The small piece of turf that I maintain in my garden is a lovely shade of emerald green right now, as are the lawns of most homeowners. The fact that our turf in this part of the world is composed of cool season grasses means that your lawn is going to look great in April and May.
Without a bit of effort on your part, however, the lawn won’t look this green for much longer. Lawns will survive without fertilizer, but you have to decide whether you want a lush, thick carpet of turf, or a straggly, thin lawn filled with weeds and troubled by diseases.
You could survey your local garden centres, hardware and home improvement stores right now and find perhaps a couple of dozen or more different types of lawn fertilizers, all with different numbers on the bag, all promising terrific results. Sometimes choice is good, but it can also be very confusing.
The three numbers on the bag tell us the relative amounts of three main elements in the fertilizer, nitrogen, phosphorus and potassium. A fertilizer that contains all three is known as a balanced fertilizer. This is actually a misnomer, because the amounts aren’t balanced at all. Lawns need more nitrogen than anything else; it’s what makes the turf green after all. Phosphorus isn’t really needed unless you know your soil is deficient. Potassium helps with disease resistance and winter hardiness.
A good lawn fertilizer will contain the three main elements in a ratio like 6-1-4, with more nitrogen, little phosphorus and more potassium. Cheaper fertilizers will have cheaper sources of nitrogen. There are two forms. One is water soluble, which releases quickly and provides a quick greening effect. If you like to fertilize frequently, and enjoy pushing your mower around on a very regular basis this is the type of nitrogen for you. It will leach out of the soil with irrigation, and you’ll have to re-apply it more often, but it will certainly make your lawn green while it lasts.
The second form is known as slow-release. The nitrogen is coated to allow it to break down more slowly. Turf growth is more even, and the effect of the fertilizer lasts longer. Sulfur was initially used as a coating, but you will find better fertilizers with a polymer coating that lasts even longer.
The best fertilizers have a 50/50 mix of quick and slow release nitrogen, to make the lawn turn green right away, and then maintain the colour for several weeks after the application. These fertilizers will also contain sulfur and iron in small amounts; both help to keep the turf green.
You’ll find pricing on lawn fertilizers ranging from under $10 to over $30. Read the label, see what type of nitrogen is used, and check the coverage to determine what the best value is. You get what you pay for in most instances.