How to properly prune your Azaleas for peak flower production by - Mark Govan, Host of “Florida Gardening” heard on NewsRadio WFLA
Another year has gone by, and our azaleas have finally finished their show of flowers. Some of them were fantastic, but others were not. You can tell several months in advance, which ones are going to produce the most flowers. Unfortunately, you can also distinguish the ones that have been left to their own and have had little care through the years. Two years ago, I was the one that kept wishing for that massive flower show, but I never took the time to get out there and properly care for my azaleas. Sure, I fertilized them regularly, and I even sprayed them for insects and disease, but this was all too little, too late. The show I was expecting turned into a fizzle with some sporadic flowering, but little to cheer for. In this article, I am going to explain how to trim your azaleas, no matter how old the plants are. Let’s get started.
Azaleas should be pruned every year after their flowers have been shed. Pruning helps your plants to fill in by developing dense lateral branches, which aids in setting more blossoms for next year. You do not have much time to act because the last date you should prune your azaleas is the 4th of July. Trimming your plants after this date, will cut off the buds that have been initiated on the new wood. This can severely limit your flowering come spring.
If your azaleas were like mine, then they have likely been left to their own for years, and they really need a lot of work. My plants were almost thirty years old and had probably never been properly pruned. At over one hundred and fifty feet long, seven feet tall, and eight feet wide, my plants needed some serious help. Dead branches, vines, and leaf debris filled the outstretched arms of my plants. Long branches growing out from the base of your plant that do not have any lateral branching, do little to produce additional flowers. They also collect leaf litter and dead branches. You need to clear this debris, including any vines or grass growing inside your plants before you can make the proper shaping cuts you need.
Once you have removed this litter, and you can see the crown of the plant, it is time to remove any dead, broken, or diseased branches. Use sharp pruning shears to cut these branches back to the base of the plant. You should also cut a few of the oldest canes to make way for new branches to develop from the crown. Depending on how tall your hedge is you will also need to reduce the overall height of the plant by one-third. My azaleas were very old and need a big haircut. By making a reduction cut, you will break the apical dominance of the top branches. Breaking the apical dominance encourages new growth to form from the advantageous (dormant) buds located on the sides of the cut branches. Once the tip of the branch is cut off, lateral branches can form, which helps the plant to fill in. The new growth you see this year will produce the blossoms you get next spring.
After reducing the height of the plant, you will need to decrease the thickness of the hedge. Azaleas left to grow year after year with little or no care tends to grow top heavy. This causes wide growth of the top of the plant and thin or open bottoms. When you trim the sides of your plants, be sure to prune the top of your plant thinner than the bottom. Think about a pyramid shape, large on the bottom and small on the top. You will probably not be able to prune your plant like this on your first attempt, but each year you should train your plants by using this pyramid pruning technique. Over time, your plants will be tall and full of blooms from top to the bottom of your plant. This will give you the best shape and a better growth habit as time goes by.
Now that your azaleas have been properly pruned, it is time to fertilize them with a good-quality Azalea/Gardenia fertilizer. These Acid-building fertilizers help lower soil pH around your plants, which will assist in producing more flowers. Apply three to four pounds of fertilizer every two months for every one hundred square feet of bed space. You will also need to apply a micro-nutritional spray to the foliage of your azaleas at least twice per annum to help them maintain the deep green color, especially in the high pH soils found in the Tampa Bay area. Under-fertilization means you will have weak plants and few flowers. Mark your calendar now of when to fertilize, what time to prune, and stick to it. Monitor your plants for insects and diseases regularly, and over time, your plants will reward you with beautiful flowers come spring.
If your hedge has open spots in it, you can plant new azaleas in-between the bare areas to help your plant fill in. Make sure you purchase the same type of azaleas if you plan of filling in these areas. Remember, azaleas planted in Central Florida need to be planted in the shade. Morning sun is ok, but if your plants get afternoon sun or direct sun, then they will probably not thrive and could possibly die. Mulch can aid you in retaining water around the plants and can help to lower pH as it decays. Be sure to irrigate your plants regularly to maintain a moist growing environment.
I hope your time working in the garden will be rewarded with the satisfaction of flowers come spring. Azaleas will give you years of blossoms if you follow my directions above. Do not try to do everything at once. Plants need time fill in so this process may take several years to accomplish especially on older specimens. Good Luck and Remember, without plants, we would not be here.