Beffie
Newly Registered
Posts: 2
Joined: Mon Jul 22, 2019 6:00 pm

What is wrong with my roses??

I have 4 knockout roses that my daughters gave me for Mother’ Day. They are are still in the pots because our yard is being graded. They have started looking very ill and I don’t know what to do! I have attached a couple of photos. Can anyone help me save my roses? Thank you!
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imafan26
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Posts: 13961
Joined: Tue Jan 01, 2013 8:32 am
Location: Hawaii, zone 12a 587 ft elev.

There is a lot going on. It looks like you have some black spot, something is chewing on the leaves and I am guessing it is either snails or slugs, beetles tend to make my rose leaves look more lacy. There are crossing, dead and weak thin stems. I see some dieback on some of the branches and the yellowing which can be caused by a few other things.

Step 1 Pruning cuts
Roses should be pruned to a 3 leaf outward facing branch after each bloom cycle. Some roses deadhead themselves but most need to be deadheaded. Make sure tools are sharp and clean. Either flame the pruner blade with a torch for a few seconds after each cut or plant. If you don't have a torch, at least spray or dip the blade in alcohol and wait 90 seconds between cuts on the same plant and clean and wipe the blade, wash your hands between plants.
Prune out dead wood to healthy tissue just above an outward facing node. Any cuts greater than 1/4 inch in diameter, I will also paint with pruning paint to seal the cut. It is easier to spray some paint in a paper cup and use a cotton swab. It does not get paint all over the plant. I got this tip from the rose hotline when I had issues with dieback after pruning large branches.
Prune out weak and crossing branches.
Before frost comes, you will need to prund back to the healthiest 5 branches. I don't have a frost date, so for me it is pick an arbitrary date in January (rainy season). Roses will bloom at Christmas for Hawaii.

Knockout roses are usually short floribundas so the canes will not be as big as a hybrid tea rose, but they are supposed to be more disease resistant.

2. Roses are heavy feeders
You need to feed roses heavy after each bloom cycle and when roses are actively growing. I use a slow release fertilizer and side dressings. Occasionally, I will also use MG water soluble fertilizer,usually because I am feeding the orchids as well.

3. Roses are hard to grow organically
a. Slug bait and snail hunts daily
b. If there is a prolonged period when it is wet and humid, it is hard to stop fungal diseases. It helps if you select roses with glossy leaves instead of matte leaves. Space roses so they get good air circulation. Sanitation. pick up debris and remove sick leaves promptly. Systemic rose care. I usually have to use systemic rose care for fungal disease, and pest control from April - August if it becomes a problem that the predators cannot handle. After that, it is less of a problem. Plant roses near a light. There are no Japanese beetles here but we do have Chinese rose beetles and a strong street light will deter them since they feed between dusk and 10 p.m. Otherwise plan on regular fungicide sprays to prevent problem every week when humid conditions prevail. Fungicides don't work well as cure, they are better at prevention.
Underplant roses with garlic or garlic chives, marigolds, and alyssum. They attract predators and garlic deters pests.
Put out terro ant bait and control the ants especially in the Spring when the roses put on a lot of new growth.

4. Roses are fairly drought tolerant, once they are established they do fine with deep watering once or twice a week. Soil should have a lot of organic matter and drain well. Underplanting with alyssum or mulching will help to retain moisture. It is best not to water overhead, but at the base or with a soaker or drip irrigation. Potted roses need to be watered every 1-2 days. My roses are in 7 gallon pots. They are fed osmocote slow release every three months or so and about every 6 weeks with 6-4-6 fertilizer ( about a tablespoon) while they are actively growing pretty much I feed them when I prune the roses after they have bloomed. I have a couple of wild roses. Baby blanket and red ribbons. They are watered daily because they are in the part of the yard that I water every day. Since, it is the back yard where I keep my edible plants and it is dark since there is no light there, they are not given usually sprayed with anything, occasionally they get white flies and some holes in the leaves, but I also have a lot of predators in the back yard and plants that whiteflies like better, namely sweet potato, hibiscus and peppers so they don't bother the roses so much. Those roses are wild, I only cut them back when I get to them. They pretty much take care of themselves.
Frankly, they like it that way. Red ribbons climbs on my other plants and has 15 ft branches and will root themselves when they make contact with the ground. Yet, I have totally failed in trying to propagate the tea rose cuttings.

5. Protect roses from marauders. I don't have deer that eat roses, but I do have two legged thieves who try to rip off the flowers and they have stolen a few plants from my front yard as well. Dogs are generally stupid, they never learn not to follow the cat into the rose bushes or they try to take a short cut through the roses. I have a "dog fence". I don't have a dog now, but then I did have a 76 lb irish setter mix who liked to chew on orchids and bromeliads and chase. I had a light fence that would not really stop him if he really wanted to get through it but he was trained to respect the fence and not cross it. I did have to move all the bromeliads to the public part of the yard in front of the privacy fence. He still managed to find bromeliads I missed.



https://www.missouribotanicalgarden.org/ ... oblems.pdf

Beffie
Newly Registered
Posts: 2
Joined: Mon Jul 22, 2019 6:00 pm

Thank you for the suggestions! I am new to roses and need all the help I can get.

imafan26
Mod
Posts: 13961
Joined: Tue Jan 01, 2013 8:32 am
Location: Hawaii, zone 12a 587 ft elev.

Check out the american rose society pages. They have a lot of tips and some videos on rose care. Some people think roses and orchids are hard to take care of, but really once you learn what you need to do, they do better if you select the most adaptable varieties and provide for their basic needs.

https://www.rose.org/video



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