Peninsular Rose Club - No-Clog Fertilizer method

The No-Clog sprayer approach to fertilizing

by Garry Brust

June 2004
It’s late spring in Victoria - stop and think a minute about what happens to granular fertilizer when you spread it around your roses. How long did you spend watering it in?
If you answered 15 seconds, you’re more conscientious than most. The tendency is to think to oneself “the next time it rains, it ’ll get watered in.”
Guess what - we’re not likely to see appreciable rainfall from June 1 until October, so your fertilizer for summer growth won’t be delivered to the roots of your roses until Fall, when you want to start hardening them off for Winter.
Here’s my contention: applying dry fertilizer is a waste!
Would you rather deliver fertilizer to the roses’ roots when it’s needed, and with little or no extra work? My secret to effective fertilizing is to use a hose-end “No-Clog” fertilizer sprayer, such as sold by Miracle-Gro and Plant Prod and water directly into the root zone.
Let’s get one thing out of the way - the first job is to build a good soil with organic material (compost and manure). We’ll presume you have done that. But roses are heavy feeders and compost alone doesn’t provide enough for vigorous growth, so most rose growers add supplemental fertilizer in the growing season. A poll of our club showed the following types used:
• 28% members use organic liquid and dry
• 40% use granular
• 32% use soluble Miracle-Gro or Phostrogen
The “No-Clog” sprayer consists of a plastic jar, with a lid that has both a male and a female garden hose fitting. Inside the lid are two small holes that allow a portion of the water stream to “jet” down into the jar, and return, with fertilizer, into the water stream coming out the male fitting. You can use the supplied sprinkler attachment on the jar for hand watering, or you can unscrew the sprinkler head and screw a hose onto the output, for connection to a drip, soaker hose or other watering system.
What you do
The plan is to add dry fertilizer to the jar, hook up the hose, and water your roses. As you water, the fertilizer will be dissolved and delivered to the roots.
Two methods:
1) Spray application: You can set the jar with the sprayer beside the rose, and leave it there for one minute while you deadhead and check for disease.Then move it to the next rose. Once you have done 8 roses, come back down the row, this time setting the sprayer on the other side of the rose. This way, each rose gets 2 minutes of watering (approx. 20 liters depending on your water pressure), and the dilution of the fertilizer will equalize out per rose.
2) Drip application: This one’s even easier - just hook the jar up to a drip or soaker hose watering system and let it run for 4 - 5 hours. The fertilizer will be delivered to each plant equally along with the water. When the water is shut off, a sudden release of water at the back of the sprayer is normal as the sprayer is designed to release internal water pressure when not in use. It may be useful to put a pressure regulator in the line before the sprayer, to limit the back pressure.
Here are the advantages:
1. The sprayer saves money because no fertilizer is wasted, all nutrients are in a soluble state when applied and can be immediately used by the rose.
2. It saves time because once the sprayer is loaded one has to make only one trip through the garden.
3. If used in a drip system, all plants relying on drip will get some nutrients.
4. When delivered as a solution, there is little or no chance that the fertilizer will “burn” roots, because burning is caused by dry fertilizer drawing moisture out of the roots.
The siphon rate out of the container appears to be about 15:1 at my home water pressure. That means that most of the jar’s contents will have been dispersed in 15 minutes
I use the sprayer at the following rates which are based on the rates recommended by the manufactures
• Granular or beads (20-20-20, don’t use Osmocote or other time-release formulas) - fill the jar with about 4 cups for eight average size rose plants
• Miracle-Gro 20-20-20 or 10-30-10 for eight plants - 8 tablespoons
• Phostrogen 10-10-27 for eight plants - 8 teaspoons

Testing with a Drip System:

During the past two days I have tried to determined how long and how much water is required to dissolve 4 cups of beaded fertilizer in the sprayer. Here are the results:
1. The sprayer was hooked up to the front yard drip system for five hours during the last two days
2. About one quarter of the original volume of beads remains and after allowing the remainder to soak for a few hours, my meter indicates there is still considerable fertilizer salts remaining
3. I do meter the volume of water delivered to each drip system so I have determined that 120 liters of water has agitated the beads during the five hours of watering. (The agitation of beads can be observed through the translucent container and it appears to be about what one should expect from a blender on low speed)
4. Conclusion: soaking the beads before use in sprayer should speed up the dispersal of nutrients in watering system. In addition, considerable amounts of water and time are required to dissolve beads.
It is unlikely the anyone using the conventional method of throwing beads around plants is watering in four cups of beaded fertilizer with more than 120 liters of water. Therefore, throwing fertilizer on the ground appears to be wasteful and inefficient.

Potash (K) and Phosphate (P)

Our soils on the West coast are frequently deficient in potash and phosphate. I use about 1 kg of sulphate of potash per year for the potted vegetables. Prior to this year I frequently had potash and phosphorous deficiency symptoms. Last fall I learned that many commercial growers add 3 grams of potash and 3 grams of phosphorus (1 gram triple superphosphate) to each liter of potting soil. I tried that this year and to date my previous problems have not occurred. My research last winter seems to indicate that weak acids in a growing media assist in the dissolving of granular fertilizer.

Salt and Soil:
One thing I have talked about before is salt levels. We want to avoid building up the level of salts in the soil, and particularly in pots and containers, where salts can accumulate. Fertilizer contains soluable salts, and there is a range of concentrations that plants do well in. Too much of a good thing however, can damage the plants. Manure tea and granular are highest in salts, Phostrogen is the lowest.
High-nutrient fertilizers like 20-20-20 have more salt, but because you apply half as much as a 10-10-10 for the same fertilizer value, the salt increase in the soil is less.You can purchase a meter that measures the salt content of soil, and keep records of what meter readings correspond to the best performance of your plants.

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