Roses are just plants and have the same nutritional needs as other normal plants. The formulas for MG and MG for Roses are very similar .

As long as it approximates the nutrient ratio beneficial for the plant type, it's all the same. As Ralph Moore used to love to say, "Roses can't read." "Close enough" is often good enough. We live in an age of specialization. Many people don't care, don't have the interest, won't take the time to educate themselves to find out there are really only a handful of fertilizer and pesticide types. The manufacturers capitalize on it so they can sell you ten different fertilizers for ten different kinds of plants. But, when you become familiar with them, you'll find you can get away with using something like a Gro Power Plus on everything and it works just fine. Kim

Here is a link that might be useful: Gro Power Plus

The University of Illinois Extension recommends 10-10-10 or 12-12-12. I usually buy 13-13-13 from Blain's Farm and Fleet when it is on sale for $10.99 for a 30 lb sack.

Here is a link that might be useful: Rose Fertilizer

Why do you think it needs fertilizer? KOs are very hardy. Are they not blooming? I have never fertilized mine and they are 4 ft tall and very full. If you feel it is really needed, we use Milorganite on our summer blooming plants. Its good stuff and a deer deterrant (still trying to prove that theory).

How much fertilizer is needed depends on the soil type. Soils with substantial clay or organic content hold nutrients. Sand (especially) and silt do not. Roses in very sandy soil can use a dose every 4 weeks. Roses that are heavily pruned each year need more fertilizer than those that grow as they will. Repeaters need more than once bloomers. I have a once bloomer that has grown larger and bloomed heavily for twenty years with no fertilizer or irrigation. It is on a clay bank.

NPK ratios from 1-1-1 to 3-1-2 are suitable. Roses use more nitrogen than anything else. If you have pretty good soil and get it tested, chances are the report will say you need only add nitrogen on a regular basis. Mulching with yard waste may provide enough for shrub roses like KO.

We have an exhibitor in our rose show that has won all the national trophies to be had--he uses 10-10-10 on his roses.

I got a soil test and figured out that I can use even cheaper fertilizer. And, because I have clay soil, my roses grow well with just a fraction of the fertilizer used by those who roses in well draining sandy soil.

This post was edited by zack_lau on Sat, Jun 8, 13 at 15:40