Help with my knockout roses!
Hi and thanks in advance for any advice! I planted five knockout rose bushes at the beginning of the summer and so far I've lost one and it looks like another is on its way out. I live in the Dallas, TX area and all the roses are in the same garden bed. They get full morning sun with some afternoon shade and I have them set up to water automatically with my sprinkler system. As you can see in the picture below the leaves are turning brown and dying. It just rained last night but normally they are crunchy not wilted. If you look at the bottom picture on the far left you can see the rose bush that has slowly died over the course of the summer. It did the same thing turning brown and dying a cane at a time until I finally gave in and pruned it to the ground about a week and a half ago. At that time the four remaining bushes all looked like the healthy one in the picture. Over the last week and a half this next one has deteriorated rapidly! There doesn't seem to be anything eating the leaves. All five get the same water/sun/fertilizer and the other three still look great. I did have some problems with black spot in my front flower bed that has mostly cleared up. I found a couple leaves on these back roses but I pruned them right away and they didn't seem to notice. Could something be attacking the roots? Is there something else I'm missing? Thanks and sorry for the length!
Comments (9)
Related Discussions
whats wrong with my knockout roses ??
Comments (6)Respectfully, I have to disagree with the above prescription for water. How much water the soil can hold depends on the soil type, and how much to add depends also on how moist it is. But typically, in your midwestern location, one inch per week is adequate with high temperatures running in the 80s or low 90s. Plants could use maybe 1.3 inches with higher temps, or low humidity and wind. One inch is 4-5 gallons per square yard. With sandy soil, water less than an inch at a time, but more often (at least twice a week), as it can't retain much water. 3" at a single application is way excessive. With temps in the 80s, I water less than one inch per week and my roses never stop growing vigorously. In Florida with sandy soil and temps in the mid-90s, we watered 3/4 of an inch every three days if it didn't rain. Every gardener should have a rain gauge....See MoreMy Knockout Rose Bushes- Did I kill my rose bushes?
Comments (2)Right, don't fertilize until they have recovered and have put out plenty of leaves. Bloom Buster is the wrong kind of fertilizer--regular Miracle Gro or Miracle Gro for Roses is fine, or any reasonably balanced fertilizer such as 10-10-10 or 18-6-12. Watering correctly is the most important thing. Keep a 2" mulch of leaves or bark around the roses. When the soil under the mulch feels dry-ish, water thoroughly with 2-3 gallons for small plants or 5 gallons for larger, plus or minus for extremely hot or very mild, cloudy weather. Usually once a week is fine. For new plants, I divide the ration in half and water twice a week....See Moremy knockout roses have slugs!!!!
Comments (16)That's what mine do, yeah! Just some roses, not all of them, but there end up being too many to squish, because some of the roses are quite tall, too! I do use spinosad. Once. When the bees are all in for the night. I do just squish them when they aren't quite so rampant :) Edit - Oh, I do leave enough on my other roses that predators are happy. I have all kinds of birds and wasps in my yard, and toads, too. They just don't choose to pick off every rose slug, either, for whatever reason. They have better things to eat here, apparently, lol :D...See MoreNeed Help - Bugs are Killing my Knockout Roses
Comments (13)Little green worms that are probably on the underside of your rose leaves munching...(size varies from tiny up to a inch long)... Sawfly larvae are called Rose Slugs....Least toxic spray would be safer insecticide soap or similar... Spinosad is very effective just be careful and follow directions as it can kill bees... Some people pick them off there rose leaves and squish... Our curled rose slug here are mostly found on top of the leaf... But usually other types are found UNDERNEATH the leaf... Here's what our more mature rose slugs look like: The wasp eats them so he is a good guy in my book....lol...See More
7 years ago
7 years ago
7 years ago- 7 years ago
jim1961 / Central Pennsylvania / Zone 6