Leaves Turning Brown And Falling Off Admiral Semmes Rhododendron In Summer

Filed Under: Rhododendrons · Keywords: Leaves, brown, Falling, Off, Rhododendron, Admiral Semmes, Native Azalea · 2430 Views
Planted 14 rhododendrons this spring. 3 are the admiral semmes. Have carefully watered and fertilized thus far. Seemed fine until last couple of weeks. Leaves are turning brown and falling off. No noticeable pest. All neighboring rhododendrons/different variety, seem fine.

Any help would be appreciated.

THank you

Rate It 2

Comment about this question »

1 Answer

Answer #1 · Maple Tree's Answer · Hi Christina-Leaves that turn brown, die, and drop off in the summer can be caused by several things. The problem can be insects, disease, or stress from too much water, too little water, or too much fertilizer. If you can upload a picture of the plants and an upclose picture of the browning leaves it would help in identifying the problem. Above this and to the right of you name below your question you will see where you can upload any pictures you have saved on your computer. Are these azaleas growing in full direct sunlight or are they shaded at times of the day? Are the leaf tips only browning or the entire leaf before dropping? Is there any spotting or other discoloration of the leaves other than just turing brown? How often are they watered? Have they been fertilized and if so how much and with what type of fertilizer? Too much fertilization can burn the azalea especially newer plants. Too little water can also brown leaves causing them to drop as a way for the plant to protect itself and survive with less foliage during hot summer conditions. Sometimes watering the soil surface everyday may not be enough water. It is important to water slow and deep making sure the entire root ball is being moistened to its depth. This is important during the summer at least once a week while the plant is establishing a good root system. Azaleas have a shallow root system and should be mulched helping to keep moisture in the soil especially when planted in hot afternoon direct sunlight. Dig down 6 to 8 inches in spots around the plants. Make sure the soil feels cool and moist but not wet or dry. If you can answer these questions, let me know what you find when checking for soil moisture, along with a picture it should help to find the problem of the browning and dropping of leaves. Have you had unusually hot temperatures the last few weeks as some locations have? I'm thinking that this problem occurring in the last few weeks may be caused by too little water, too much direct hot sunlight or both.


Additional comments about this answer:

Christina Southern

Christina Southern · Gardenality Seed · Zone 8A · 10° to 15° F
Hi John,
Wow! Thank you for the quick response. My Aunt, who has been an avid gardner for 50 years had her landscape crew plant these bushes in April. They were watered with a sprinkler system (2 hours each time) fertilized weekly per her instruction. I went to feeding once monthly once the summer temps increased. Learned about watering from watching my parents plant azaleas when I was a child. They have been watered at least once weekly unless there was a substantial rainfall. In July, watered additional times if plants were drooping. Toward the end of July, I was out of town for a week and it was brutally hot here. My sister, who lives with me hurt her knee and the plants did not get watered. It looks as if the browning starts at the tip and slowly turns the whole leaf brown. They receive full sun until about 4pm. I will get a picture asap. I work for a veterinarian, so my schedule is usually 8 to 8. Long days. It is a bit odd that all of the other varieties are fine.

7 years ago ·
1 Green Thumbs Up
· Unthumb

Maple Tree

Maple Tree · Gardenality Genius · Zone 10A · 30° to 35° F
It does sound as though not enough water may have been the problem. Its hard to tell why some plants do better than others at times. The species and cultivar of azaleas can determine their resistance to temperature and moisture conditions. I have found many growers using very light well draining soil mixes for the azaleas. Until the roots penetrate the surrounding soil the root balls can still drain well and dry out quickly. Most nursery grown plants have been fertilized and may not need much fertilization their first season in the ground. Burning of the leaf tips could also be too much quick release fertilizer. I always like using an organic fertilizer or a slow release granular fertilizer as these release nutrients over a period of time with little chance of burning. Liquid fertilizers with a high nitrogen content can easily burn plants even more so during hot temperatures as the plants are more quickly taking up the nutrients and water they need. The Admiral Semmes Azalea is a cross between a large flowered Exbury Azalea and a native Florida azalea. In their natural environment these azaleas can adapt to more full sun during the day but do much better in patial shade especially in the hot direct afternoon sun. If these azaleas were started and grown in a more shaded environment it may also take some time to acclimate themselves to more direct sunlight. Hopefully your pictures will indicate what the problem is.

7 years ago ·
0 Green Thumbs Up

Gardenality.com · Gardenality Genius · Zone 8A · 10° to 15° F
Leaves browing from the tips and working inward is usually an indicator of too much water in the soil. When soil is too dry usually the leaves will wilt first and then suddenly turn brown and drop. Shedding of leaves is sometimes a natural response to survive a drought and doesn't always cause death of the plant. If the underbark is stilll green the plants may leaf back out. With no leaves on the plant it won't drink as much water. So, soil moisture should stay only damp to moist, not constantly soggy or wet, which could cause root rot. Regarding feeding native azaleas, I always use a mild organic fertilizer...just one feeding in spring is usually enough, though a late summer or early fall application can be beneficial.

7 years ago ·
1 Green Thumbs Up
· Unthumb

Comment about this answer »
Rate It 1

Post An Answer To This Question:

Can't find your answer? Click here to ask your question.

Read Tips On How To Give A Great Answer

Click here to learn how to give a great answer »


View All My Gardenaltiy Updates »