What is this on my rose bushes?

Question

I don't know what kind of roses they are, but there are only 2 layers of petals. They have been unbelievably healthy until last week. I noticed there were white stuff on the leaves and then they would turn yellow and brown then die and fall off. The top of the bushes are great, the new growth has just turned green but the bottoms are bare. I've picked up as much of the leaves as I could (mulch is around them) and started spraying them with a fungicide. No more white but the leaves are still turning brown and yellow and dieing. Am I doing the right things? Is there anything else I should do? If it helps at all I live in Florida. The sprinklers are set for 7am only every other day. Also some of the buds are really small and then die fast, right after blooming.

Answer 1

The white stuff is powdery white mildew. This is going to be a constant battle once it set in. But, it can be controlled.

When you water, do not get the foliage wet. That promotes the fungus growth. A good product for fungus and mildew is neem oil. Ask for it in a specialty nursery (they may not have it at Home Depot).

Also, when you use the stuff, make sure you get both sides of the leaves (front and back). You can't readily see the fungus on the back, but you'll see it as dead leaves on the front.

Also, remove/replace all of the dead leaves and mulch around your plants. Throw it in the garbage or burn it. Once you get mold and mildew spores, they can blow up from the leaves/mulch and end up right back on the leaves.

As far as the blooms, are you pruning the plant after the bloom? If you just let the plant go, it will get really bushy and give small flowers. If you prune correctly, you will get less but bigger blooms. To prune correctly, cut the stem with the dead rose just above a leaf stem with at least 5 leaflets on it. The bud that forms at the base of the leaf stem will form the stem for the next rose and it should be bigger than if you just let the plant do its own thing.

Answer 2

First of all, you shouldn't be watering your roses with a sprinkler. You should be using soaker hoses. Even in the morning, getting the foliage wet in Florida invites fungal diseases. Pick the dead leaves off the bushes & destroy them as well as any leaves that have fallen to the ground. Continue spraying with a fungicide. A systemic one like BannerMax will work the best (although it isn't cheap)

Answer 3

you're good on your 2nd hypothesis. Your rose timber are great nutrition for many bugs and the carnivorous spiders are as a result feasting on the bugs on your roses. you ought to % out the insect it is inflicting the wear. no remember if it incredibly is a caterpillar (small green caterpillars attack rose leaves) you ought to use Bt - a organic and organic insecticide that may not injury the spiders. no remember if it incredibly is another form of insect you ought to use another insecticide, even though it incredibly is going to additionally kill the spiders.

Answer 4

Yep they are all right, I just wanted to add that if you do spray with Neem make sure you spray in the evening because it is an oil so the hot sun on it may burn the plant.

Answer 5

Paul gave you all the right answers! All, Paul's answer es included cleaning up Powdery Mildew! gggggggggggggoooooooooo! for this answer

Answer 6

Hi there,

Check out this link:

http://www.backyardgardener.com/rose/rose5.html