How To Plant And Care For Azaleas
Azaleas are absolutely beautiful while they are blooming, but they probably don’t get used as much as they could because the perception is that they are hard to grow. If you know a few things about Azaleas before you choose to put one in your yard you will probably have a much better success rate than the average person who sees an Azalea blooming, buys it, and just sticks it out in the yard.
Yes, it can be true that Azaleas and Rhododendrons (Azaleas are in the Rhododendron family) can be difficult, but I have had some good success which I will share with you in this blog.
There are many different types of Azaleas. Some grow in the sun like Exbury, but most prefer a shady location. This blog will deal mainly with the shade loving varieties.
Site Selection and Planting
The best location would be where it would get morning sun and afternoon shade. Keep in mind that not all areas that are shade in the summer stay shady in the winter too. Warm sun on a cold day in the winter can cause deadly injury, so make sure your selected spot has the shade in the winter as well. Azaleas like a more acidic soil, so it would also be a good idea to choose a spot by other acid loving plants. If you plant under trees, make sure the trees don’t have a shallow root system. I learned the hard way that if you plant under a tree with a shallow root system you need to water several times a week. Another thing to consider in your site selection is the soil drainage. Azaleas don’t like to be too wet. Don’t even try to plant an Azalea in a low-lying area or in an area that stays wet for long periods of time, it will not survive.
When you plant an Azalea you should not plant it any deeper than the top of the ball on BB or the top of the soil line of a potted plant. It is always good to over dig the hole in width so you can chop up the soil well and put it back around the roots. I am not a big fan of adding soil amendments when planting, but if you have really bad soil you might want to add some peat moss. We will discuss fertilizing later, but you could use a fertilizer low in Nitrogen and higher in Phosphorus (like Root Stimulator) when planting. Phosphorus helps promote a good root system, but it is not very mobile in the soil. It is good to use Root Stimulator when planting and you can pour it directly over the root mass.
(picture: Missouri Botanical Garden)
After planting it's a good idea to put a light layer of mulch around the plant to help keep the root zone moist and cool.
Trimming and Fertilizing
Azaleas start to set their flower buds for the next year about a month after they finish blooming. Because of this you want to do any trimming within three weeks after they are done flowering. I always trim mine about a week after the last flowers are done to be sure I am not messing up the bud set for the next spring. You can give them a light trim with hedge shears or you can use a hand prunner to give them a harder trim. As far as trimming they will take just about whatever you do to them. As an example of this I had an Azalea by my front door that was about 3’ tall and over 4’ wide. It was growing over the walkway, so I decided to do something that I thought was pretty drastic. I trimmed it back to about 18” high and wide. My wife thought I was crazy and had ruined the beautiful plant. It looked like bare sticks for about two weeks. I must confess I was a little worried about what I had done. But one day I noticed little green shoots coming off those bare sticks. I knew I was in the clear from “ruining that beautiful bush” as my wife had thought. This “butchering” took place about five years ago. To let you know how well that Azalea responded, I think I am probably a year away from doing that again to that same plant because it is over the walkway again. (Just a little foot note, I did not plant that Azalea that close to the walkway, it was there when I bought the house.)
I’m sure there are many fertilizers that would work for feeding Azaleas. I have used several over the years and have found Fertilome’s “Azalea / Evergreen Food Plus with Systemic” to be the best so far. As I said earlier, Phosphorus is important in promoting a good root system. A good root system is necessary for good flower production. This particular fertilizer does well in helping Azaleas thrive and produce many blooms. Obviously it would depend on what fertilizer you are using, but you should probably fertilize once every 6 to 8 weeks after the plant finishes blooming up until the end of August.
As I stated earlier Azaleas can be difficult. By following these steps you will hopefully have more Azalea successes than failures. I have been treating my dozens of Azaleas in my yard this way for years. Every once in a while I will have one that does not make it, but for the most part my Azaleas are the highlight of all the plants in my yard.