Jack Falker is a rose enthusiast who gardens in Minnesota. Minnesota–in case you don’t have the USDA Hardiness Map memorized–is entirely a cold climate state, consisting of Zone 3 and 4. (Okay, there is a teeny bit of Zone 5 in the most recent map, but still.) One can’t grow roses in Minnesota without knowing how to grow them in a cold climate, and Jack grows a lot of roses.
Jack gives his roses a potassium feast every fall, starting six weeks before the first hard freeze. (He started this year on September 16th.) He first read about this in a rose book by Suzy Bales, and had the concept confirmed by a retired soil science professor, who assured him that “… winter hardiness is one of the most important functions of potassium”.He dissolves one tablespoon of muriate of potash into three gallons of water, and gives each rose a gallon for each of those six weeks before they go dormant. As Jack says, “Potassium blocks the growth-promoting effects of nitrogen and phosphorous, thereby hardening the canes in time for winter.” As the canes become more hardened, they start to turn red, as you can see in the photo at the very top of the post that Jack supplied. I have been intrigued by this and was eager to try it on my roses. There was only one thing that stopped me:
Where do I get muriate of potash?
Jack gets his from farm supply stores, and “I define a farm supply store as a place that sells bulk fertilizers to farmers, not someplace that sells bird-seed to bird watchers,” he says. I called my local Tractor Supply and Agway, and neither of them had something by that name. Well, what exactly is muriate of potash? Turns out it’s potassium chloride, plain and simple. Maybe if I had asked for it like that, those stores would have told me they had it. But in the course of researching exactly what it was, I discovered Amazon sold it in four pound bags. Problem solved!
I’m getting started a few weeks later than Jack, and I’m not sure I’ll get six weeks in, but some is better than none. And I’m going to mix it up in my trusty Rubbermaid watering can, and not in a 60-gallon trash can as he does. I think I’d have to grow a lot more roses to make a set-up like that worthwhile. And I’ll make sure to wear old clothes, as he says the mixture stains red, though it eventually washes out.