Question
hi dr. vann-
we have a line of tall wax leaf privet in our yard that are becoming sparse.  i'm not sure if we have the japanese variety or lucidum.   we live in southern california.  i believe the plants may be around 20 years old.  they are currently around 11- or 12-feet tall.  they used to be very hardy and lush with deep green leaves.  but over the last couple of years, they've thinned out.  some of the leaves are mottled with lighter green-yellow spots.   i've gotten conflicting information about nearly everything:  how tall they should be (i've seen from 8-10' up to 25'), how much water they should get (light water once a week to no water except in our dry summers).  last summer i topped them in the hopes that they would become thicker, but there's been very little new growth.  one of the plants has some branches that have completely died out (at the top and bottom).  fyi:  we also have gophers in the yard.  i've heard they could also be contributing to the problem; however none of the trunks seem to be wobbly (which is what's happened when we've lost smaller plants to them).

do you have any thoughts as to what the problem could be?  also, what qualifications do i look for if i want to hire someone to look at these?  do i need a horticulturist or will a landscaper have the appropriate knowledge?

thanks for any information you can pass along.

Answer
Frances:
These are quite hardy plants. For some good advise you can contact the local county Extension there in your county- usually located in the county courthouse. Check in the phone book.

You may wish to consider collecting and having a soil sample tested for nutrients.  This test is often a free service.  This test may ID any potential deficiencies in the soil that is required for vigorous growth. Also, there may be a staff member that can make a house call to see your plants and offer unbiased advise.

Regards
Steve