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pollyfan

rescuing older, non-blooming azaleas

pollyfan
16 years ago

When we moved into our (very overgrown) house last summer, we started by having 16 trees taken out. We now have light and space . . . and under the trees we found several large (6 x 6 foot at least, and bushy) azaleas. This spring most of them have put out a few flowers, mainly on the top, but mostly just a lot of leaves.

We'd really like to move them out of the center of the garden--we plan to have a lawn where they are--but would like to save as many of them as we can, and to improve their flowering if possible.

I've heard of something called "rescue pruning"--cutting down to about 12" after they've bloomed--but that sounds a bit drastic to me. How much can we safely prune, and can we also move them or should we prune this year and move next?

Thanks for any advice!

Comments (22)

  • bullthistle
    16 years ago

    Actually I've never heard of rescue pruning, but then I am from the old school, however if pruning them back you will still have to dig them up and if they are really old there is no way you could safely transplant them without a Vermeer tree digger because the roots would be enormous so you may be cutting back the top but what about the roots?

    Here is a link that might be useful: Propagating Perennials

  • morz8 - Washington Coast
    16 years ago

    pollyfan, the number one reason for failure to bloom is too much shade. You may have already solved that problem with your tree removal although since the buds are set in summer for the following seasons bloom, it would be a year before you know the results.

    I think you're referring to renovating pruning, or renewal pruning. The safest way to heavily prune azaleas is to remove 1/3 of the branches per year so that at the end of three years, the plant has been renewed.

    Admittedly few of us have that kind of patience and while there is some risk, healthy well established azaleas will normally respond well to cutting back to within a few inches of the ground all at once. There are dormant buds under the bark all along the stems and those should begin to sprout within just a few weeks.

    You don't indicate what garden zone or area you are in - that limits how many steps at once you may want to take with your azaleas. You could prune this Spring, move in Fall in milder climates or you may want to wait until the following Spring if in a harsher winter area.

    A dense fibrous root system and habit of shallow rooting makes azaleas among the easiest shrubs to move. Even large old specimens may be moved successfully if reasonable care is taken. You can assume the plants root systems extends out as far as its branches reach, but you can take a smaller root ball safely - Aim for a rootball equal in diameter to two-thirds the plants height (height before being pruned if you prune them) if possible. Drag on a sheet of cardboard or tarp to the new site, easiest on backs and on the rootball, even if you could lift it, the weight would damage the fine feeder roots.

    While not usually necessary in my own mild climate, for added insurance you could root prune the plants a year in advance of their move.

  • pollyfan
    Original Author
    16 years ago

    Thank you for the advice! I'm in zone 7, apparently!

  • joel_bc
    16 years ago

    I understand why people prune branches - sometimes drastically - in order to remove dead branches and/or to prune away the ends of live branches so as to eliminate apical dominance. In a vigorous plant, it should help to produce more secondary branching and foliage.

    There is a vigorous discussion going on in the House Plants forum concerning the value of root pruning for indoor plants, which practice is said to boost the vitality of an indoor plant and markedly extend the plant's life. So it's got me wondering if azaleas and rhododendron's might benefit from a root pruning every few years. ?? This is assuming the plant is not near death's door, and that the gardener is willing to dig down into the soil to carry out this pruning, and that the gardener did not OVER-prune.

    Experience? Opinions?

    Joel

  • rhizo_1 (North AL) zone 7
    15 years ago

    Azaleas are one of those plants that respond very well to rejuvenation ( renewal) pruning. Take them down to 6 inch stumps and watch them grow! Shocking at first, but you'll be very satisfied with the results.

    Joel, growing a plant within the confines of a container is completely different than allowing it to grow naturally into the soil. There is no reason to root prune azaleas in the ground. They are able to develop extensive branched root systems naturally. It's only when a root system runs out of space to grow that root pruning becomes beneficial.

    Root hairs are the only place on the root system that absorbs water and dissolved nutrients. Root hairs are formed only on the tips of the newest roots....thus, root pruning triggers a flush of new root growth into the space provided by the 'surgery'.

  • joel_bc
    15 years ago

    rhizo, you wrote: "growing a plant within the confines of a container is completely different than allowing it to grow naturally into the soil. There is no reason to root prune azaleas in the ground. They are able to develop extensive branched root systems naturally. It's only when a root system runs out of space to grow that root pruning becomes beneficial.

    "Root hairs are the only place on the root system that absorbs water and dissolved nutrients. Root hairs are formed only on the tips of the newest roots....thus, root pruning triggers a flush of new root growth into the space provided by the 'surgery'."

    But then I do wonder whether sometimes the woody root system, which is not absorbing nutrients, may become too extensive. The roots of a plant (such as an azalea in a garden" may have sprawled its actual feeder roots & fine root hairs out into an area where many neighbouring plants have theirs - could there not then be a competition for water & nutrients?

    J.

  • rhizo_1 (North AL) zone 7
    15 years ago

    Absolutely! But the whole underground universe is a mass of root systems. Most times they (the plants) figure out how to work it out. :-) By limiting the root system of an in situ plant, you prevent it from one of the most essential tasks of all....that of energy storage. The root system is the most important organ of all for storage.

    Chronic root pruning will not only limit the reserves of the storage organ, but also forces your plant to USE energy to make more roots. That's fine for container plants, but not for our outdoor plants. They need all of those stored energy resources.

  • pollyfan
    Original Author
    15 years ago

    Thanks for all the advice! :-)

    rhizo, when would you advise a drastic pruning? After blooming, or fall, or when? How long will it take for them to grow back into something that resembles a flowering shrub rather than a 6-inch spike?? And would it be possible to move them at the same time, or would it be better to prune and move at different times?

    Thanks!

  • carissa_mom
    15 years ago

    Hello;
    I live in Virginia and I kill plants. I don't want to, but it always happens! Because of this, my hubby will not allow me to buy plants.

    Today, when I got home, I noticed my neighbor digging up his huge, ancient azaleas with a vengence. He said he was throwing them away, so I asked him if I could have them. They are now in my basement in a utility sink.

    I have the root balls watered and wrapped in plastic. Can I drastically cut these back, pot them, and keep them under a UV light in my basement until late spring, then plant them outside?

    Thanks so much!

    Carissa

  • pollyfan
    Original Author
    15 years ago

    Hi Carissa.

    Well, here's what happened with our azaleas--might give you something to think about!!

    We decided last May we wanted a lawn. So I hacked and chopped till all that was left of the azaleas above ground was about 12" bare stems. My son and husband then hacked the roots out of the ground and shook off all the dirt.

    We had initially intended replanting them elsewhere in the garden, but what with one thing and another, we didn't get round to it, and they were just bundled together in an overgrown area of the garden.

    Surprise! When I happened to look at them later in the season, almost all of them had put out strong new growth . . . and this was with the roots just bare and sitting on top of the ground! So next spring I'm going to get round to rewarding them by planting them somewhere!!

    I guess what this shows is that it's actually pretty hard to kill azaleas!! I'd say definitely give it a shot--if they survive the winter I'd think they would make it. Maybe someone more knowleageable than I am would be able to advise, but I don't know whether potting and UV lighting them would be best--maybe you should just dump them out in the garden somewhere?? Certainly pruning drastically doesn't seem to do any harm, and definitely make them easier to handle from a size angle.

    Good luck!!

  • carissa_mom
    15 years ago

    Wow. Maybe I'll be able to add Azaleas to my list of unkillable plants? I already have vincas, gladiolas, and climbing rose bushes that have survived my morbid sense of TLC!

  • rhodyman
    15 years ago

    Hi Carissa,

    Old healthy plants will grow from energy in the roots for a short while, but will eventually need the small fine feeder roots to provide nutrients and water.

    First, don't thaw them out now. Leave them in an unheated garage or some place like that where they will stay dormant. Keep the roots moist but not wet. Make sure any container has drain holes in the bottom. The main killer is root rot from wet roots. When the ground thaws out, plant them in an area with partial shade, acidic soil, and excellent drainage.

    In the spring cut the tops way back. Cut off the tops so that you leave about 1/3 of the leaves. If they were growing in a sunny location, you should be able to cut them back even further.

    The critical time is the spring when they are getting established. They must be kept moist but not wet. They will need some partial shade. Afternoon shade is ideal.

    Here is a link that might be useful: How to grow azaleas.

  • carissa_mom
    15 years ago

    So I can't whack the tops until it is spring and they are in the ground, correct? I'm just concerned about the space they'll take up storing them.

    They are in my basement laundry room which is pretty cold. There's no heat in there. Is a basement cold enough?

    Gotcha on the root rot. I'll cut off the bottoms of the bags and let them drain. (See, I was already trying to do them in!)

  • rhodyman
    15 years ago

    Hi Carissa,

    There is a possibility that pruning them may stimulate them to break dormancy. It does in some plants, I am not sure about your azaleas. You don't want them to break dormancy (open buds) until in April or May.

    It might be better to leave them outside on the north side of a building if you can where the sun will never hit them. They were outside so are perfectly hardy and were hardened off. The roots should be covered with something such as mulch (leaves, pine needles, bark nuggets)that will protect them from changes in temperature and wind burn.

    If they do break dormancy, you will need to bring them inside and nurse them along until April or May.

  • morz8 - Washington Coast
    15 years ago

    My own ground doesn't freeze to any depth at all, and - I've never been to Virginia....

    But the Zone maps show a good deal of that state to be Z7, and Carissa did say her neighbor was digging within the last few days. Any thoughts as to her planting (no deeper than originally growing of course) now and watering in well or would there be too much winter left in her climate?

  • carissa_mom
    15 years ago

    Hmmm.. yes, I'd like a gander on that. I'm planning on planting them on the SW side of my house, though.


    It would be possible to put them on the North side of my house and cover the roots if that would be best for them.

  • carissa_mom
    15 years ago

    I'm zone 7a/6b- I'm right on the line. I'm at the foothills of the Blue Ridge Mountains. If that helps any.
    Carissa

  • rhodyman
    15 years ago

    Carissa,

    If you can work the soil, then plant them on the SW side of the house. I would put up a burlap barrier on the S side of the azaleas to shade them at least until they show some growth and and look healthy.

    If you plant them, then prune the tops back then. It will help them get established. When the weather warms up they are going to struggle until they get some roots established.

    Make sure the root ball doesn't dry out. If it does, then when you water the water will just run off the root ball. If the root ball isn't moist, soak it before planting.

    Again, acid soil, drainage and mulching are important. Do not plant any deeper than there were originally. Raising them a little is best. Then mulch them well.

    Here is a link that might be useful: How to grow azaleas.

  • carissa_mom
    15 years ago

    Ahhh... very do-able. Thank you so much for all of your help! We'll see how it goes! I hope they live. I'll be sooo happy!

  • carissa_mom
    15 years ago

    One more odd question. Every time I handle them, I break out in hives on my hands and wrists. Is there something on them- (The neighbors have cats which I'm allergic to)or is it common for one to be allergic to azaleas?

  • morz8 - Washington Coast
    15 years ago

    Carissa, no, azaleas are not commonly thought to cause allergies - allergies can be highly individualized but this is not one of the plants that often provokes a reaction....and that's not to say it absolutely could not where you are concerned.

    I suppose the cats could have rubbed through them, but your best bet might be long sleeves and gloves, change out of those immediately when finished with the plants and wash with soapy water, rinse, before itching begins if possible.

    I'm not especially sensitive but have had a similar reaction to something (I don't know what plant) when picking wild berries.

  • schifferle
    9 years ago

    Carissa, azaleas can indeed cause skin reactions in some people. Every part of the plant is poisonous, so it's not a stretch to have hives or get a rash from touching them. My daughter has sensitive skin and broke out in an itchy rash when I asked her to prune them for me. That was the first & last time she was willing to handle them. Wearing gloves, etc. is good advice.

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