Slow Release vs. Fast Release Fertilizer
Everything you need to know about choosing the right fertilizer to keep your lawn green and healthy all year round.
What's the Difference?
The answer is simple — slow release fertilizers spread nutrients over an extended period of time, while fast release fertilizers dissolve quickly, making nutrients readily available almost immediately. Both types contain the same essential nutrients, but the way they are derived and delivered is fundamentally different.
Slow Release Fertilizer
Nutrients Last Longer
Slow release fertilizers make nutrients available for up to two months, giving your lawn consistent nourishment over an extended period.
Perfectly Timed Applications
Professional services use slow release fertilizers so that your first application lines up perfectly with your second, applied 4 to 6 weeks apart, keeping your lawn green all year.
Less Burn Risk
An over-application of either fertilizer can burn your lawn, but slow release fertilizers are far less likely to cause burning, putting less stress on your turf.
Fast Release Fertilizer
Lower Cost
Fast release fertilizer is cheaper to purchase, making it an attractive option for budget-conscious homeowners.
Best Used in Fall Only
The best time to use fast release fertilizer is in the fall when your lawn is preparing for winter. It quickly releases energy to the root system as the grass enters dormancy.
Short-Lived Results
Fast release fertilizers only make nutrients available for about two weeks, requiring more frequent applications to maintain lawn health.
Cons of Fast Release Fertilizer
Weakens Your Lawn
Too much top growth caused by immediately available nitrogen is harmful. The grass produces top growth while roots are still developing, making your lawn more vulnerable to disease.
More Mowing Required
Fast release fertilizer can cause the grass to grow in bursts, requiring more frequent mowing to keep the grass at a reasonable height.
Higher Burn Risk
Over-application of fast release fertilizer is more likely to burn your lawn compared to slow release, and frequent reapplication increases this risk.
A Note on Organic Materials
There are many slow release fertilizers available to buy, or you can use organic materials such as manure and compost. Keep in mind that if you use organic materials, they require more watering during extremely high temperatures, as heat can cause them to release nutrients too quickly.
The Bottom Line
Slow release fertilizers are best for most or all applications on your lawn. An extended release of nutrients puts less stress on your lawn and will create a stronger, healthier turf. Save fast release fertilizer for fall preparation only, and always avoid over-application of either type.
