I have been asked about my mulching and watering practices that I use to deter black spot on my roses. First of all, I choose disease resistant roses, David Austen roses, Don Juan and Blaze, Peace, a few knockouts, Queen Elizabeth, Zephren Druin are all good but I also have a few tea roses and unknown hybrids that are a little more susceptible.
Second, all watering except for natural rain comes through a soaker hose I have attached with a timer for my cutting garden where most of my roses grow. This prevents splashing on the leaves and minimizes the spread of black spot.
As for mulch, I clean out all last year’s mulch by January and prune the roses as needed. Then, because some of my flowers re-seed themselves, I hold off on the mulch until any new plantlets have declared themselves. This ensures my larkspur, bachelor button, and any new Rudbeckia and cone flower can set seed. Then in May, I apply a fresh covering of live oak leaves at 3-4″. I use live oak leaves because that is what I have and although live oaks are evergreen, they do “shed” a truckload of old leaves in the spring which is exactly when I need them. Anything I don’t use goes to compost with a generous helping of bloodmeal to help them break down into great compost by fall.
That usually does it but sometimes our springs are a little soggy like this one has been and we didn’t have even one hard freeze this year so fungus and insects are at a high point and feasting on my roses especially. Then I do use a fungal spray which also deters feeding insects. Here is the recipe:
- 4 tsp. Baking Soda
- 1 Tbsp. Horticultural Oil (I use a light year-round oil)
- 1 Gallon of Water
Mix and apply to the leaves with a pump sprayer (pictured below) or a regular spray bottle. I use both. That’s it. The baking soda takes care of the fungal infections and the horticultural oil encourages the mix to stick to the leaves and also deters the bugs. I have used commercial sprays in the past for both fungal and pest control and I can truly say that going organic has not reduced my ability to control these garden problems. Plus, when I see a tomato (also planted in my cutting garden) I can eat it right on the spot like an apple which is my favorite way to eat a homegrown tomato.
I keep the green spray bottle near a struggling crepe myrtle that is having a problem with big white nasty aphids. I have transplanted this tree to 3 different areas as my garden has grown and it is now in a spot that I like but it does not have as much sun as these little trees like so it has been susceptible to these bugs that came in on some azaleas from the nursery. This is what they looked like a few weeks ago but I am glad to say that most of them are gone.
So that’s it. Water and feed your plants and add compost at least once a year. Strong healthy plants are the best defense against an invasion of bugs or disease.
Organic Gardening and remember to “bee” positive!
P.S. BTW the baby robins are all doing well. Mom and dad are flying their tail feathers off to feed the triplets and this is the sixth day from when they hatched. Their eyes are open today and they are looking less like tiny dinosaurs and more like birds. I will post some pics of the little family tomorrow.