Pretty Pittosporum Shrubs
We have had some trees removed to open up a mountain view. As a result, there is a new design opportunity in the Mary Snoddy garden. The steeply sloped area, approximately four acres, has scattered tall hardwoods, a few native Dogwoods, patches of Mountain Laurel, numerous Sourwood trees, and rocks for days. Big rocks. My vision for the future includes a meandering path with decorative plantings on either side, all the way down to the creek. The path will need switchbacks due to the steep slope. Opportunities abound for plants in full sun, full shade, and everything between.
My tree and shrub choices need to be hardy in zone 7 with a tolerance for rocky, acidic soil. They also need to be tolerant of heat and humidity while being deer resistant (a relative term, for sure). I started my plant selection Wish List by scanning photos of other gardens I have visited and admired. From this, I gleaned a small set of shrubs and trees to research. One of these is Pittosporum tobira ‘Variegata.’ I can still remember the wonderful fragrance of this evergreen shrub, a variegated cultivar clad in gray-green leaves with white margins. The clusters of flowers open white but turn yellow when pollinated. The homeowner had allowed the shrub to grown unpruned. It was four feet tall and about the same width.
I learned several things about Pittosporum. First, I have been pronouncing the name incorrectly for decades. It’s not pit-oh-SPORE-um. The correct pronunciation is pih-TOSS-pur-um. It is cold hardy in zones 8-10, although cultivar ‘Mojo’ is more compact and a bit more cold-tolerant. ‘Wheeler’s Dwarf’ is even more compact but less cold-tolerant than others. Mature height for most cultivars is 8-10 feet.
Pittosporum is tough, fast-growing, demands well-drained soil, and makes a good evergreen hedge. It is not particularly choosy about light (full sun to partial shade) or soil acidity. It is resistant to salt, making it a good choice for coastal gardens.
Unfortunately, deer are attracted to Pittosporum and frequently browse it year-round. This trait and its borderline hardiness in my area moved it from my ‘Wish’ list to the ‘Not For Me’ list.
Pittosporum has an interesting characteristic known as ‘sympodial growth.’ This means that the terminal bud will stop growing and lateral buds will keep on growing, giving stems a zig-zag look. This constant forking is also seen in some orchids and Beech (Fagus) trees. For Pittosporum, the terminal bud usually ceases growth because a flower has formed at the tip.
To prevent leaf spots and fungus problems, provide good air circulation, avoid overhead watering, and remove fallen leaves. Note that Daconil®, a common fungicide, is not labeled for use on Pittosporum and will damage or kill the plant. Counter aphid attacks with spray-on horticultural oil.
Pittosporums are easy to propagate from cuttings taken in late summer. Use a talc-based rooting compound to increase success rate.
Clemson University has an excellent fact sheet: https://hgic.clemson.edu/factsheet/pittosporum/