This slow-growing shrub loves shade. Its shallow roots must be kept cool and moist in well-drained soil that does not hold water or become boggy. Happy rhododendrons can reach heights over 8 feet when mature. It is an ideal plant for woodland gardens, particularly those with excessive shade. Do note, though, that all parts of this rhododendron shrub are poisonous to humans and pets. The Catawba rhododendron grows best in shaded areas because its sensitive root system does not like to be exposed to heat. Its roots should be kept cool and moist, but be careful to avoid wet feet—good soil drainage is essential to avoid root rot. Moreover, this shrub’s root system is shallow, so the roots can be easily damaged (for example, by weeding too vigorously around it and accidentally striking its roots with a shovel). Some of these concerns can be addressed by applying 3 inches of mulch around your Catawba rhododendron. A layer of mulch will:
Reduce the amount of heat that permeates down to the root system Help retain moisture Cut down on weed growth and furnish a protective buffer between you and the root system
Prune your Catawba rhododendron just after it is done flowering. Tardy pruning could cause a reduction in flowers for next year.
Light
Give Catawba rhododendron a little morning sun at the northern end of its range. At the southern end of its range, give it full shade.
Soil
Make sure that the soil for these shrubs drains well. If the soil does not currently drain well, amend the soil with organic matter.
Water
Catawba rhododendron has average water needs, but try to keep its soil evenly moist without making the soil overly wet or boggy.
Temperature and Humidity
Catawba rhododendrons prefer cool temperatures and high humidity.
Fertilizer
Fertilize Catawba rhododendron in spring yearly by working compost into the soil.
Pruning
Start by pruning off dead or damaged branches just after your rhododendron has finished flowering. Next, trim off any branches that are sticking way up above the rest, thereby spoiling the overall shape of the bush. Yearly pruning will promote a more compact shape.
Propagating Catawba Rhododendron
These shrubs can be propagated using cuttings in late summer or early fall after new growth has begun to harden. Here’s how:
How to Grow Catawba Rhododendron From Seed
Growing rhododendrons from seed is time-consuming, but it can be done. Here’s how:
Overwintering
In temperate areas, no winter care is needed. However, if you live in a region that experiences freezing temperatures, it’s a good idea to wrap your rhododendrons in burlap to protect them.
Common Pests and Plant Diseases
Black vine weevils and thrips are the most common insect pests of rhododendrons. These shrubs are also susceptible to a bacterial disease called crown gall. Fungal diseases that may affect rhododendrons include various cankers and gray mold.
Common Problems With Catawba Rhododendrons
Yellowing leaves often indicate soil that is too alkaline; rhododendrons need acidic soil. You can amend alkaline soil with various acidic additives like minerals and fertilizers.
