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cumpaniciu

Pruning long rhododendron branches

cumpaniciu
16 years ago

Hi all,

We moved into a new place last fall and there are three rhododendrons that haven't been properly cared for by the previous owner. They have a lot of long (7 feet) branches that are very thin (probably half an inch diameter, at the base) They had a lot of beautiful flowers this year but because of the flowers' weight all the branches are spread on the ground, making the whole bush look untidy.

I would like to give it smaller, less horizontal shape. The bushes that I like only have two or three thicker branches. Does this mean that if I cut all but three -four branches and prune them to the length I want (about 4 feet) they would eventually get the shape I'm looking for?

Or are there other things that I should look for?

Thank you.

Comments (16)

  • cumpaniciu
    Original Author
    16 years ago

    I have attached a picture of the plant right before it was in full bloom.

    Here is a link that might be useful: {{gwi:389287}}

  • Embothrium
    16 years ago

    'The Honorable Jean Marie de Montague'. Spreading habit characteristic. Do not cut the sides off in an attempt to produce and unnatural truncated appearance! These took years to develop and will lose all elegance by being so mal-pruned. The only area where I see some possible need for alteration is in front of the central bare spot, it looks like some gnawing back has already taken place - resulting in a sort of stubble of flowerless branches. The solution for this would be to stop cutting it back in an attempt to force it into a graceless narrow shape.

  • rhodyman
    16 years ago

    Pruning wouldn't hurt here. This plant is in a very unhealthy state. It has no light or air getting to the inside. It is more like a hedge plant. Many of the branches would be broken off in an ice or snow storm. It looks like it may have been fertilized too much. Rhododendrons seldom need fertilizer and if fertilized at all only fertilize once per year in the spring with half the amount on the label. Holytone is a good rhody fertilizer.

    The trick to pruning rhododendrons is the same as with most other plants. Remove a branch where two branches cross and rub. Remove branches that are growing toward the center of the plant. Remove the ends of branches that are not able to support their own weight. Try to get air and light to the center of the plant. I wouldn't try to change the shape so something unnatural, but try to improve the health of the plant. Here is what a healthy one looks like:
    {{gwi:389293}}

  • cumpaniciu
    Original Author
    16 years ago

    Thank you all! Actually, the one in the first photo was the healthier one.

    Take a look at the second photo. You can see the stake I use to keep the heavy branches off the ground. I assume it should be fine to prune them until they support their own weight.

    Thanks a lot!

    Here is a link that might be useful: {{gwi:389289}}

  • cumpaniciu
    Original Author
    16 years ago

    Didn't know I can post images inline. Trying again.
    {{gwi:389295}}

  • rhodyman
    16 years ago

    That is a good idea. They should be able to support their own weight.

  • botann
    16 years ago

    Why do you feel the branches should not be touching the ground? If you want to turn it into an upright bush or tree you can, but staking is not the way to go. Those lower branches will support the ones above when we get a wet snow or ice storm. If you decide to prune it up, keep that in mind.

  • rhodyman
    16 years ago

    There are several reasons to not have branches that are so heavy they bend the plant over and rest on the ground.

    First, the plant is weak or this would not happen.

    Second, when this happens, the parts of the plant on the ground do not get enough light and air to be healthy.

    Third, it indicates that the plant is growing too fast and becoming tall and spindly rather than strong and healthy.

    Fourth, it is hard to appreciate flowers when they are lying on the ground.

    Fifth, my wife likes flowers that bloom on branches that grow straight up. She uses them for cut flowers. This helps control the height of the plant and provides a great cut flower.

  • morz8 - Washington Coast
    16 years ago

    May I add a sixth? I generally remove or shorten any branches that tend to touch the ground because I don't want to make the trek to the foliage any easier for climbing cutworms and weevils than it needs to be.

    I notice no one has addressed the heavy groundcover under these shrubs - vinca? I have some less aggressive perennials growing under my own ( i.e. our native dicentra), but nothing as heavily rooted as vinca to compete with the rhododendrons/azaleas surface roots.

  • cumpaniciu
    Original Author
    16 years ago

    Yes indeed, the ground cover is vinca minor. I'm not sure whether it's a problem for the rhododendron or not, but it keeps extending into the lawn and I need to trim it.

    Which dicentra species grows best around here?

    Thanks!

  • Embothrium
    16 years ago

    >It looks like it may have been fertilized too much.The healthy color for this cultivar is a deep nearly blackish green, the specimens being discussed are actually pale and clearly in need of fertilization.

    >First, the plant is weak or this would not happenAs I stated this is the normal shape for this cultivar, one that you are perhaps not very familiar with as it is probably not successful in your area - not that forcing myriad different cultivars and species of rhododendrons into a stereotypic concept of proper growth is going to result in them showing their best anyway. But it is very common here, and always has long low branches unless crowded or prevented from assuming its normal shape in some other way.

    Cutting back the sides will result in loss of flowering on those branches - such has already occurred on the small portion on the front that has already been cut back - as well as spoiling the natural spreading habit. Since the plant has a genetic blueprint for growing in this manner it will continuously attempt to restore the "weak" growth for as long as it is interfered with - unless it weakens and declines.

    Here is a link that might be useful: Oregon State University Ornamental Plants II, Rhododendron The Honourable Jean Marie de Montague Plant habit, flowering

  • morz8 - Washington Coast
    16 years ago

    My concern about the vinca with its habit of rooting all along the lengths of the stems was whether it might be competing with your rhododendrons surface network of fine feeder roots for water and nutrients; the leaf color does look a little off in your photos. A mulch of something organic or even bagged compost (not mushroom compost, wrong PH) might make them healthier.

    I think all of the dicentra are happy in Western Washington....I've inherited a large clump of native dicentra formosa that's quite pretty but looks briefly shabby as it slips into late summer dormancy. Dicentra spectablis, and d. spectabilis alba do well, and white d. Margery Fish. Climbing dicentra scandens is thriving but through a caryopteris and along a chain link fence, not climbing a rhododendron.

  • Embothrium
    16 years ago

    Since the rhododendrons do not appear markedly stunted it is probably better to leave the vinca. The root competition it would seem to provide may be offset by the shading of the rhododendron root zone it offers. I certainly wouldn't dig aggressively among the rhododendron roots to get it out, that would be quite likely to be counterproductive - as would anything that would admit hot summer sun beneath the rhododendrons - including limbing them up.

  • rhodyman
    16 years ago

    But thinning it out with a pruning shears and adding mulch would only strengthen the rhododendrons. Mulch should be between 1 and 2 inches deep and not touch the stem of the rhodies.

  • Embothrium
    16 years ago

    Strengthen in what way? The plant has a total energy level that is impacted when part of it is removed. Leaves make food which is stored in stems and used to grow more leaves, stems and roots. And the roots also affect the growth of the top. That is how pruning of roots has a dwarfing effect used to maintain bonsai, cutting back of roots stunts the top. Significantly reducing the crown or destroying a substantial portion of the roots of a mature tree can actually create an imbalance from which it cannot recover, dying after many years of gradual, unavoidable decline.

    Strong appearance of individual shoots produced in response to top pruning creates the false impression of invigoration. But the total annual increase in growth of the top is actually decreased by top pruning.

  • rhodyman
    16 years ago

    Pruning out the vinca will strengthen the rhododendrons by eliminating competition. Vinca will heavily compete with the rhododendrons and will tend to remove moisture and nutrients from the soil they share. Pruning the vinca will not disturb the soil and not disturb the rhododendron roots.

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