Hydrangea and Rhodedendron in desperate need, please help!

[tmneese]

I have both Rhododendron and Hydrangea that are in terrible need of some pruning. They are growing over the pathway to the front door! I'm not sure their age. But 5 feet tall about and 4 feet wide. Both had beautiful flowering buds May, June and July. Is it to late to prune? This wouldn't be "light" pruning either. I can barely make it to the front door!

And, If I cut back more on the bottom and light on the "canopy" my growth next year will be more dense? Dense is great I just need it off the walk way.

Also, there are two separate Rhododendrons that are weak, thin and brittle. They had no growth this year at all. They do have some green leaves and there is some life but not much. If I try to do a "renewal prune", is there such thing as to much pruning? I'm worried whether I prune these guys or not they just might not make it through winter. Any tips, suggestions or opinions are greatly appreciated! Thanks everyone. Have a great day!

~T

[Kisal]

Welcome to the Helpful Gardener forum! I'm sorry that I can't offer advice about the hydrangea, as I have little experience with them. I just bought my first one a few weeks ago.

However, I've been growing rhodies for about 30 years, so I can help there a bit. It's late to prune a rhodie now, although it won't do any harm to the plant. You'll be cutting off the buds of next year's flowers, but if that's what it takes to get to your door, I wouldn't hesitate to do it. (Better than spending the rainy season outdoors, after all! )

First, you want to remove any dead branches. Second, remove any branches that rub against other branches. Finally, prune the shrub to the size and shape you want it to be. Do not remove more than 1/3 of the living tissue of the plant, though.

Rhodies take well to pruning, and I would say they even like it. In the wild, deer browse on the branches, which is nature's way of pruning a plant.

This link is to a video about how to prune a rhododendron:

https://www.5min.com/Video/How-to-Prune-Rhododendron-30729553

If you really think the other rhodies are going to die, you can do a fairly hard pruning. I've never cut one back further than down to 3 feet, though. (My plants average about 8 feet tall, which would mean I cut away more than half of the plant.) You definitely don't want to cut back so hard that you remove all of the leaves. I would never recommend hard pruning a plant like that, unless you really wouldn't miss it if it died, because it very well might. Hard pruning sometimes works, but there's a high risk factor. I think you would be much better off just to do a proper, standard pruning, and wait to see what next year brings. A rhodie with weak growth can improve 1,00 per cent after a decent pruning. However, if a plant is in very bad shape, it might take 2 or 3 years of good care to bring it back.

Be sure to fertilize in early spring with a proper rhododendron/azalea food, to help keep the soil acidic. If I'm renewing a plant, I sometimes feed it a second time, immediately after it's finished flowering. Don't feed after the end of July, though, or you risk encouraging new growth that won't have a chance to harden off before winter sets in.

[luis_pr]

Good morning, tmneese. I hope everyone is doing well, as I happened to notice the time of these posts and gee, shouldn’t we all be sleeping? Hee hee hee. My excuse is a dog with a sick tummy. Woke me up when I heard this –err- sound (please, no details!) and had to let her go out and eat some grass, weeds or whatever it is they like to do when this happens. But I digress. Let’s talk about your other sick patients as I wait for mine to return….

Pruning recommendations for hydrangeas are somewhat similar to the good recommendations already given by Kisal. You can prune stems that cross, those that are growing too much and –of course- those have dried out. Security, plant variety and aesthethics should dictate when and what to prune.

If there is hazard caused by all this hydrangea growth, prune as soon as possible and do not be concerned about missing blooms in Spring 2010. It is a must do.

Contrary to rhodies though, hydrangeas may bloom on old or new wood. This may let you prune now and still get flowers after all. Do you know what type of hydrangeas you have and the name of the variety? The type can be the well-known macrophyllas (mopheads and lacecaps) or oakleafs, paniculatas, arborescens, asperas, serratas, villosas, etc.

Macrophyllas are the ones that can bloom on either new or old wood but that depends on the variety. The Endless Summer Series, for example, is a macrophylla variety that can be hard pruned now and will still produce blooms next year. Other macrophylla varieties, like Nikko Blue, start developing flower buds now (they are not visible) and pruning [i]now[/i] would result in no blooms next year. In the future, you can prune according to the type of hydrangea that you have.

Mopheads and oakleafs can be pruned after they bloom but before they develop flower buds so make a habit of pruning these in June. Every 5-7+ years, you may notice lackluster bloom production some times. You can rejuvenate the shrub by pruning 1/3 of the stems each year until you have pruned them all. Prune as close to the base or crown as you can. You can start with the 1/3 oldest and longest stems. All other forms of heavy pruning can be done when the macrophyllas are dormant, to reduce shock to the system.

Paniculatas and arborescens always bloom on new wood so they can be pruned at any time except when they are about to bloom. Arborescens start to bloom in the Spring and Paniculatas start later, in June-July.

Plant material resulting from all this pruning can be composted provided you do not have fungal problems with the plants. If you do, dispose of them in the trash (in plastic bags).

Regarding your rhodies, you may want to forget about doing any pruning if their health is so-so. Instead try to determine what is causing the problem and address that. If you have to prune and if you can wait then minimize shock to the plant by pruning in winter. To me, it sounds as if there may be a watering issue. Try to consistently keep the soil moist, not wet, at all times and provide 3-4" of acidic mulch so you do not have to water often. As a safety check, look for evidence of bark split or borers. These could also cause browning of sections of the plants. Plants like these that are in stress should not be fertilized.

Rhodies are best pruned after they finish blooming. Pinch at that time to make the plants denser.

With large-leaved rhodies, prune just above growth joints that are formed at the beginning of each growth season. Dormant growth buds are located below that spot.

For small leaved rhodies, prune anywhere on the stem because these shrubs have adventitious dormant growth buds all over the stems.

Have a good evening guys!