What is causing these issues on Pittosporum tobira?

We have 2 Pittosporum tobira planted about 20 feet apart in our front yard under some Oak trees.They were here when we bought the house in 2006.They have always grown beautifully and never had any issues until about a month or so ago.

Shrub #1: I noticed yellow spots on the leaves and they have gradually gotten worse. Recently, I noticed that, along with yellow spots, some of the leaves were turning brown on the tips. There is also what appears to be sooty mold on some of the leaves but you can't really see in the pictures.

Shrub #2: The older growth doesn't seem to be affected (yet), but the newest growth is dying back. The leaf tips and some edges are almost translucent...kind of looking as if they had been burned. There are also some white, near translucent, spots in the center of the leaves. This shrub doesn't have the yellow spots like the other one has, nor have I noticed any sooty mold.

I looked intensely all over both shrubs, on the stems, under the leaves, and on the trunks and see no pests. I showed pictures of Shrub #1 to the owner of a local plant nursery the other day and his first thought was Mealy Bugs. However, there is nothing white, fuzzy, or cotton-like on the bark or leaves of either shrub. I don't see any aphids, spider mites or webbing either. I looked for ants and see no sign of them. I see no scale either. I am at a loss.

Whoever planted these shrubs many moons ago, planted them in pure sand, and I almost never intentionally water them. They get rain water and that is about it, so I know it isn't root rot, nor are they being over-watered.

Any idea what are causing these problems? Any suggestions?

Thanks!

Have you fertilized with anything recently? How about salts to melt any snow? Any other chemicals or pesticides?

If it isnt salt injury or herbicide injury...to me it looks like it could be nutritional. Perhaps potassium deficiency.

I have never fertilized it before because it had always grown without problems. Last month I used Scotts Bonus S granules but I didn't put them within 5-7 feet of the shrub areas. (They are in an island in the middle of the front yard.) Back in January, I did spray them with Neem Oil when I first saw the symptoms developing. I sprayed late in the evening when the sun wasn't on them. We haven't had any snow, so I haven't had to use salt. We did have an unusually cold winter with 2 freezes (1 lasted for 2 days) accompanied by very bitter cold strong winds. I am kind of thinking Shrub #2 has frost/freeze damage.

On shrub #2, should I cut off the dying growth or wait until after they flower?

For shrub #1, the yellow spots are all over it. I don't know what to do with it LOL

Any other suggestions or ideas?

Thanks!

This message was edited Mar 13, 2014 11:14 AM

Just wanted to post an update...I went outside yesterday and decided to scrutinize every inch of both shrubs. Shrub #1 did indeed have very tiny (a little smaller than the lower case "o") white things. Most were found on the bark in the top 1/3 of the shrub where the most new growth was occurring. They weren't in clusters, more sporadic along the limbs, and from the ones I saw, I wouldn't call the shrub infested with them. They had a more flat appearance than a cotton-like one. However, they were small so it was hard to be 100% sure. I couldn't detect any on either side of the leaves, they seemed to be more fixed on the bark/limbs. That doesn't mean they weren't on the leaves, but just that they weren't obvious. Of course it being the time of year for pollen to coat anything and everything, it only made detection that much harder.

As for Shrub #2, I didn't see any of the tiny white things or anything else resembling a "pest", so I really think the damage on it is due to the ice & wintry mix storm we had in January and then again in early February.

Small white flatter than mealy bug sounds like scale.
There are MANY species, and some certainly can look like what you are seeing.

Young scale are very small, and crawl to a new location to start feeding, so you might not notice them right away. This is the stage that is most susceptible to pesticides.

When they breed many scale protect the eggs under the mother's waxy shell, so spraying a short lived pesticide has no effect on them. When the eggs hatch the young crawl away from the mother, but the pesticide has washed away or degraded so it is safe for them.

Scale and many other sucking insects can make the yellow spotted damage you show in some pictures. They do not do the burned edge sort of thing that shows in other pictures.