Sick Rose Bushes - Ask Extension
I have two rose bushes that bloom, but they don’t look healthy. Can they be saved? I included pictures of spots on the leaves, holes in the leaves, ...
Knowledgebase
Sick Rose Bushes #879673
Asked July 31, 2024, 10:47 PM EDT
I have two rose bushes that bloom, but they don’t look healthy. Can they be saved? I included pictures of spots on the leaves, holes in the leaves, and what looks like a type of berry that is forming. Both bushes are surrounded by weeds, have full sun, and get watered when it rains. They are established plants. Can you give me advice on how to care for them?
Eaton County Michigan
Expert Response
Good Morning,
The insect feeding holes--likely made by Japanese beetles or Rose chafer beetles--can weaken your plants. (Japanese beetles when in their grub stage can also wreak havoc on your lawn.) Here is some information on these beetles:
https://www.canr.msu.edu/resources/japanese_beetles_e0010turf
https://extension.umn.edu/yard-and-garden-insects/rose-chafers
If more than 1/2 of your rosebush is dead, you may not be able to revive it, but here are some steps you can take to try to revive it:
1. Remove weeds from around your rose plant as far as 36 inches. Rake old leaves and other garden debris from around the base of the plant and destroy them.
2. Prune out dead wood by cutting dead branches back to the point where they meet a main stem or point of origin. If the dead limb goes all the way to the ground without meeting a main stem, prune it at ground level.
3. Add manure or compost. Gently work two shovels of well-composted manure or compost into the top inch of the soil around the roots. This will enrich your soil.
4. Fertilize roses regularly starting after the first round of flowering using fertilizer that's formulated for roses. Moisten the soil to protect the roots from burning and apply the fertilizer according to the package instructions or following the recommendations of a soil test. Stop fertilizing late in the summer to prevent new growth as the plants prepare for dormancy.
5. Conduct a soil test. Roses requires certain soil conditions which your soil may not be providing. Self-mailer soil test kits from the Michigan State University Plant and Pest Diagnostic Lab are available. You can obtain them at the link below. Full instructions are there and also come with the kits. The cost is $25. The Lab will make recommendations for any needed soil amendments.
https://shop.msu.edu/product_p/bulletin-e3154.htm
5. Mulch around plants. Apply 2-inch-deep layer of mulch around the base of the plant, extending 6" past the root zone. Leave a 1-inch space between the mulch and the trunk of the rose to prevent potential diseases from spreading to the plant. Keep it evenly moist until new growth appears.
Like many fungal diseases, black spot can spread rapidly when
diseased leaves fall on the ground. Removing infected leaves before they drop off the plant or right after they fall will help keep the disease from becoming a major outbreak. Clean up all fallen leaves as well.
April_2017.pdf (msu.edu)
Rose Diseases (Outdoors) (psu.edu)
To get a firm diagnosis you can submit a sample for a small fee.
Plant & Pest Diagnostics (msu.edu)
The rose hip is the accessory fruit of the various species of rose plant.
I hope this helps. Thanks for using our service.
The insect feeding holes--likely made by Japanese beetles or Rose chafer beetles--can weaken your plants. (Japanese beetles when in their grub stage can also wreak havoc on your lawn.) Here is some information on these beetles:
https://www.canr.msu.edu/resources/japanese_beetles_e0010turf
https://extension.umn.edu/yard-and-garden-insects/rose-chafers
If more than 1/2 of your rosebush is dead, you may not be able to revive it, but here are some steps you can take to try to revive it:
1. Remove weeds from around your rose plant as far as 36 inches. Rake old leaves and other garden debris from around the base of the plant and destroy them.
2. Prune out dead wood by cutting dead branches back to the point where they meet a main stem or point of origin. If the dead limb goes all the way to the ground without meeting a main stem, prune it at ground level.
3. Add manure or compost. Gently work two shovels of well-composted manure or compost into the top inch of the soil around the roots. This will enrich your soil.
4. Fertilize roses regularly starting after the first round of flowering using fertilizer that's formulated for roses. Moisten the soil to protect the roots from burning and apply the fertilizer according to the package instructions or following the recommendations of a soil test. Stop fertilizing late in the summer to prevent new growth as the plants prepare for dormancy.
5. Conduct a soil test. Roses requires certain soil conditions which your soil may not be providing. Self-mailer soil test kits from the Michigan State University Plant and Pest Diagnostic Lab are available. You can obtain them at the link below. Full instructions are there and also come with the kits. The cost is $25. The Lab will make recommendations for any needed soil amendments.
https://shop.msu.edu/product_p/bulletin-e3154.htm
5. Mulch around plants. Apply 2-inch-deep layer of mulch around the base of the plant, extending 6" past the root zone. Leave a 1-inch space between the mulch and the trunk of the rose to prevent potential diseases from spreading to the plant. Keep it evenly moist until new growth appears.
Like many fungal diseases, black spot can spread rapidly when
diseased leaves fall on the ground. Removing infected leaves before they drop off the plant or right after they fall will help keep the disease from becoming a major outbreak. Clean up all fallen leaves as well.
April_2017.pdf (msu.edu)
Rose Diseases (Outdoors) (psu.edu)
To get a firm diagnosis you can submit a sample for a small fee.
Plant & Pest Diagnostics (msu.edu)
The rose hip is the accessory fruit of the various species of rose plant.
I hope this helps. Thanks for using our service.
