Confused about pruning azaleas and rhodies

[Patty Winter]

I have a handout from the American Rhododendron Society that says the best time to prune rhodies and azaleas is in the spring, just after flowering. Makes perfect sense to me, but the plants aren't cooperating. :-)

By the time the current year's flowers are fading, the plants are already forming buds (flower? leaves?) for next year. So if I prune then, I'll end up removing new growth, and then won't I have a barren plant for a year? But if I don't prune, then I keep getting growth farther and farther out the branches, leaving the centers of the plants increasingly empty. Any suggestions?

Thanks! Patty

[Bill]

I never prune them. Just dead head when I got the energy. But I do prune in a way. I cut back to healthy wood killing borers in the process with a focused intent. I'd guess your mention of empty centers may be due to plants younger plants less than 10 years.

Best!

Bill

[Phisherman]

You only have two choices: Prune and lose some next blooms, or Don't prune and allow the plant to get larger.

Personally, it would depend on the location and I'd prefer to leave it alone (not prune) and mulch the azalea. Azaleas and rhododendrons often look just fine in their natural unpruned state.

[Patty Winter]

Do they fill in the inside part when they get older? Mine are probably 5-6 years old.

Patty

[Patty Winter]

That's what I was thinking: maybe prune and lose one year of blooms, but have a healthier plant the following year.

Most of the azaleas are fine and bushy. One is a bit sparse in the middle, but full enough on the outside to cover it up. The rhodies aren't so full, so the bareness of the inside parts shows quite evidently. Wouldn't that be a case where pruning might help?

Patty

[Tom J]

Depends on where you live, it may be too late this year. You should do the pruning within days of the blooms dying. In my case, I don't "prune" as such, but grab the limbs where I want to shorten them and give them a sharp snap and just break them off. I have bushes full of blooms every year doing it this way.

Tom J

[Stephen Henning]

Hi Patty,

That is very strange. Usually, in early June, rhododendrons and azaleas have just finished blooming and are opening up their foliage buds and forming new growth of stems and leaves. The new leaves may look like they are coming out of buds that are forming on the new stems. You might be mistaking them for next years buds. Then, in mid summer, new buds form on the ends of these new shoots and at the base of the new leaves. Some of these buds are foliage buds and others are flower buds. You usually have until early to mid summer to prune. Obviously the closer after blooming is the safest.

The reasons for pruning healthy plants are two fold: 1) to contain or reduce the size of the plant(s) and 2) to stimulate new growth. For the latter to take place the plant(s) must have some sun and since yours seem to bloom nicely, I would guess they get part sun.

Another good way to fill out the center of the plant(s) is to break off the new foliage buds on the outer-most branches in the spring after the flower buds swell up and begin to bloom. When the flower buds begin to look like green golf balls, the foliage buds will be much smaller and easy to spot. You can remove them by just twisting them sideways, sort of like deadheading.

Deadheading is the removal of the spent flowers to prevent the formation of seed pods and to remove any diseased material. In areas with petal blight, which is a fungus that attacks flowers and makes them wilt prematurely, the removal of spent flowers is very important. If flowering is a problem, deadheading can improve the bud set for the next year.

[Patty Winter]

Okay, your information matches what was on the rhodie society handout, but I'm still confused. As you say, there are new leaves coming out right now. But those aren't related to next year's foliage and flower buds? I'm safe cutting below them, if they're on the end of a stem and I want to trim back further?

Yes, they get some morning and afternoon sun, but not midday. One of them didn't do much flowering this year, but I'm attributing that to my not having pruned it properly in the past. The other one right next to it bloomed fine this year. It's a younger plant, so hasn't been "mistreated" for as long!

Oh, interesting. I hadn't heard of that technique before. Out of curiosity, will that delay foliage growth for a year, or will the plant immediately begin making foliage buds closer to the center of the plant?

I've been doing that every year, breaking off the flower stems at the place where they naturally break, kinda like asparagus. ;-)

Thank you very much for this information, Stephen. And also to Tom for his suggestions.

Patty

[David E. Ross]

In general, trees and woody shrubs that bloom only in the spring should be pruned right after blooming. Of course, don't prune if fruit is expected. And not every plant needs to be pruned, especially not annually.

I prune my azaleas to renew them. This means pruning once every 3-4 years. If I leave a bare branch, several new shoots will form on that branch. If I leave some foliage at the end of a branch, I remove the tip in order to promot more branching.

Yesterday, I pruned my 'George Taber' azaleas. They form an irregular hedge in front of my camellias. The azaleas had grown so tall and dense that they hid the camellias. None of my other azaleas -- 'Alaska', 'Formosa', 'Inga', or 'Pride of Dorking' -- will be pruned this year.

[Patty Winter]

That makes me feel better, David. ;-) Perhaps I haven't been neglecting the poor things as much as I thought. I'll prune this year and see what happens. Even if things go wonky and I don't get many flowers next year, 2010 should be great! :-)

Patty

[Stephen Henning]

That is right, they aren't related to next years buds.

Yes, you are safe in cutting below them.

Now, it encourages other buds to grow and fill out the plant. It only stops the growth of the bud you remove.

It should be a spongy areas at the very base of the flower. For pictures go to

click on "Sanitation & Deadheading"