tjslawncare,
I will give you an exerpt from my book that explains a little about fertilizers.
Please read the important note below about applying chemicals. As far as buying them for less check a local Farmers co-op. You can by it in bulk there. If you do not have a local farmers co-op, look in the yellow pages under pest control chemicals. Some companies that carry termite chemicals also carry lawn and garden chemicals. Another idea is Lesco which is a big lawn and garden chemical supplier. You can find them at Lesco.com
I would charge a flat rate for your customers. It is easier that way. Take the cost of what they would have to pay for it at Home Depot and mark it up some. Then figure your time. But just charge a flat fee. It is much better than saying okay the fertilizer cost this much and my labor yada, yada, yada.
Fertilization
Fertilizer should be applied to maintain reasonable growth and density. Knowledge of fertilizers can impress your customers as many do not have an idea of what to use, how to use, or how often to use them. Fertilization can burn or unevenly treat a lawn. This can cause yellow patches or different shades of green. Never throw fertilizer by hand.
You will be asked about fertilizers in this business. Here are some things you need to know.
Most fertilizers have 3 components- nitrogen, phosphorous, and potassium. There are 3 numbers on the bag 20-27-5 which means
20 % Nitrogen – (1st number on the bag) is primarily responsible for plant growth and color. Too much nitrogen and it could burn the grass. Too little and the grass isn’t getting nutrients to sustain good color and growth.
27 % Phosphorous – (2nd number on the bag) encourages healthy roots, shoots, and the production of flowers. Too high a level of phosphorous can encourage your lawn to produce seed heads.
5% Potassium – (3rd number on the bag) is used all year by grasses, and is involved in heat and cold tolerance, disease resistance, and other stress tolerances.
Color of grass is a good indicator of whether it needs Nitrogen. Healthy grass should have a deep green color. If it is lighter green or lime green that might mean it is under fertilized. Keep in mind not all grasses are composed of the same make up and may have a darker color than others.
Excessive succulent growth, encouraged by fast acting, high nitrogen fertilizers, can increase thatch and make the lawn more susceptible to pests. Use complete fertilizers that contain micronutrients and some elements in a slow release form.
Broadcast (also referred to as rotary) spreaders save more time. Never apply fertilizer throwing it with your hand out of the bag. It will provide an uneven application and can damage your customer’s lawn.
Understand the settings and the rates of application for your broadcast spreader. Most fertilizer manufacturers list the recommended settings on the bag for the most popular brands of spreaders.
Important
You need to call your local county extension office and find out if you need any licenses to apply fertilizers in your area. Some states may require a license if you are doing only commercial property. Other states may require a license for residential and commercial properties. If you get caught applying fertilizers without a license they can put you out of business and slap a big fine on you. Usually they will give you a warning first.
Best of luck,
Kevin