The Grass Doctor

When is the most crucial times to spread out fertilizer on a lawn?

is it spring or autumn? i have heard that spreading out a fertilizer high in nitrogen is best for spring and one high in phosphorous for autumn. which is the more important feed for a lawn and why so for this? Thanks for your answers!

Public Comments

1. In the fall.
2. Nitrogen gets leached away. So use at least some nitrogen. Some phosphorous can be available to the grass in the soil.
3. I'm surprised to see your answers so far, I thought lawns were basically dormant in the winter, and didn't need any fertilizer at all then - indeed, I thought fertilizer would only force tender new growth then, when the frost can quickly kill it back off. I never fertilize in the fall, personally. Fertilizing in the spring is hardly "crucial", either, you do this optional thing only if you want your lawn to grow vigorously during spring and summer (so you have to cut it more often). Whether or not this is a sustainable system is debatable. All chemical fertilizers used continuously like this eventually degrade the soil. For that matter, the very concept of everyone having a lawn is unsustainable - there isn't enough water for everyone to have this. I hope this gives you some different insight. I realize others may differ. Fertilize your lawn when you don't like the color or vigor of its growth, in the spring (I've used 16-16-16 if needed, but not in years). Consider using organic fertilizers instead. If you're happy with your lawn the way it is, you don't have to fertilize at all.
4. April to September.What is crucial is that you apply it when the conditions are good and the grass can take up the nutrients
5. If there's one fertiliser that I add to my lawn it is an autumn specific feed that is high in Phosphorous, as you mention. Phosphorous is the element that is responsible for root growth, and the better the lawn's root network the more able it is able to withstand drought, as well as uptake nutrients required for growth. So it survives stress conditions better, as well as manages to uptake water and nutrients to develop more growth. Depending on where you live I add an autumn feed in September or October. I often don't fertilise at any other time of the year, though a summer feed will mainly encourage more leaf growth. Hope this helps. Good luck! Rob
6. Don is absolutely right. Turf grass is the single largest crop grown in the US and consumes astronomical amounts of fertilizers which are created using fossil fuels which we all know are in short supply. You only need to do something with the lawn if it is not up to whatever your aesthetic standards are. I always counsel people to widen their range of acceptable aesthetics. There is nothing wrong with a 'weed' or two.