The 411 on Fertilizer

Not sure what type of fertilizer to use? Confused by all the numbers on the fertilizer bag? We’re here to answer all of your questions about fertilizer to help keep your yard looking beautiful well after it’s planted.

What do the numbers on the fertilizer bag mean?

On all bags of fertilizer there is a label with three numbers. These numbers represent the percentages (by weight) of three key nutrients: nitrogen, phosphorus and potassium. Nitrogen benefits the green, leafy growth of your plants. Phosphorus assists in strong root and stem growth, as well as bloom production. Potassium regulates the CO2 uptake and the general health of your plants. Choose a fertilizer that has the right mixture of these three nutrients for your needs.


Which fertilizer should I use?

Generally, there are two types of lawn fertilizer:

  • Starter fertilizers. These fertilizers are high in phosphorus to promote growth under the soil.  Starter fertilizer should be used when seeding a new lawn and after the new strands of grass have begun to grow. Starter fertilizer is not recommended for use on established lawns. These types of fertilizers will have numbers like 24-25-4.
  • Fertilizers for established lawns. These types of fertilizer have a high nitrogen content to promote above-soil growth and health. They will contain little if any phosphorus or potassium. Such fertilizers will have numbers like 46-0-0 or 23-3-5.


When should I apply fertilizer on an established lawn?

Determining how and when you should fertilize depends on when your lawn was installed. At a minimum, established lawns should be fertilized in September and late fall. Be sure to follow the application instructions on the label of the fertilizer bag. You will need to know how many square feet your lawn is to use the correct amount.