My azaleas are done for the year, and they were spectacular. Now I need to know what I should do to make sure they’re healthy and spectacular again next year.
A gardening friend of mine has always said, “To have beautiful flowers next spring, get your azaleas pruned before the Fourth of July.” And even though you may not find that advice in any scientific journal, it’s not a bad way to remember spring pruning.
Before grabbing your shears, however, decide whether pruning is really necessary. Has the plant outgrown its space? Is it being shaded out by surrounding trees? Has it lost its natural good-looking symmetry … lost its vigor? If the answer is no, put the shears down and settle for judiciously cutting out or back the occasional overzealous branch.
If pruning is necessary, prune azaleas after the flowers have passed and before the plant sets its flower buds for next year. That makes it late spring or early summer for pruning. Since I’m not interested in pruning anything when June’s summer heat sets in May is my preferred time to get this chore done.
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As with pruning any shrub, the goal is to improve its blooming, help develop a full, attractive plant and to ward off diseases. To do that, start with removing the damaged, diseased, dying and dead branches.
If your plants are older and have gotten a little leggy, you can prune out the overgrown branches by cutting them all the way to the main trunk or to another lateral branch. This thinning will allow light to penetrate the shrub, encourage growth on interior branches, and improve air circulation. Actually, you can do this kind of pruning at any time of the year without losing a lot of spring flowers. If your plant is particularly leggy, don’t grab the chainsaw and cut it all back at the same time. Do it gradually over a number of years to reduce any stress to the plant.
Next, consider fertilization. Our sandy Florida soil makes frequent, light applications of fertilizers necessary. Use a complete fertilizer specially formulated for azaleas and other acid loving shrubs containing micronutrients. Fertilizers with an analysis of 12-4-8 or 15-5-15 (referring to the ratio of nitrogen to phosphorus to potassium, and always appearing on the label) should be applied during each season — spring, summer, fall, and winter. Apply approximately ¼ pound to a mature plant or ¾ to 1½ pounds per 100 square feet.
You have probably heard or read that dumping your used coffee grounds on your azaleas is good for adding acid to your soil. Well, that’s not exactly the best practice and may actually be detrimental to your plants. Azaleas grow best in an acidic soil with a pH of 4.5-5.5. Too alkaline, and azaleas can’t absorb adequate iron from the soil. Not enough iron and the plant can’t absorb adequate nutrients, and the leaves yellow making it difficult to make food for the plant.
Used coffee grounds are acidic and are a natural means of maintaining low pH levels. But, soil pH levels aren’t a fixed number, or static level of acidity vs alkalinity. It can and does change over time, sometimes daily. Unless you’re prepared to check the soil’s pH regularly, there’s no way of knowing whether or not the soil is still in the plant’s preferred pH range. This practice can also compact the soil over the azalea’s very fine roots.
Consider instead adding your coffee grounds to your compost pile/bin where its acidic quality and coarse texture will improve your compost. If you haven’t gotten around to starting a compost bin or pile yet, check out all the benefits of, and the easy steps to making and using your own compost at UF’s publication, “Compost” at https://sfyl.ifas.ufl.edu/sarasota/natural-resources/waste-reduction/composting/.
Once you’ve pruned (or not pruned) your plant and taken care of fertilizing, it’s time for mulch. As already mentioned, azaleas have very fine and shallow roots. So in addition to all the benefits mulch provides any plant, it is particularly important for azaleas as a protection for the delicate roots. (For more Florida Friendly guidance about mulch and other topics, go to https://ffl.ifas.ufl.edu/about-ffl/9-principles/principle-4-mulch/). For mulching material, use 3- to 4-inch layer of pine straw, pine bark, or oak leaves (all inexpensive or even free), or your now coffee ground laden compost, to help acidify the soil on the top layer.
For established plants, azaleas don’t need much irrigation except during periods of hot, dry weather when they should receive about 1 inch of water every 10-14 days.
That should do it. The basics for keeping your azaleas healthy and ready to make another spectacular display next spring.
Paula Weatherby is a Master Gardener Volunteer with the Duval County Extension Service and the University of Florida/IFAS. For gardening questions, call the Duval County Extension Office at (904) 255-7450 from 9 a.m. to noon and 12:30 to 3:30 p.m. Monday-Friday and ask for a Master Gardener Volunteer.