Dr. Don about that Neem

I sprayed it on my roses, what, a couple weeks ago ? before any signs of black spot and I see some are already getting bs. Should I spray again or wait until its been 3-4 weeks? Also it seized up my sprayer with what seemed to be a stickiness even though I always flush the sprayer afterwards with 1 gal. of water.
Any advise? Thanks much! CR

Is Dr. Don on vacation???

Cottage Rose...Neem oil will gum up your sprayer if you mix it with cold water and/or if you don't keep it agitated during spraying. I'd suggest mixing it with warm or at least tepid water and be sure to shake it well before and while using to keep it well mixed.

As far as using if for black spot the directions on my bottle suggest 2 tbs per gallon of water and spray every 7 to 14 days initially until disease pressure is eliminated. Then continue spraying every 14 days.

Hope this is helpful to you.

By the way, also remember black spot is often caused (or increased) by moist conditions so try not to water the foliage. If you've been getting lots of rain it might do you justice to prune/thin the plant so you'll increase air circulation. (If it were me I'd remove the canes/leaves that show signs of black spot and get rid of them.)

HS thanks much for the tips! :)
Will simply using warm water prevent it from sticking on the sprayer parts or do I have to clean the sprayer afterwards with something like warm water and soap?

The warm water will contribute to keeping the neem oil emulsified in the water (but yet still it's important to keep it well-mixed while using it). As always, I would recommend you flush out your sprayer with fresh water after using it, no matter what you put in it (Neem, fish emulsion, insect sprays, etc...this keeps any residue from accumulating on the various parts of your sprayer. There should be no need to use soap if you're using warm water to rinse the sprayer with. (If you use soap then that, too, would leave a residue...always just use fresh clean water when cleaning out your sprayer.)

I always spray clean water through the sprayer after each use but just use cold water. Will give the warm water a try.
Thanks again.