Azaleas – FAQ

Those with questions on azalea bushes are searching on the internet for one of two reasons: to find them (to see or buy) or to figure out how to grow them better. So here’s your chance to read answers to your most commonly asked questions. As time goes by, additional questions from gardeners will be added to the list. So check back often.

1. When should I fertilize my azalea bushes?

2. How do I prune my azaleas? When should I do it?

3. How do I transplant my azalea?

4. How do I take cuttings from my azaleas?

5. How and where should I plant my azalea?

6. Why are the tips of my leaves dying?

7. Why do my leaves have white powdery spots?

8. Why are the centers of my leaves turning brown?

9. My flowers are all slimy and fall off, why?

10.Why do the leaves on my azalea bushes have yellow veins?

11.Why has my plant has wilted and partially collapsed?

12.Why are my leaves burned on the outside edges?

13.Why do my leaves have yellow/pale spots?

14.My leaves are swollen and all curled strangely. Why?

15.What is causing dead spots on my leaves that eventually turn black?

16.What is eating my leaves and making my plant wilt?

17.My leaves are speckled and some are gray-colored. Why?

18.Why are my leaves a bronze/gray?

19.I have bump-like bugs on my leaves and stems. What are they?

20.My leaves are being eaten, but my azalea’s health seems fine. Why?

21.Why are my branches turning brown and dying?

22.My plant won’t bloom. Why?

23.Where can I buy azaleas on-line?

1. Azalea bushes should be fertilized after spring bloom. This encourages bud development and foliage production. For more information read our page on fertilizing. Return to top of page.

2. Azalea bushes should be pruned after they have finished blooming in the spring. Certainly before early summer. Waiting too much longer will cause your azalea bush to lose forming buds for next year’s show. Generally tip-pinching should be enough to keep your azalea bush well-formed, but if you need to do a more extensive pruning job, read our section on pruning azaleas. Return to top of page.

3. Transplanting azaleas should be done in the fall or while dormant, if possible. Azaleas have shallow roots, so it is usually not too difficult to obtain the entire root ball. Dig down at an angle next to the plant’s drip-line about 6 to 12 inches deep (deeper if you have a really large plant). Then cut across the bottom of the azalea bush. Move it to it’s new home and mulch it well. For complete information on transplanting, transplanting azaleas read our transplant page. Return to top of page.

4. Cuttings are generally taken in the early summer when the new growth has had a chance to stiffen up a bit. Take cuttings from the newer growth that comes off of an existing woody stem. I recommend using a rooting hormone before planting the cutting in a smaller pot. Cover the pot with plastic (allowing for an air hole). Rooting should occur in 6-8 weeks. For a more in depth explanation on propagating azalea bushes, see our page on propagating azaleas. Return to top of page.

5. Generally, plant azaleas in areas of light shade where they will have protection from the hot afternoon sun. Be careful not to plant them, however, in wet areas. Azaleas do like constant moisture, but don’t like to have roots immersed in water. Check the drainage of your planting site. For steps on how to plant your azalea, read our page on azalea planting. Return to top of page.

6. Over fertilizing or over/under watering is your problem. If you have standing water at the roots and poor drainage, the first sign of a problem may be wilted and dying leaf tips. The azalea bush cannot breathe. Solutions? First, take a look at your fertilizing schedule: are you following the label directions accurately? If yes, then look at your watering habits. Check to be sure you haven’t any standing water, and that your plant has moist, but not dry soil. If you cannot improve poor drainage, you may wish to pot your azalea or transplant it. For more information on potting, read our page on azalea window gardens.

7. Powdery Mildew. Spray with fungicide, or wait for hot, dry weather (over 75 degrees fahrenheit) to kill it. If you expect moist, wet weather to continue, go ahead and spray. For more information, read our page on diseases. Return to top of page.

8. This indicates your azalea bush has too much direct sunlight. The leaves are actually burning. Either transplant to a shady location or provide protection from the sun. If you are considering moving it to a container, you might want to read up on azaleas in window gardens at azalea window gardens. Return to top of page.

9. Petal Blight. Spray with fungicide when flowers begin blooming. Replace mulch around plant. Spores over-winter in the soil. Be prepared to spray your azalea bush with fungicide the next year if problem reoccurs. For more information on diseases and problems, read our page on diseases. Return to top of page.

10. Iron Chlorsis. Apply an iron fertilizer like Iron All or spray leaves with a liquid iron solution. For more information on diseases and problems, read our page on diseases. Return to top of page.

11. Root Rot. Usually caused by poor drainage, you’ll want to add organic fertilizer to the soil or transplant. I’ve fought this one and my personal opinion is that if your azalea bushes have a serious case, just replace them (after you’ve fixed any drainage problems). For more information on problems like these, read our page on diseases. Return to top of page.

12. Either wind burn or salt burn. It’s wind burn if you find the problem on new leaves, salt burn if you find it on older leaves. Either provide protection or transplant. Return to top of page.

13. Leaf Rust. Weekly application of a fungicide is recommended. For more information on problems like these, read our page on diseases. Return to top of page.

14. Leaf and flower gall. Pick and destroy infected parts before they turn white and spread the spores that cause this disease. Spray the rest of the plant with a fungicide. For more information on problems like these, read our page on diseases. Return to top of page.

15. Web Blight. Primarily effects evergreen azaelas and can cause complete leaf loss. Spray with a fungicide or use a systemic. For more information on problems like these, read our page on diseases. Return to top of page.

16. Root Weevils. These pests live in the soil as larvae chewing on your azalea roots. When they mature they move on to your azalea’s leaves. Nematodes (small, hungry worms) can be purchased at your garden store and introduced into the soil to eat the larvae. Should you have a severe problem, you can also try spraying your azalea bush with acephate. For more information on pests, read our page on pests. Return to top of page.

17. Azalea Lace Bug. You know you have these if you have black “fly” specks on the backs of your leaves. First try spraying your azalea bush with an insecticidal soap. If this is ineffective, move on to systemics like Bayer Garden Control. For more information on pests, read our page on pests. Return to top of page.

18. Mites. Rub the back of your leaves with a white piece of paper or a white tissue. Have red streaks? It’s mites. Spray with insecticidal soap or a horticultural oil. Heavy infestations? Tray a spray insecticide. For more information on pests, read our page on pests. Return to top of page.

19. You have scales. Scales suck the sap of your plant. Spray with a dormant oil before plant growth starts. Insecticides in spray form only work on the nymphs, but not on the adults. Use a systemic poison if your choose a chemical control. Just scrape off mild infestations. For more information on insects, read our page on pests. Return to top of page.

20. Red Headed Caterpillars. These pests have red faces and white striping, and they rise up on both ends if bothered. Time to corral these little guys — just pick them off by hand. Otherwise try a multi-insect killer or a systemic. For more information on pests, read our page on pests. Return to top of page.

21. Rhododendron Borer. Caterpillar drills into the sapwood where it lives eating your plant all winter. Pruning and destroying infected branches is the first and only organic step for control. If you want to apply a chemical control, use a treatment that includes permethrin and apply in May or June, before eggs hatch. For more information on pests, read our page on pests. Return to top of page.

22. There are several reasons that a plant might not be blooming, but appear healthy otherwise. Here are a few possibilities to consider:

• You pruned too late last year. Buds begin forming for the next year in early summer. If you’ve pruned later, you may have cut off this year’s flowers.

• Your plant didn’t get enough sunlight. Is it somewhat lanky in appearance? Most varieties require at least a few hours of sun per day for bud development.

• Are you watering your plants in the spring and early summer? Insufficient watering when bud formation is underway will cause the plant to go into “survival mode”. The azalea will concentrate on maintaining its leaves and plant structure, but will not form flowers.

• Have you fertilized after bloom has finished? Fertilizers encourage the development of flowers and leaves. Use an azalea fertilizer that has phosphorus as one component. A lack of phosphorus can cause your plant to not set blooms as well.