flowering trees-Rose of Sharon

July 7, 2021

Lovely, But A Little Misleading

It’s not really a tree, it’s not a rose and the name is a misnomer. But it is lovely, with large blooms and choices of color and easy to deal with too. Probably the Rose of Sharon’s best feature, or at least its special feature, is that flowering trees tend to all bloom in the spring. This is a late summer and fall bloomer. These are hard to find, and a major pleasure of the garden is to continue the succession of blooms. The most enjoyable gardens always have color, always something in bloom.

“I am the rose of Sharon, a rose of the valley

-The Song of Songs

Will It Grow For You

It will grow in gardens in a wide geographical range, in hardiness zones 5-8. Use this map from the USDA to find your hardiness zone. Put in your zip code or just look on the color-coded map.

How You Can Use It

Because it flowers in late summer and fall, just when the color is needed, it gives us options. With its size and many color choices, you can fill in gaps in the garden. You can establish the continuity of the blooms you need in the garden. Also, it is a temperate climate plant.

Rose of Sharon is Hibiscus syriacus, a cousin, if you will, of the much flashier and varied Hibiscus rosa-sinesis, a more tropical plant. You can use the tropical in loads of ways in your summer garden in northern climates and bring it indoors or treat it as an annual. In many climates, you cannot just leave it in the garden, under the snow. The Rose of Sharon is just fine there.

What Is It Really?

Botanists classify it as a large shrub, but the plant is easily pruned as a single trunk tree of about 8-12′ in height. You can them wherever you need them, in groups, in beds, as hedges or privacy plantings (although deciduous), They can work as specimen trees in small spaces. The name, of course, references the biblical rose and the middle eastern location. The plant, however, comes from China.

Its tropical cousin is Hibiscus rosa sinensis, The rose of Sharon’s name is Hibiscus syriacus, which implies an origin in Syria. They both are native to China and have spread throughout the world.

How To Plant The Rose Of Sharon

Select a location, preferably in full sun or light shade. Dig the hole 2 to 3 times as wide as the root ball. Amend the soil if needed, Place the tree carefully in the hole and fill 1/2 way and water to eliminate air pocket. Fill and mulch. Do not allow the mulch to touch the tree and ensure that the mulched area is wide enough to protect the tree from damage from lawn care equipment.

How To Prune The Tree

Here are the steps in pruning:

  1. Prune in winter or early spring
  2. Cut off dead or damaged limbs
  3. Remove crossed or rubbing branches and any growth visible at the base
  4. Cut the tree to 2/3 of its initial size

Water And Fertilizer

Water the new plant three times per week to permit it a good start. A weekly watering should be sufficient for the mature tree. Fertilize in spring with 10-10-10, or 10-20-10 fertilizer. Feed again in midsummer.

Soil

The best performance from this plant is from well-drained, rich, and slightly acidic soil. It is reasonably accepting of soil variation but not overly wet or dry soil.

Pests And Diseases

There are two very similar diseases that affect this plant. Here is a little chart. Notice that it is sometimes hard to distinguish between them and that the solution in both cases is cleanliness and steady maintenance. I am not a botanist but I think I get the message.

Bacterial Leaf SpotFungal Leaf Spot
Featuresdamage tends to be angular, often has a yellow margin, soft rot, may have a foul odor, often oozes.Similar spots have red, brown, or yellow margins. leaves die back. Infects a wide range of ornamental plants.
Causesdebris from damaged plants, excess wetness, can be from overhead irrigation. You can spread by touch, tools, or irrigation. Waterborne, need moisture to infect, Spreads in infected plants and stressed plants.
Managementclean planting materials, minimize wetness on leaves, copper-based fungicides.lower humidity, improve ventilation, minimize leaf wetness, clean tools, and materials. Fungicide.

Good daily management is important, be observant, act promptly and seek good advice. Avoid rookie mistakes like missing watering cycles or watering in heat or before a damp evening.

Use your County Extension Service. Ask for help from someone with expertise in these or similar appearing diseases. You can try your garden center or botanical garden. (Bring them photos unless they specifically want to see the leaves.)

Some Common Pests

Aphids-identify by curling, stunted leaves, and sticky substance. You may see the tiny bodies or the substance. Sometimes they can be removed by water pressure. Neem oil or horticultural oils will work also.

Root-knot nematode signs are the plant drying up or wilting. Knots or galls, form on the underground roots and prevent the plant from taking water or nutrition.

Summary

When planted in an appropriate location and maintained in circumstances that avoid stress this should be a versatile low maintenance plant. It should also have the effect of solving the problem of seasonal blooms while giving you something beautiful to look at. If you like the idea of flowering trees for your yard, here are some more. They are sorted by climate, temperate or tropical.