Growing Rhododendrons in Containers
The rhododendron is a massed floral plant, growing best in up to 50 per cent shade and reaching a maximum height of about 30 inches. Rhodendrons thrive in containers with specific attention to watering and feeding. Other criteria to ensure the success of your rhododendron containers include light conditions, soil composition and moisture. Follow these guidelines to achieve maximum blooming and beauty with your potted rhododendrons.
Step 1: Find the Best Site for Your Rhododendrons
Put the rhododendron containers in a spot where they will get primarily north or eastern light exposure. If you can give them dappled shade from a mature evergreen tree with well-spaced branches, this will be beneficial for the rhododendrons to bloom. Do not place them in direct sunlight, as this will scorch the leaves and flowers.
Step 2: Choose Healthy Rhododendron Plants
The rhododendron stock you purchase should be between 8 and 16 inches in height so they can overwinter well. Purchase them as early as possible in the spring while they are still dormant, as they will handle the transition to a container more effectively at that time.
Step 3: Select a Suitable Container
The first container for a rhododendron should be no more than 8 inches high. Providing good soil drainage is crucial to their growth and longevity. Make plenty of holes in the bottom of the container to prevent standing water in the pot, which will cause root rot and mold diseases. You can plant your rhododendrons in a simple pot and install them in larger ornamental containers to enhance your garden landscape. Put down a layer of gravel in the bottom of the outer pot to aid evaporation.
Step 4: Compile the Ingredients for the Potting Soil
Use a purchased potting soil when establishing rhododendrons in containers to avoid the risk of insect infestation and exposure to mold spores. Rhododendrons prefer a slightly acidic soil, so add 2 parts peat moss to 1 part potting soil, plus 1 part sand and 1 part perlite.
Step 5: Plant the Young Rhododendrons in the Containers
Be sure to soak the root ball of the rhododendrons before you plant them in the container pots. This enables them to untangle more effectively and search for other sources of water and nutrients.
Step 6: Ongoing Care and Maintenance
Rhododendrons in containers depend on regular feeding and watering from you. Water them only when the soil has dried out to about 3 inches down from the surface. Feed regularly with a slow-acting plant food monthly, or with a soluble fertilizing composite every two weeks, according to the producer's directions.
Step 7: Winterizing Rhododendrons
Protect your evergreen rhododendrons from the harsh south and southwest rays of the sun in winter. Shade them with a high burlap screen at least 60 inches tall, or place discarded Christmas trees in a semicircle around the plants. Do not cover the rhododendrons entirely, as they need some luminosity to promote bud formation. Shelter them from gusty winds to prevent drying of the leaves and branches.