Hello Everyone!
I am back after working the pass few days on a sod farm in RI – it was a great experience, and learned a lot.
The problem you have, cdepaor/Colin, is a common fungal disease
called rose black spot, and here's what you do -
1 – You MUST pick up all of the fallen leaves as well as those about to, and put them into the garbage!
2 – If you have mulch under the plant(s) remove from area and place in garbage and replace with fresh straw – pine straw is best.
3 – Prune all the plants so that sunshine and fresh air will reach every leaf.
4 – Remember when you water plants, especially roses, don't wet the leaves.
I would like you, cdepaor/Colin, to really chase this problem away by painting every speckled leaf with my 'Black Spot Mix', thats if you really love roses – it's worth the trouble.
Black Spot Mix -
You'll need 15 tomato leaves, 2 small onions and 1/4 cup of rubbing alcohol.
Chop the tomato leaves and onions into minced pieces, and steep in alcohol overnight. Use a small, sponge-type paintbrush to apply the mix to both the tops and bottoms of any infected rose leaves. This will end your problem for the entire summer – just check once a week and apply my 'KO' mixture below whenever it rains heavily.
The plants that are free from the disease should be given my Fungus 'Knock-Out' Mixture.
Knock-Out Mixture -
1/2 cup of molasses, 1/2 cup of powdered milk, 1tsp baking soda, and 1gal of warm water.
Mix molasses/milk/soda into a paste. Place mixture into the toe of a nylon sock/stocking and let it steep into the 1gal of warm water for 3-4 hours. Strain and place into a sprayer – spray all over your roses and it can be used on your other perennials, too. Use on dry days between rains and repeat every two weeks if you want the best this mix has to offer. 