Liquid fertilizer immediately provides nutrients for soil. It is great for getting fast results for yards damaged by weather, foot traffic or wildlife. In order to use the fertilizer, you must attach the bottle to a garden hose. Though difficult to know where you've sprayed, walking imaginary lines back and forth across your yard will ensure an even spread. Buying liquid fertilizer for large yards requires you to figure out your square footage and the right type of fertilizer to use.
Conduct a soil pH test on your yard. Purchase a testing kit from your local gardening supply store or county extension office. Dig a hole 6 inches deep and collect soil samples for the sterile containers. Mail away the samples to the address provided and wait for the results.
Choose a fertilizer that amends the soil. If your yard's pH balance doesn't need adjusting, pick a liquid fertilizer high in nitrogen to promote growth. Most lawn-specific fertilizers will have higher nitrogen amounts. Look at the label on the fertilizer bottle for the NPK amount. NPK stands for nitrogen, phosphorus and potassium.
Measure your yard's width and length. Multiply both numbers together to obtain the square footage. You have to add the square footage of your front- and side-yard areas. Buying more liquid fertilizer than you need won't pose a problem, because the majority of liquid fertilizers need to be reapplied every 4 to 6 weeks. The label on the fertilizer will indicate how much square feet it covers.
Compare prices at gardening supply stores and online. Because liquid fertilizer is more expensive than granular fertilizer and will have to be frequently applied, it's best to shop around first to find a reasonable deal.
Wear gloves and goggles when spraying your yard. Fertilizer is harmful to the skin; therefore, refrain from fertilizing on a windy day.