Water-soluble fertilizers can be mixed at different strengths, and can be applied as a soil drench or as a foliar spray. The soil-drench is an effective way of getting fertilizer down to the roots, but will also flow right through. Add enough soluble fertilizer to make it half strength generally 15 Tbsp. Let it sit for a few hours to a couple of days. Apply one gallon per bush.
Foliar sprays are useful to beef up disease resistance through the season.
There are now a number of products that try to combine the best of many worlds. The Puyallup Rose Society s fertilizer mixes both organic and inorganic materials to provide a wide assortment of minerals. They might be a subject for a future article. But for most of us, seek a common sense combination of ease and expense, and enjoy your time with your roses. The fertilizer industry, even the organic side of it, faces environmental questions that should be part of our decisions as to which products we use.