What is killing my Victorian Box?
Question from Sandy:
Our mock orange hedge which was protecting us from the neighbor below, has been turning yellow and losing leaves. What to do beyond giving it more water? It’s on a hillside, and the earth is compact, so there’s lots of roll-off.
On the other hand, it could be a disease, as the bush next to it is beginning to succumb, leaving our deck a see-thru to yard below, IF this continues! MERCI!
Answer from Pat:
I do not have good news about your Victorian box (Pittosporum undulatum). For the last three years these trees have been dying up and down the Southern California coast where they have naturalized. This African tree is no longer in the nursery trade because it comes up so readily from seeds planted by birds. Thus neither the Department of Agriculture nor the California Extension are interested in finding out why they are dying. I have told the Extension what I think is killing this plant and they could research to see if I am right but there are no funds to cover the research.
The symptoms are that one branch usually dies first. The leaves go yellow, then droop, then go brown and hang on, though some eventually drop off and the branch dies. After that the whole tree or shrub gradually sickens, leaves go yellow and wilt and it finally dies. I think the problem is that a pest insect called the Glassy Winged Sharpshooter (GWS) that is a vector for plant diseases, has injected it with a disease. The reason I think the Glassy Winged Sharpshooter is the culprit is that it is characteristic of the GWS that it specializes on a particular plant before moving on to another and usually one branch dies first, leaves go brown and finally whole plant slowly dies. This insect (GWS) is a sucking insect and when it first came to California it concentrated on grape vines, sucking out their juices and in the process injecting them with Pierces Disease, the symptoms of which are the same as I have described above on pittosporum and that you must have observed on yours. The way California farmers saved their grape vines was to pull out all the diseased plants and burn them and replant their vineyards with grapes grown on disease-resistant root stock. The next plant the GWS attacked was the oleander. They gave oleanders Oleander Leaf Scorch, which is killing off all our large oleanders state-wide. (The dwarf one’s seem to be resistant.) And now I think it has moved on to Victorian box, which is what you have on your bank.
The only Victorian box shrubs that are withstanding this problem are those that are growing in deep, moist, organic soil with plenty of mulch, irrigation weekly and a northern exposure where they have protection from hot afternoon sun. Your only option is to eventually replace with something better, more drought resistant and pest free, such as Australian tea tree (Leptospermum laevigatum), New Zealand tea trees(Leptospermum scoparium), or pink melaleuca (Melaleuca nesophila.)
Our 15 gallon eucaliptus tree was planted about 5 months ago and is showing most leaves are sort of chewed off at the ends, only. There appears to be a small amount of new growth – small spindly twigs. The adjacent ‘soil’ appears to be about 80 % pine tree chips from a tree that was removed and ground up. It seems quite moist and I wonder if the bed was not properly prepared and the tree doesn’t ‘like’ the acid from chip rotting?
Appreciate any advice, Rod
When a tree has been ground up, one should never plant another tree in that location due to the fact that the chips and sawdust are raw, in other words not rotted up. As all my books explain in the opening chapter “What You Need to Know First”, unrotted wood or mulch dug into soil will rob all nitrogen from the soil in order to rot. It is not the “acid” in the chips and sawdust that is hurting the newly planted tree. It is the fact that your new tree cannot get any nitrogen.
If you want to plant in this spot you first must add enough sulfate of ammonia or urea to provide adequate nitrogen to rot the wood shavings and sawdust. Then when the raw shavings and chips have thoroughly rotted it’s fine to plant.
Hi Pat. Thank you so much for your informative website. I appreciate the time
and information you share.
My Victorian Box has just begun to exhibit the symptoms you mention above.
I took a picture of a pest that is on the branch part of the leaves which may
or may not be the cause of these trees dying out. Another factor is that the tree
is sending out hundreds of tiny shoots underneath the tree. I believe some trees do this when they are going to die. I planted one of these tiny sprouts and it has become a shrub now about 4 feet high and wide and isn’t going to become a tree. will have to attach picture by another comment.
Pittosporum undulatum is an invasive tree that has naturalized in coastal zones as far north as Monterey. It is no longer in the nursery trade and is dying throughout Southern California except for few specimens that are surviving due to a sheltered spot, deep mulch, deep soil and adequate moisture. This is just a matter of luck. Once the disease gets growing inside the tree it is just a toss up how long it will live. Some hang on for a long time others not. There is nothing much you can do to save the tree. The sprouts that you find growing below are most likely new plants springing from the seeds. It is a shame these plants are dying since they are so magnificently fragrant in spring. I have already explained the reason for their death. There’s nothing you can do about it other than let the seedlings grow and enjoy the plants you have. If you need a shade tree there are many fine choices.
Hi Pat , My Victorian Box is totally infected by virus !! It’s about 250 yards long ,half which is in full sun is worse for it !!!! Now can you suggest another hedge which looks similar !! The ones you mentioned were a smaller leaf,I would prefer larger leaf , it would have to be full sun, facing west hopefully you can surgest something my email is Lesleyavillard@ hotmail .com I live Santa Barbara so the climate is pretty warm !!!! Looking forward to your reply !!!!!! Lesley villard ,,,,, Santa Barbara
In recent years the substitute plant most frequently recommended for eugenia (Syzigium) and I think that would be true of Victorian box also is Prunus carolineana ‘Brite ’n’ Tite’ or ‘Minus’. You can order P. c. ‘Minus’ at a local nursery. The plants were developed by and are grown by Monrovia Wholesale Nurseries. The leaf is larger than Myrtus communis and even though it is a dwarf, hence the name Minus, it grows to 10 feet if permitted to do so. It grows most compactly in full sun and can be sheared. Make sure gardeners shear it so the tops are narrower than the bottom of the plant, not vice versa as one sees so often and which leads to a loss of foliage lower on the plant.