Azaleas are a part of the Rhododendron family, so the care instructions for Azaleas and Rhododendron bushes are the same. They prefer acidic soil and grow in Zones 3, 4, 5, 6, 7, 8, and 9. Their bloom time is spring, summer, and fall.
When buying Azaleas and Rhododendron bushes, you will want to make sure the specific plant you buy will bloom in the month you prefer. Some varieties bloom in July, some bloom in March, and some bloom in the fall. While shopping, you will want to make sure you get a plant that is deeper green colored, not yellowed, wilted, or a plant that has dry soil. A simple finger test can be performed by sticking your finger approximately an inch into the soil to test for moisture.
Its is recommended not to buy white-flowered Azaleas in places where the temperature exceeds 90°F in the spring, as the white flowers are more susceptible to heat. If you live in a place that is consistently hot, purchase 3-gallon pots because their root systems will be more established than the 1-gallon plants.
Planting Azaleas and Rhododendrons
Azalea and Rhododendron bushes prefer partial shade. Deep shade and full sun should be avoided. The soil should be at a pH level of 4.5-6 and the soil should have good drainage yet stay moisturized, as well as being rich in humus. If your soil is poor, you can fix this by adding a bit of compost or peat moss. Azaleas and Rhododendrons’ roots are shallow, so you can add mulch on top to lock in moisture. Your plant will tell you if the soil is too alkaline by turning the leaves yellow and appearing unhealthy.
Spring or early fall is the best time to plant your Azalea and Rhododendron bushes, and they should be spaced anywhere from 2-6 feet apart depending on how much they are supposed to grow as they mature. The hole you dig for planting should be as deep as the root ball and twice as wide. When you place your Azalea or Rhododendron, the top roots should be ground level to avoid root rot. After filling half of the hole with soil, water the soil well before placing the rest of the soil. This will help the soil to settle so the roots don’t become too exposed.
If the place you are planting your Azalea or Rhododendron plant consists of hard clay soil, you can dig a wide, yet not too deep hole to plant them in and use a mixture of top soil, compost, and aforementioned peat moss as opposed to the hard clay. This will help with drainage.
Each spring, you should add another mulching of pine bark chips or pine needles 2-5 inches deep. Be careful not to mound the mulch too closely to your trunk, as this can cause the wood to rot. Make sure to leave a few inches around the trunk that is bare of mulch.
Once your Azalea and Rhododendron plants are well established, you can spread peat moss around the base. Make sure to cover the peat moss with a couple inches of mulch so that it does not dry out, as it is difficult to re-wet the peat moss.
Watering your Azaleas and Rhododendrons
During the summer, make sure your plants stay watered if you receive less than 1 inch of rainfall per week. If your plants become too dry, it will affect the amount of blooming you get the following year. An easy way of ensuring that your Azaleas and Rhododendrons get enough water is to install a watering system that runs on a timer. Make sure that the plants do not get too much water, as standing water will rot out the roots.
Another thing that you can do is plant “companion plants” (many people use Impatiens) underneath their Azaleas and Rhododendrons. The Impatiens will notify you when your plants need water by wilting.
Pruning Azaleas and Rhododendrons
Spring-flowering Azaleas and Rhododendrons do not need to be pruned. If you are pruning for height, prune the plants after they flower in the spring. You can cut the stems down to 12-15 inches above the ground if you are severely pruning.
Removing dead or damaged branches and flowers can be done at any time in the year. Make sure not to damage the new buds at the base of old flower stalks, as this will affect your later blooms.