Herself's Houston Garden

Conservation through cultivation

Japanese Pittsoaporum



When I first moved to Houston it was like being in an alien landscape. Oaks, maples and pines were clearly oaks, maples and pines but the bark, the leaf shape even the structure of the plants was just slightly tweaked from those in New England.

So when I saw the pittsoaporums I thought ‘Aren’t the azaleas different down here?’. And since it was May when I first arrived I patiently waited for the next spring to see what colors the flowers would be.

But of course there were no flowers and my azaleas were not azaleas but pittsoaporums, something we don’t have in New England. I saw some again in Hawaii and almost didn’t recognize them. The species common there grow about twice the size with leaves about three times the size of the ones in Houston.

While Japanese pittsoaporum is very slow growing other varieties it can grow quickly to form small trees reaching up to 15′ in height and spread. Japanese pittsoaporum wil only reach 2′ to 3′ in height.

This plant is heavily used by contractors and you’d be hard put to find a home in Houston that didn’t come with pittsoaporum installed in the landscape.

Flowers are small, white, and not really noticeable in the early spring except for the nice fragrance.

Leaves are thick and leathery. They grow in round patterns about the stem and are extremely densely packed. Plants remain evergreen.

It will grow in full sun to shade, and prefers slightly moist soil. It is drought tolerant once established, but will rot quickly in soils that are always wet. It prefers an acidic soil, but will usually tolerate a more basic soil. These are good along the coast since they do not mind salt spray.

They are very sensitive to root rot and fungus. And fungicides often cause the death of pittsoaporum. If there is a fungus problem cut the effected area back at least 6″ below damage. All you can do is try to keep it happy and hope it fights it off on its own. I lost two during a wet, rainy spring.

I lost some of these during a rainy spring, the remaining ones during Ike.

pittsoaporum dying from root rot fungus during wet spring

They are also sensitive to magnesium deficiency in our high pH soil in Houston. Leaves yellow at the edges when this happens. So fertilize lightly and often.

Plants grow rapidly when young, slowing as they reach mature size.

Watch for aphids and scale on the underside of the leaves. Mealy bugs may also attack this plant. Mites will be seen as fine webbing all over your plant.

This, and several other plants are also known as ‘mock oranges’. There are over 1,000 varieties in this species.

Best time for transplanting these is very late spring or very late summer, just on the edges of the summer. Propagate by cuttings.