Methods of Fertilizing Roses
Do What's Easiest for the Job at Hand

By Kitty Belendez 
Master Rosarian

When I first started growing roses and only had a dozen plants, I used Ortho granular fertilizer that only required that I sprinkle on 1/4 cup around each rose bush and then water it in afterwards. This particular granular also included a systemic insecticide. This method of fertilizing roses was fine for monthly feeding of just a few bushes, but after a couple years when I had accumulated over 50 bushes, the granular fertilizer was becoming too expensive to use. And I did not like putting all that insecticide into the soil every time I fed my roses. I wondered what it was doing to my worm population.

Then I discovered the water soluble rose fertilizers such as Miracle-Gro, Grow More, and organics such as fish emulsion. This seemed to be less expensive and faster acting than the granular, but I had to mix them one tablespoon per gallon of water and carry one bucket at a time around to each rose bush. It didn't take long to find out that this method of feeding 50 roses was A LOT OF WORK. In fact, all this lifting and carrying eventually caused an injury that required me to have major surgery.

Soon, I heard about the siphon device (Hyponex or Siphonex). This $10 device attaches to your faucet, with a tube that extends down to a bucketful of fertilizer that has been mixed at a 16:1 ratio. You then attach your garden hose to the siphon device and when you turn on the water the concentrated fertilizer is then supposedly sucked up and delivered to your roses at the correct concentration. This method of fertilizing roses worked pretty good until I had collected over 100 rose bushes. However, the siphon had a tendency to get clogged up whenever I used fish emulsion, and I had to make sure that the device was thoroughly cleaned out after each use. Also, I was never really convinced that the device was always delivering the correct ratio of fertilizer to my roses, since I have a very high water pressure (everybody's is different), and the water pressure would drop drastically as the device would start to clog up. I finally got fed up when I just could not keep the device unclogged, even though Bob frequently took it apart and cleaned out the siphon hole with a tiny needle. Still, the siphon device is a good tool for feeding less than 50 roses with only water soluble type fertilizers such as Miracle-Gro. But I do not recommend using it for dispensing fish emulsion or other thick fertilizers.

THE SUBMERSIBLE PUMP  <click here for more info
Well, a few years later, I suddenly found myself with 350 roses. I had gotten frustrated whenever I tried to fertilize my roses with the siphon device and had to fight with it all the time to keep it free flowing. Then I heard that others were using a submersible pump (also known as a "sump pump"). This sounded intriguing, and for $60 I decided I would give it a try. I had heard that it was a real time saver, and with 350 roses I surely needed to save some time.

With the sump pump, you mix up your water soluble fertilizers at the appropriate ratio, according to the directions on the package, in a 30 or 50 gallon can. So, for a 30 gallon can, you will mix 30 tablespoons of Miracle-Gro with 30 gallons of water in the can. The pump is electric and so must be plugged into an electrical outlet. We use an outlet in our garage, and since the cord on the pump is short, we need to also use an extension cord. Before fertilizing your roses, do a "count test" to see how many seconds it takes to fill up a one gallon bucket. For example, I count to 8, which is how long it takes for the pump to dispense one gallon for my hybrid teas, and count to 4 for a half-gallon (or 2 for a quart) to be dispensed to the miniature roses. Depending on the size of your yard, you may need to use a long garden hose to reach all your roses.

A friend gave us a gigantic 55-gallon drum that we are now using to fertilize our roses. We have to fill up this drum three times to feed all of our 350 rosebushes (more than half are miniature roses). The submersible pump is an incredible time and work saver if you have more than 100 roses to fertilize. It takes us just one hour to feed all of our roses. It was taking me at least twice that long with the siphon device. We use it to dispense Miracle-Gro, fish emulsion, iron, and even epsom salts, with no clogging problems. Every time I use the pump to fertilize my rose garden, I marvel at its efficiency.

There are other options for fertilizing your roses. Some people use a hose-end sprayer. I do not like these for several reasons. First, I prefer not to foliar feed my roses, which is what you will do if you use the hose-end sprayer. I have never had good luck with foliar feeding, and when I did, the foliage got burned. Secondly, I do not trust the accuracy of this type of dispenser, because I am not certain that my roses are getting the precise ratio of fertilizer. And third, with 350 roses, I would be constantly filling up this sprayer, which would be too time-consuming. I suppose that a hose-end sprayer could be useful for people who only have a few roses, but I would be careful to only feed in the coolest part of the day to avoid foliage damage.

These sprayers are meant for application of pesticides, and I do not recommend that they be used for fertilizing your roses. You want to get the fertilizer quickly to the roots, and with the pump sprayers you have to do a lot of pumping which is also a lot of work.

So now we have come full circle back to hand distribution of granular rose fertilizers. For the rosarian who just does not have the time to feed their roses on a regular basis, a time-released fertilizer such as Osmocote 14-14-14 may just suit your needs. There are a number of different formulations available, such as 3-month, 6-month, and 9-month. These fertilizers need to be applied by hand, and they will slowly break down and dispense the fertilizer over a long period of time. However, they are very expensive, especially if you have a lot of  roses and you buy the small packages. Osmocote is considerably less expensive when you buy it in bulk 50# bags. Be sure you are buying the correct N-P-K for roses. Read the label on the rose fertilizer to see what the product contains.

We still have to apply the organics such as alfalfa pellets, blood meal, kelp meal, and compost by hand. But, with all the time I save with my pump, I have time left to feed my roses lots of organics, too. They love it!

© Copyright Kitty Belendez. All rights reserved.

This article was originally published in "Rose Ecstasy," bulletin of Santa Clarita Valley Rose Society, Kitty Belendez, Editor.

Photos © Copyright by Kitty Belendez

For questions about Santa Clarita Valley Rose Society, contact:
Rose Society


Updated January 5, 2016

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