Leaves on my knockout rose bush have holes in them and white spots on them.
A picture would help a lot! Your bushes may have rose slugs, whiteflies or midges. Here is a run-down of pests to carefully look for on your roses. https://extension.illinois.edu/roses/disease.cfm
do i prune the knock out rose tree in a round shape as it grows?
Any pruning you do to the Knock Out Rose Tree as she grows will take away from her blooms production. You can lightly prune her to keep a shape you desire, just be aware that it will likely affect the blooms for one cycle.
The link in the following paragraph on this website under Knockout Rose diseases (RRD) is not working. Is there a new way to get to the information? I haven't found it. But I may not need it. I'm thinking I should give up on Knockouts and stick with Tiffany and Mr. Lincoln. To keep up with the latest studies and findings on Rose Rosette, go to this link: https://www.americanhort.org. Save it to your favorites so that you can go back over and over again, there is a lot of great information at the website. - See more at: https://www.gardeningknowhow.com/ornamental/flowers/knockout-roses/knockouts-have-rose-rosette.htm#sthash.vElhSb7c.dpuf
The leaves are turning brown and looking somewhat eaten... It looks like possibly from fungus. We reside in a condo complex and do not have any control of the Sprinkler system.. Also the roses are somewhat shaded by a Hydrangea tree.. now...so perhaps not getting enough sun....
I can't speak to your situation but most automatic sprinkles are set for 15 to 30 minutes which delivers only a small amount of water. Try setting out a tuna or a pet food can (straight sides) and measure the water. Roses need a minimum of one inch per week, two in hot, windy or very dry weather. On the other hand, not getting at minimum of 6 hours direct sunlight daily is a problem. The rose will lose vigor and be more susceptible to disease and insect invasion. There seems to be a lot of rose slug damage this year. Look into that as the culprit in the leaf issues. And, of course, it is Japanese beetle time so get out the soapy water bucket and sweep the beetles into it twice daily. They are voracious rose leaf/bud eaters. More on rose slugs follows. You can expect another generation of them to appear in mid to late July. https://www.gardeningknowhow.com/ornamental/flowers/roses/rose-slugs.htm
I water regularly Nd pot has good drainage. I don’t think I’m overwatering, as it’s been hot, and it is in a pot. What else causes yellow leaves? Any treatment ideas? It is looking worse, by the week...
Oh, a picture is worth a thousand words! I'll start by assuming this is not blackspot fungal disease. If you aren't familiar with blackspot, read up on it as it is a common cause for black spots followed by yellowing leaves. Make sure the top 1-2 inches of soil are dry before watering and then water enough so a bit of water comes out the drainage holes. You want the soil moist, not wet. The other issue that comes to mind is nutrient deficiency, particularly low nitrogen. Roses are heavy feeders and need a regular schedule of fertilization. Follow instructions on the fertilizer container. If you routinely water so lots of it runs out the drainage holes, you are washing out soil nitrogen. Phosphorus and potash move through soil much, much slower than nitrogen. Lastly, did you use good potting soil? If you planted using yard soil or bagged topsoil, that's a problem and you should repot using bagged "potting soil". These are specially formulated for growing in containers. I'm including a link to an article that discusses many rose diseases. https://extension.illinois.edu/roses/disease.cfm
Roses don't bloom if they are stressed or if they don't get enough sunlight. While you will get some blooms with 5 hrs of direct sunlight, roses prefer 6-8. Are you using a low nitrogen fertilizer? Look for something that has an NPK ratio of 1-3-1 or similar. (e.g. 4-12-6) Too much nitrogen favors leaves over blooms. Roses require an inch of water weekly, 2 inches in hot weather or sandy soil. As temps cool down, roses often pick up their blooming. Look for flower buds. Are they being devoured by insects? Some rose pests are tiny and hard to see but they can cause real damage. Smaller insects seem to favor flower buds and new leaves. Damage may cause the buds to fall off or fail to open. Are there vigorously growing canes that get taller than the rest of the plant; are these coming from the ground instead of the main stem? If yes, kept these cut off at ground level. They are called "blind shoots" and are using up a lot of your plant's energy. One last thought: has the rose sunk since you planted it? It is very important that the base of the rose be above ground.
I've linked to articles that may be helpful:
https://ask.extension.org/questions/135664
https://www.gardeningknowhow.com/.../knockout-roses/care-knockout-roses. htm
We trimmed the roses the way we were told by a friend but now the bush Kate grown into long stalks,would appreciate help with when and how to trim them thanks
Roses are pruned annually in early spring before they leaf out. They benefit from hard pruning and reward the gardener with vigorous new growth. New growth blooms best in Knock-Outs. However, if you miss a year, don't fret. They will still bloom but may get taller than desired. Remove all growth that isn't at least pencil width. Cut back old gray canes to the base - all the way down. Remove all stems growing toward the center. Leave 5 major canes about 2 ft high that are growing away from the center. It may sound drastic but it works. The goal is an open center that sunlight can penetrate and air can circulate. Other vital parts of routine rose care are full sun, fertilizer and weekly water. Regardless of the time of year, always remove dead, damaged, diseased and dying canes right away as they invite disease. This includes 2 canes that are rubbing against each other. Rubbing forms a wound where germs can enter. Remove one of the two canes. https://www.gardeningknowhow.com/.../knockout-roses/prune-knockout- roses.htm