Fertilizer is an important ingredient in your lawn care plans. You can by commercial blends, or make your own as long as you understand what makes a good fertilizer for grass. Well-fed grass is healthy, disease resistant and easy to care for. Fertilizer improves the soil so plants can grow.
Organic or Commercial
Making your own lawn fertilizer has many benefits. It is cheaper, cleaner, reduces your garbage waste, and you'll feel good about it too. Many people make their own fertilizer for the garden, then go out, and buy bagged fertilizer for their grass. If you do not have the room for compost, or the time to create your own fertilizer there are plenty of excellent commercial choices for grass fertilizer.
Nitrogen
Make your fertilizer for the grass high in nitrogen. Grass thrives on high levels of nitrogen that you find in plant materials. Save clippings from your lawn when you mow and add them to your compost. Include leaves in the fall. Sawdust and wood chips from any home project or tree trimming are excellent sources of nitrogen. Get additional sawdust from a local mill for a low cost nitrogen addition. Animal manure is a very popular nitrogen based compost addition. There are drawbacks to manure. Animal feces often contain weed seeds from their ingestion of grasses and weeds. The manure from some animals is "hot" and must be aged before you spread it to avoid burning the grass and plants.
Potassium
The potassium in grass fertilizer helps resist disease. Add organic materials including banana peels and fish to increase potassium levels. Wood ashes from your fireplace produce an excellent supply of potassium for a compost pile. Potassium is salt based and cannot be used on plant material alone without burning it. Use caution when applying any fertilizer, commercial or home produced, aged or raw, and always wear protective clothing.
Phosphorus
The final ingredient in grass fertilizer is phosphorous. Animal manure delivers enough phosphorous to the compost. The phosphorous levels of the compost are the main reason compost needs aging to keep it from being too strong. Raw manure, even at the right levels of 10-10-10 (nitrogen, potassium, and phosphorous) still produce too much heat for plant matter without aging to cool it down.
Organisms
Add earthworms to help spread your manure to greater levels. The worms eat plant matter and burrow deep into the ground around the roots of plants. As they go their excretions deliver the nutrients right to the grass roots where they'll do the most good. In their own way, earthworms are organic fertilizer machines on the move.
Cautions
Use care when spreading any form of fertilizer. Wear long-sleeved shirts and pants, and gloves to cover skin. Wear dust masks and goggles to protect lungs and eyes.