't harm the rest of the tree - unlike humans!  Any diseases would take a while to work their way into the rest of the tree - at least one growing season.

Plant fertilizer/tree food: Follow the manufacturer's instructions. So, if it is tree fertilized with "stakes", they usually go out at the dripline.  If it is a liquid or granule, then it is applied all over the root zone.

Fertilizer applied right at the base has no extra benefit to the tree, and may concentrate all the "good stuff" in a place where the tree's younger and growing roots cannot get to it.

~Marc