Fertilization Question Answered

Question: So--- Our roses are doing great, but it is time to fertilize for the 3rd time--- when I say fertilize, I mean the 3 in 1 product from Bio Advanced. I use the liquid form, not the granules, because it is too difficult to rake the granules in under the rose bush -- partly because of the bark that is there, and partly because my body cannot do that.

BUT-- I feel that you are aware that this liquid concentrate product is no longer available in CA (and other states). There is a spray now -- but how does that work? -- I feel that does not get to the roots ( and it is most likely missing the product that is banned). What do you suggest that I and other people use now?

Thank you

Marsha Willard, Trilogy, Rio Vista 

Good morning, Marsha, 

First of all, I'm against using any and all systemic fertilizers. They are indiscriminate insect killers, and their poisons remain in the plant’s cell structure. So any of the numerous bugs, birds, and amphibians that feed on the pests ingest the poison. That's probably why the 3-in-1 solution you were using is now banned. Yes, the bees eat the poisoned rose pollen and die.

I'm not sure how you apply the fertilizer. Through a drip system? I'm not a big fan of drip irrigation for roses in a backyard setting. Partly because I want to stay in touch with what's going on down at the bud union, so I hand water and feed with whatever fertilizer is on sale. I do like to add fish emulsion or kelp fertilizers, as any product that comes from the ocean will contain all the micro nutrients you will ever need. In addition, I apply alfalfa pellets two or three times during the season. It's a source of nutrients, although a relatively small one. However, it contains an alcohol (triacontanol) derived from its husks, which can lower the alkaline-leaning water that you are now probably using to water your plants. One of the reasons why roses look so good in the spring has to do with all that acid-leaning rainwater they get then.

You mention digging in the fertilizer. It's my practice to grow roses at the bottom of a slight basin in the soil. That makes applying granulated fertilizers easy. Just sprinkle it beneath the bush and then flood the basin. The fertilizer will dissolve, and the microorganisms in the soil will transform it into a form the plant can absorb. The added benefit of flooding the basin is that the weight of the water gets pulled down by gravity more vertically causing the roots to grow lower down, thus increasing their protection from drought and, perhaps, lessening the amount of water you need to use as the water higher up is more likely to evaporate as the temperature of the soil at the surface heats up. It's good that you use mulch.

Another comment: I think we over-fertilize our rose bushes. Most of the time, I parse it out every time or every other time I water – a teaspoon per ordinary-sized hybrid tea. If I want a big display, I'll use something like 10-10-10 at a higher amount, watering the day before, and then watering the fertilizer in. Also, phosphorus and magnesium linger in the soil where whereas nitrogen and potassium (in the form the plants use) are soluble and will get used up or wash out. So, look for fertilizer with a higher nitrogen and potassium number.

One lesson I have learned over the years is to only grow the number of roses you can give quality care to. Select the ones that have given you the most pleasure and give your love there.

I hope these suggestions help.

Joe Truskot, master rosarian