The answer is as long as there is no rainfall forecast for at least 48 hours. If you live in a rainy area, never apply fertilizer unless you have at least 48 hours of non-rainy weather forecast. Rainfall or irrigation will move the fertilizer into the soil and/or potentially wash it off into storm drains. The rain could also physically move your newly applied product which may result in uneven application, exposing the plant to higher concentrations of nutrients than intended. If you are regularly applying fertilizers from a commercial company, always read any accompanying literature that comes with their products including the label and applications rates. In this case study we will be using Milorganite which requires applications to be made prior to rainfall.
Tip on how to fertilize lawn before rain
- You should also be aware of the type of soil in your yard; clay soils retain more moisture than sandy soils, so if you live in an area with clay soil, it will take longer for nitrates to leech out into the grass’ root zone. Make sure that there is no rainfall predicted for at least 48 hours after fertilizing (72 hours is even better); again, refer to your seed package for specific recommendations. Finally, keep pets off your lawn until it has been watered thoroughly, as they may suffer from nitrates toxicity.
- Aerate your lawn if you notice that it’s compacted so that water and fertilizer can penetrate deeper into the soil. To aerate a lawn with a machine, rent or hire a power aerator in your local area to do this job for you. If doing it manually, use a spike aerator with holes 1/2 inch wide and 2 inches deep in straight lines across your lawn every 12 inches.
- You fertilize, but it doesn’t rain for an extended period of time–in some cases, months! In this situation you need to make sure there is proper drainage your property.
- If the area you live in is clay soil, water immediately after fertilizing so that the nitrates can leech into the grass’ root zone before they have time to do harm.
- Watering thoroughly doesn’t mean one good sprinkling; it means several times per day until the lawn has enough moisture to cover its roots.