Roses Growing Weaker After Installing Rock Mulch

Q. I have some well-established rose bushes (15 years) in our front yard. Five years ago we converted to desert landscape and the landscaper put about 3 inches of small rock in the area containing the roses. They seem to be healthy although the density and beauty of the blooms was weaker last year.

            I've been using liquid Miracle Gro. Is there a better liquid fertilizer, or should I consider pulling the rock away from the bases and fertilize through the soil. Thanks.

 

Not the readers rose but what can happen to roses over time growing in rock
mulch and little care.

A. Miracle Gro products are fine but I would also add a separate iron fertilizer. Go to your local nursery and get a one pound canister of iron EDDHA. Follow the label directions but I find it more effective to mix in a teaspoon of the product in a gallon of water and water it into the rootzone of each plant.

Some of the Miracle Gro specialty fertilizers. Actually any of these would interchangeable. Miracle Gro might disagree
but these labels are mostly to help novice gardeners select a fertilizer for specific plants.

            Each rose should get maybe one teaspoon January – March, a once a year feeding. Although best applied early, an application will work now. They should be all right if you keep it on this fertilizer schedule. Select a product that has a big middle number. There are several different ones to pick from and I don’t know their product line off the top of my head.

This is the correct iron chelate to use in our high pH soils.

            Feed roses about every two months lightly starting January – October. However the iron is needed just once a year. Do not neglect soil improvement as well by using composts and organic mulches that decompose into the soil. Roses will really appreciate wood mulch much more than rock mulch.