Return to the Roses Forum | Post a Follow-Up

 o
Rainbow Knockout Rose HELP

Posted by nadarashdan Ohio (My Page) on
Thu, Jun 26, 14 at 10:43

Hi there,

So I am a beginner with gardening. I picked out a few knockout roses from Lowes, the double red ones - and those are doing great with very little maintenance. That made me ambitious, so when I found a couple of Rainbow KO roses on sale at Lowes for $5- I purchased two 1-gallon pots. They were not doing so well when I bought them, which explains the $5 price. They had powdery mildew which I sprayed with a DIY oil vinegar detergent water mix, this turned the leaves blackish but removed all the mildew. Some roses were starting to rebloom but the the stem, stalk, leaves, and older blooms just looked so bad that I just decided to cut everything back. I cut off all the leaves, the buds, everything. It was very unsightly and I could not take it anymore. Now I am wondering if I made a mistake. It was probably about 2 1/2 feet tall when I bought it but miserable looking and shriveling now I have two stalks with branches branching out, no leaves or flowers, that are about 1 foot tall with thorns but green. My thoughts were honestly to give it a chance to grow healthy - a new start. Do they have a chance??


Follow-Up Postings:

 o
RE: Rainbow Knockout Rose HELP

Are they still in the pots? I would wash what is left really good to get the vinegar and oil off them. Oils will burn the leaves if the temps are over the mid 70's. Since they do not have leaves, the canes are going to get sun burnt. Partial shade should help til they grow new leaves.

Next time, I hear spraying the foliage with water is all you really need for the mildew, that and time for the plant to grow later and better throw it off on its own.

Save the vinegar for weeds. Roses are pretty tough, bet these two come back.


 o
RE: Rainbow Knockout Rose HELP

No, they are not in their pots. I planted them the day after I purchased them about 2 weeks ago. I have washed them down, I do regret that vinegar mix! Hope you're right about them coming back!


 o
RE: Rainbow Knockout Rose HELP

Vinegar is a herbicide! Oil and soap can burn foliage in hot weather. Please do not use these jackleg kitchen-pantry mixtures that you might see on the internet. In the eastern US, powdery mildew is usually not a severe problem and is easily controlled.

Probably your plants will recover just fine if you are patient and do not "help" them too much. Just water thoroughly every 4-7 days depending on the weather and when the soil surface is dry-ish. Put down a 2" layer of mulch.Don't fertilize until they are growing out happily, and then use less than the label recommends. Best wishes, and come back for advice any time.


 o
RE: Rainbow Knockout Rose HELP

If they have no leaves and it is hot, it would help to give them some shade for the heat of the day, not super pretty but a plastic chair over the plant is an easy way.

There are some home mixes that are probably fine on your roses, but if you find one you want to try, ask here first. Usually some one has already tired it and either knows it works or it doesn't. There are a lot of "organic" mixes posted out there but people often leave out big details on usage and side effects on different plants and how they effect the long term overall health of your garden.

Seems like many of the rose issues we have on my coast could be helped with a spray of water no need for other additives :)


 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 Roses 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.
  • Please review our Rules of Play before posting.
  • 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