Return to the Hydrangea Forum | Post a Follow-Up

 o
Scale (cottony maple?) attacking preziosas. How hard can I prune?

Posted by jillyluis none (My Page) on
Mon, Jun 20, 11 at 9:05

I have three beautiful preziosa hydragneas that I love. I believe they were planted eight years ago, and they are quite large, about 5 x 4 feet. They are being attacked by scale: I'm pretty sure it is cottony maple scale. My husband sprayed neem oil a couple of weeks ago, and it seems like only about 10% are left....but 10% of thousands of scale is still quite a bit. The hydrangeas had a tough time recently: I don't know if it was the drought last summer (I tried handwatering, but doubt I kept up) or the tough winter we had, but I have a lot of branches that aren't dead but don't have any foliage either. Also, I cut off some of the branches heavily infested by scale, so now the bushes look terrible.

My essential question, is how hard can I prune the bushes without killing them altogether? They are just too big, and I don't see how I can get all the scale with all the leaf cover they have right now. I can live without flowers next year, but I really really really hate scale. I've thought about ripping these out and replacing them, but that seems a bit aggressive at this point.

Any other suggestions would be helpful! There is a lot of conflicting information on the web about when to treat etc. We don't in general use pesticides (neem oil or horticultural soap is about as aggressive as I'd like to get)

Thank you!


Follow-Up Postings:

 o
RE: Scale (cottony maple?) attacking preziosas. How hard can I pr

I'm zone 6A if that helps.


 o
RE: Scale (cottony maple?) attacking preziosas. How hard can I pr

I'd need to see photos to confirm the problem before I made any suggestions.

Scale is a difficult garden pest to control and if the infestation is severe enough, the recommendation is to remove and destroy the plant. Some systemics may be effective but before going further, I'd want to see how bad the situation was :-)


 o
RE: Scale (cottony maple?) attacking preziosas. How hard can I pr

Here are some not so great pictures...I took them with my phone, so the closeups are out of focus. Is there anything in particular that would be helpful to see? We have a digital camera....somewhere :)
Thanks a bunch!

Image and video hosting by TinyPic

Image and video hosting by TinyPic

Image and video hosting by TinyPic

Image and video hosting by TinyPic

Image and video hosting by TinyPic


 o
RE: Scale (cottony maple?) attacking preziosas. How hard can I pr

It's a cottony maple scale, indeed, and for the last 2-3 years we have a severe infestation here in New England.
Due to their life cycle they are very hard to get rid of completely.
As far as I know (from my own experience) only Safari (Dinotefuran) if applied twice a year (at the right time) AND for two years on a row could give you complete freedom from the beast.

Re: as far as hydrangeas concerns. If you cut them to the ground now then by the next year you'll have a nice healthy rejuvenated shrubs.

P.S. Every leaf and branch from infected plants must be burned, not composted.


 o Post a Follow-Up

Please Note: Only registered members are able to post messages to this forum.

    If you are a member, please log in.

    If you aren't yet a member, join now!


Return to the Hydrangea Forum

Information about Posting

  • You must be logged in to post a message. Once you are logged in, a posting window will appear at the bottom of the messages. If you are not a member, please register for an account.
  • Posting is a two-step process. Once you have composed your message, you will be taken to the preview page. You will then have a chance to review your post, make changes and upload photos.
  • After posting your message, you may need to refresh the forum page in order to see it.
  • Before posting copyrighted material, please read about Copyright and Fair Use.
  • We have a strict no-advertising policy!
  • If you would like to practice posting or uploading photos, please visit our Test forum.
  • If you need assistance, please Contact Us and we will be happy to help.


Learn more about in-text links on this page here