As a general rule we fertilize 3 to 4 times a year (Easter, Memorial Day, Labor Day, and Halloween). If you choose to fertilize once, do it in the fall. If you chose to fertilize twice, do it in the fall and spring.
Use a fertilizer that is blended for our Colorado soils like our ScienTurfic 20-20-10 with iron and sulfur.
They refer to the percentages of nitrogen, phosphorus, and potassium.
Nitrogen – growth, color, density and chlorophyll Phosphorus – growth of new roots and rhizomes along with plant vigor Potassium – Plant health, stress resistance, and cold hardiness
Iron. It is involved in chlorophyll production. A lawn that is deficient in iron turns yellow.
ScienTurfic Sod recommends a cyclone or rotary spreader. It will apply the granules more evenly, which avoids dark green and yellow strips that often happen with a drop spreader.
If the fertilizer contains iron, the pellets when wet will stain sidewalks, curb, gutters, and swimming pools.
Application rates are determined by multiplying the first number, which represents the percentage of nitrogen contained, times the weight of the bag.
Using the ScienTurfic fertilizer, which has a formula of 20-20-10-2fe-3s, multiply the first number (20%) by the weight of the bag (20 lbs) which will equal 4 (lbs of nitrogen). If you want to apply 1 lb of nitrogen per 1000 square feet this bag will cover 4,000 square feet.
Not always. Let’s compare a 20 lb bag with the numbers of 20-20-10-2fe-3s and a 40 lb bag with the numbers of 10-5-5, both covering 4,000 square feet. Remember the total of the numbers represent the percentage of total nutrients in the bag.
The 40 lb bag will contain 20% nutrients with the rest being filler, while the 20 lb bag will contain 55%. 20% of 40 lbs will equal 8 lbs of nutrients compared to 55% of 20 lbs which will equal 11 lbs. Obviously in this case the 20 lb bag is the best deal, if both were the same price.
In this example, it is the percentages of the 3 elements. Dividing these numbers by 10 leaves a 2:2:1 ratio.
The goal should be to produce reasonable amount of top growth but not at the expense of root growth and carbohydrate storage.