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Keyword Search Results for:
rhododendron

17 Found

Question: 139-5201
Can I cut back Rhododendron in the fall? Ralph, Lebanon, CT

Mort's Answer:
If the buds have already formed, it is best to wait until mid summer. Some of the buds will turn out to be leaves but many are next springs flowers. If no buds have formed, than you can prune.

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Question: 140-5201
How far back can we cut rhododendron? Joseph, Southold, NY

Mort's Answer:
All but the Maximum specie should be selectively pruned. You can cut the leggy shoots off at the next junction in July or August after they are finished blooming. R. maximum, which is growing in the woods throughout New England, can be cut by a third. My 6 foot tall Rose bush has had hundreds of blooms in past years.

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Question: 143-5201
When can I remove the dead flowers on the rhododendrons? Jean, Middletown, RI

Mort's Answer:
Whenever they are completely dried. This fall they will start to produce new buds for next spring flowers. You can selectively prune at this time, as well.

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Question: 365-0105
Deer are eating my large red Rhododendron on one side. What can I do to protect them during the winter? Can I cut them back and will they come back? David, Beckley, WV

Mort's Answer:
You can cut them back to the next joint. This will force new growth. You could cover them with burlap for the winter. A large nylon green fence is available for cover or fence. Rotten eggs mixed with garlic can be sprayed on the bushes. This needs to be reapplied often.

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Question: 457-3510
We pruned our rhododendron bush down to about 4 feet. There is just wood showing no leaves. Will it regrow? Ginger

Mort's Answer:
Maximum rhododendron will grow back with severe hacking. Hybrid rhododendron need to be cut back gradually. R.maximum grows wild in the northeast woods. It will come back easily. If you have other rhododendron, they may not be returning.

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Question: 658-4911
Can I cut back my large leaved purple rhododendron ? Jim, Narragansett, RI

Mort's Answer:
You can but you will suffer a loss of flowers. Native R.maxima can be cut severely with loss of flowers in the spring without harm to the plant. Other hybrid rhododendrons will need selective pruning after blooming in July or August instead of the hacking of R.maxima.

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Question: 701-812
My rhododendron leaves and some holly are turning yellow since the onset of winter. I replaced a few larger rhodys with four this year. This past summer I had fertilized them twice. They looked good in the summer. I did not see any sign of insects. What cold be the problem? Dern, Lewisberg, WV

Mort's Answer:
Your winter has been very mild this year like so much of the US. Unfortunately, pathogens that would ordinarily be killed by frosts, have survived in many areas. Twig blight and wilt are common maladies of rhododendron and holly. Snap a branch off and see if there are any black streaks inside the branch. Twig blight is treatable with plenty of well rotted mulch and well drained soil. If you see brown streaks inside the bark, you plant has wilt. This causal fungus can be treated with Bordeaux Mix spray. The soil should be covered with the powder. Remove all infected branches. If you are not successful with irradiation of the wilt within a year, you will have to remove all infected plants to keep the disease from spreading.

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Question: 714-1112
My rhododendron that is about 6x6 ft.is turning brown this winter. What could it be? Doris, Pena, IL

Mort's Answer:
You should dig out some soil near the root. If the soil contains grubs, you can remedy this with a grubicide. Unfortunately, pathogens that would ordinarily be killed by frosts have survived in many areas. Twig blight and wilt are common maladies of rhododendron and holly. Snap a branch off and see if there are any black streaks inside the branch. Twig blight is treatable with plenty of well rotted mulch and well drained soil. If you see brown streaks inside the bark, your plant has wilt. This causal fungus can be treated with Bordeaux Mix spray. The soil should be covered with the powder. Remove all infected branches with wilt. You will have to remove all infected plants to keep the disease from spreading at the end of year.

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Question: 918-1513
Should I prune back my rhododendron now or later? Mary, Norwich, CT

Mort's Answer:
If you prune now, you will do no harm except that you will remove a lot of flower buds. A good rule of thumb is to wait until the flowering plants have finished blooming. It will probably be in July for your rhodys. Do not use hedge shears. Hand prune each stem down to the next joint. This elective pruning method works best unless the plant is heavily damaged. When plants are almost ruined, a crew cut works anytime after forsythias are in bloom.

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Question: 919-1513
Deer have completely stripped my rhododendron. We live in a rural area. What can I do to revive them? Mary Ann, Lewisburg, WV

Mort's Answer:
In the long run, you should consider a mechanical barrier. Green nylon chicken wire comes in 10 foot high rolls. Cordon off an area that should include your driveway. You can make an inexpensive gate with the nylon You can apply rotten eggs and oil or a commercial concoction to your plants. These are often washed off by the rain. I would cut the rhodys in half right now. They can be fertilized with a granular 5-10-10 to help them survive the apparent devastation. The deer population has been increasing in many areas. Most folks like having them around but not in their bushes.

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Question: 1122-1914
My rhododendron is not doing well. The leaves are curling and drying up. They have black spots on them. I have them in wood mulch. I also have some phlox that is mixed with weeds. Is there a spray that I can use? Mark, Manchester, NH

Mort's Answer:
Your best bet is to remove the phlox when they are not in bloom. Separate the weeds from the plants and then replant them. Do not fertilize them until they have restarted growth. You will have to cut out all spoiled leaves on the rhododendron. When you cut the branches, check the inside of the twigs. If there are streaks of black or brown, keep cutting branches until you reach all white. Wilt on lilacs and rhododendron can be caused by fungi that winter over on evergreens and in mulch. Remove the mulch and cultivate with a dust mulch, if the plants are not infected down to the roots. Fully infected plants have to be removed.

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Question: 1173-4014
I need to cut back my large leaved purple rhododendron. Can I do it now and how far? Amy, North Kingstown, RI

Mort's Answer:
Rhododendron maxima is a native to Rhode Island and grows very big. Pruning now runs the risk of cutting off buds that will bloom in the spring. Sometimes we see some premature flowers in the fall. I have seen Maximum rhodys cut down to a foot from the ground. I would not recommend such abuse. If you see buds now, you can cut branches around its stems by cutting back to the next branch. Do not shave them like a hedge. You will get a lot of brown leaves that are not too pretty. I would use loppers and a hand pruner.

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Question: 1195-4514
I have a large purple flowered rhododendron along the driveway. It is too big and I would like to cut it back. When can I do this? I also have a paper bark maple that is five feet tall. Should I cut it now? Roger, Groton, CT

Mort's Answer:
Maximum rhododendron is native to southeast New England. I have seen them 15-20 feet tall. Unfortunately, you should wait until August unless you do not mind losing flower buds that are setting now. Do not cut them like you would a hedge. Select whole branches to thin the top and sides. Remove whole branches down to next branch inside. I would let the paper bark maple alone. When it matures in five years, you could thin out the interior. This will allow wind to pass through the tree. Maples should be pruned in mid summer or winter.

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Question: 1239-1315
Deer have eaten my large leaved Rhododendron. How far can I cut it back? Mary, Uncasville, CT

Mort's Answer:
Because of the severity of this winter and the scarcity of food for animals, there have been a lot of damaged plants. You can cut the Maximum Rhododendron back to a foot from the ground. This large leafed purple flowering rhododendron is native to Connecticut and Rhode Island. It has endured many a pruning from deer over the centuries. If your plant was a newer hybrid, I would recommend taking it back to green leaves. This can be done as early as you want. You will probably not have flowers this year.

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Question: 1251-1815
We have two purple, one white and a pink rhododendron that were chewed by deer this winter. One was severed to the ground. They were about five feet tall. How can I prune them? Tom, Preston, CT

Mort's Answer:
Sterilize your loppers with bleach before using. You need to cut each damaged branch to the next clean stem. Cut as flush as possible and use tree seal or tree wax to cover the clean cuts.You need to cut back the totally flattened one to the main stem. Look to save a branch with some leaves on the runt. This will allow the plant to get vitality from the sun. It will require some appeal to St. Francis or some other patron of the Gods on behalf of the lowest one.

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Question: 1381-3916
Can I cut back my 10 foot Maximum Rhododendron now? Julie, Norwich, CT

Mort's Answer:
The short answer is yes. You will take off a lot of the flower buds that are forming as I write. If this does not concern you, then you can cut the shrub down to three feet or less. This native rhody grows quickly and easily to reach its ultimate height of 10 feet. Use lopers for a more clean cut back. Mid summer after it has finished blooming is the best time, if you want flowers for the following late spring.

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Question: 338-5201
When is the best time to prune Rhododendrons? Frank, Oakdale, CT

Mort's Answer:
The best time to prune most flowering plants is after the blooming has dried. In zone 6, most rhododendrons have finished their bloom in August. You can selectively take out the taller stems down to the next joint. Do not hack off the tops or sides. Although the native rhododendron, Maximum, can survive flat top scalping, it takes a lot of energy to recover from such a massacre. Your can do this over a two or three year period until you have cut down the plant to a manageable size.

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