The following is the original formula as given
by George Hooker himself including his comments.

Long ago I gave up on the use of solid fertilizers and adding the individual ingredients to each plant. It is a tedious, time consuming method, and there is no way to get even distribution throughout the plants' root systems. Finally, adding solid materials through a two inch mulch is a pain in the neck.

The dilute solution I use distributes itself nicely throughout the root area of the plant. An important point --- no part of the root system is in contact with a strong fertilizer solution which can cause fertilizer burn. Although the fertilizer solution is available at once, the plant takes only what it needs and the bulk of the fertilizer material is absorbed by the soil particles, and stored for future use. This stored fertilizer will be leached out by subsequent rains or watering thus be available to the plant in solution form. Always member that the roots of a plant can drink, but cannot eat.

For 15 years I have grown more than 500 plants, roses, and daylilies, and recently it has been more than 800 plants. Therefore, I need an efficient and orderly fertilizing system to keep the time and labor down to a reasonable figure, and at the same time, add the desired amounts of material to each plant.

Fertilizing Method

Make up 5 gallons of stock solution:

1-2lb. coffee can of Peter's 15-30-15
1-2lb. coffee can fish emulsion
1-6oz. can Epsom Salts - Magnesium Sulfate
1-8oz. can Cygon - (Editor's note: Cygon is no longer available)
1 ounce Sequestrene - Iron Chelate
These materials are all water soluble. Water is added to the 5 gallon mark while stirring. One 12 oz. can of stock solution contains the desired amount of each ingredient for 1 large rose bush or 1 daylily clump. For miniature roses or a small 1 - 2 fan daylily clump, I use a 6oz. can of stock solution. The 5 gallons (640 liquid oz.) is enough for 53 plants (12 oz. can each) or 106 plants (6oz. can each).

Note: I do NOT, repeat, do NOT apply the stock solution to the plants.

The Actual Procedure

In practice, the job is best done by two persons - 1 easy job and 1 active job. A large garden cart (or wheelbarrow) near the bed, contains the 5 gallon can of stock solution, 3 or 4 ten quart pails, a 12 oz. can and a 6 oz. can.

Person #1 (easy job) holds a running water hose (fast enough to fill up a 10 quart pail in a minute or less) and also dips (rubber gloves) a can full of stock solution into each pail.

Person #2 (active job) lifts the full pails from the cart and pours the dilute solution into the soil at the base of each plant. By working hard, it is possible to fertilize 100 plants an hour, but 50-60 plants per hour is an easy pace and will take care of my 800 plants in two days. But in those two days the plants have (1) been watered and (2) have been fertilized for the next six weeks and (3) have been protected from sucking insects for a month to six weeks.

Of course, for the system to work, the soil should be loose and friable, as it should be anyway, so the solution will soak into the ground and not run off. Sometimes if the soil is hard, I cultivate around the base of the plants before starting to fertilize. Usually this is not a problem for I like to add cow manure in the fall or winter and also use ground corn cob mulch so the ground is receptive and the solution goes right through the mulch (no problem). Also I pour the dilute solution right into the center of a daylily clump with no harm to the foliage.

Purpose of the Components:

The 15-30-15 soluble fertilizer is a good growing compostion and the high phosphate corrects a general phosphate deficiency in the Pittsburgh area soils. Not only that, but the solution distributes the phosphate throughout the root area which solid phosphate fertilizers cannot do. If you think this is too much nitrogen, change to 9-45-15 plant starter for May 15 and July 1 application (41% less nitrogen).

The fish emulsion adds hormones, vitamins and promotes vigorous growth. The epsom salts supplies magnesium, in soluble form, required in photosynthesis. Iron also gives deeper and richer colors, desirable in most cases, notably lavenders, purples, and pinks. Too much iron, however, does not improve bright scarlet roses and daylilies. The resultant deeper red is not nearly so bright. The Cygon protects roses and daylilies against sucking insects like aphids (deadly) and thrip. Roses are protected against rose midge. Cane borers often start to drill a rose cane protected with Cygon and quit after about 1/4 inch without laying eggs. Maybe they do not like the taste of the Cygon.

Sometimes I add a growth hormone, or a soluble seaweed to the brew. You can add your own magic components.