Tips for Planting Azaleas in TN
Azaleas can be one of the most breathtaking plants in the spring garden. We’ve all seen a mass of Azaleas in full bloom; beautiful mounds of brightly colored blooms, and thought about how great it would be to have that in our own landscapes. Unfortunately, Azaleas have gotten a bad rap for being difficult to grow in Nashville. While it’s true that there are locales better suited to the Azalea’s specific needs, with the proper soil preparation and planting techniques, we can all grow and enjoy these fantastic shrubs.
Azaleas have a few basic needs that must be met if you want them to thrive. They like moist, but well drained soil. In middle TN, that’s a tough thing to find. Thankfully, it’s not too difficult to create! They also need to be somewhat sheltered from the hot afternoon sun. The ideal planting location for most Azaleas would be under a tall canopy, with bright morning sun and afternoon shade, but they will survive and even thrive in less than perfect placement.
Soil preparation is absolutely key in planting Azaleas. I once heard a weathered plantsman refer to them as “the $3 plant that needs a $5 hole”. While that may be an exaggeration, planting them incorrectly will almost invariably result in a dead shrub and hard feelings.
When planting Azaleas (or Rhododendron, Camellias, Pieris and all other acid loving mountain dwellers), the first step is soil amendment. You will want a loose, organic amendment. The least expensive of these is “soil conditioner”, which is usually finely ground pine bark and leaf compost. The best (and, of course, most expensive) soil amendment for Azaleas that I’ve ever found is called “Woodland Soil Mix”. I find that you get what you pay for with amendments, and WSM can’t be beat for too many reasons to list here. Which ever material you choose to amend your soil with, the same basic rules apply:
- Dig your hole approximately 2 times wider than the root structure of the new plant, and as deep or slightly shallower than the root mass.
- Make one or two piles of the soil you’ve just removed and mix the amendment with that soil thoroughly. The best mixture rate is about 50/50.
- When installing the plant, make sure that the top of the root structure (or the soil level in the container) is just above your existing soil level. In exceptionally heavy soils, the root ball can be planted as high as 1/3 above grade. (See illustration)
- Backfill the hole with your amended soil. You will want the soil level at the edge of your planting hole to be at the same grade as the surrounding soil, and it should slope up to the top of the root ball of your Azalea. This will ensure that water doesn’t pool at the base of the plant, and excess water can drain away from the roots.
Some people choose to add peat and sulfur to their backfill soil with the idea of acidifying it, but 99% of the native soil in middle Tennessee is already acidic enough to keep Azaleas happy. If, however, you really want to go above and beyond, try mixing Mycorrhizae in your backfill. Mycorrhizae are a group of soil born fungi that live in symbiosis with higher plants. They attach to plant roots and take a small amount of sugars from the plant, but repay it with more nutrients and water than the plant’s roots could have absorbed otherwise.
Maintaining your Azaleas is as easy as most other landscape plants. If trimming is needed, it’s best done right after they bloom so the next bloom cycle isn’t affected. Fertilize in early spring to give them a boost for bloom time. My favorite fertilizer for Azaleas is Holly-Tone, an organic fertilizer for acid lovers.
Good luck with your Azalea adventures this spring!