The best time to fertilize your lawn in Michigan is in the late summer to fall, from early September to November, to tuck your lawn in for winter. However, if you’re starting in spring, hold off until May.
Fertilizing at these times will ensure your lawn in the Great Lakes State stays healthy and vibrant all year round.
Best time to fertilize your lawn in Michigan
Michigan’s climate is perfect for cool-season grasses because they thrive in cooler temperatures and can endure the state’s cold winters. These grasses grow vigorously in the mild weather of spring and fall, making these seasons ideal for fertilization to promote strong roots and lush green growth.
Keep reading to learn more about when to fertilize your Michigan lawn, along with useful fertilizing tips.
Late summer to fall: Best time to fertilize
| Grass type | September | November |
| Fine and tall fescues | 1 pound per 1,000 square feet in Sept. AND/OR Nov. | 1 pound per 1,000 square feet in Sept. AND/OR Nov. |
| Perennial ryegrass | 1 pound per 1,000 square feet | 1 pound per 1,000 square feet |
| Kentucky bluegrass | 1 pound per 1,000 square feet | 1 pound per 1,000 square feet |
In Michigan, the best time to fertilize is from late summer to fall, typically from early September to November. This period allows your grass to recover from the summer heat and build up essential nutrients in preparation for the colder months ahead.
Fertilizing in the fall helps your grass grow deep roots, which are crucial for surviving winter and thriving in the following spring. It also helps to thicken your lawn and crowd out pesky weeds.
Spring: Hold off until May
| Grass type | May | June |
| Fine and tall fescues | N/A | N/A |
| Perennial ryegrass | 1 pound per 1,000 square feet in May OR June | |
| Kentucky bluegrass | 1 pound per 1,000 square feet in May AND/OR June | |
While fall is the prime time for fertilizing, spring can also be beneficial if done right. Wait until May to apply fertilizer in the spring.
Applying fertilizer too early in the spring, when the ground is still thawing, can lead to rapid top growth at the expense of strong root development. By waiting until May, after the lawn starts to green up, you ensure your grass gets the nutrients it needs to flourish throughout the growing season.
For medium to high-maintenance grasses like Kentucky bluegrass and perennial ryegrass, you can fertilize in May through June.
Summer: Keep it light
| Grass type | July | August |
| Fine and tall fescues | N/A | N/A |
| Perennial ryegrass | N/A | N/A |
| Kentucky bluegrass | 0.5 – 1 pound per 1,000 square feet | 0.5 – 1 pound per 1,000 square feet |
During summer, cool-season grasses naturally slow their growth due to heat stress. For most lawns, minimal or no fertilization is needed during summer.
Instead, focus on maintaining proper watering and mowing to keep your grass healthy. If you do fertilize in summer, opt for a light application of balanced fertilizer to support steady growth without overwhelming your lawn.
A light application typically means applying ½ to 1 pound of nitrogen per 1,000 square feet of lawn per month, and it’s particularly needed only for high-maintenance grasses like certain types of Kentucky bluegrass.
Note: It is important to learn how to fertilize your lawn properly to avoid under- or over-fertilizing. Proper fertilization ensures your lawn gets the right nutrients at the right time, promoting healthy growth and minimizing environmental impact.
FAQ about when to fertilize lawns in Michigan
Is it okay to fertilize my lawn before it rains in Michigan?
Fertilizing your lawn before a light rain can be a great idea since the rain helps wash the fertilizer into the soil, making it easier for your grass to absorb the nutrients.
However, be careful if heavy rain is on the way. A downpour can cause the fertilizer to wash away, which means wasted nutrients and potential runoff into storm drains.
Should I fertilize my lawn differently if I live in northern Michigan versus southern Michigan?
Yes, you should adjust your fertilizing schedule based on where you live in Michigan. Here’s a simple guide:
- Northern Michigan: The growing season starts later and ends earlier because it’s cooler for longer. Aim to start fertilizing around mid to late May when the soil warms up.
Finish fall fertilization by early October so your lawn can absorb nutrients before the first frost. In some areas like Traverse City, frost can start as early as September, so make sure to finish fertilizing even earlier. - Southern Michigan: The growing season is a bit longer here. You can start fertilizing in early to mid-May. The fall fertilization can continue until mid to late October, giving you a bit more flexibility.
How can I tell if my lawn needs fertilizing?
Look out for signs like a pale green or yellowish color, slow growth, or thinning patches. These are all hints that your grass is hungry for nutrients.
For a more precise answer, you can do a soil test. It’s like a health check-up for your lawn, revealing exactly what nutrients are missing. You can test your soil through the Michigan State University Extension Office to determine its nutrient needs.
What is the fertilizer law in Michigan?
The Michigan Fertilizer Law restricts the use of phosphorus fertilizers on residential and commercial lawns, including athletic fields and golf courses statewide. Both homeowners and commercial applicators must follow these restrictions.
Since 2012, phosphorus in lawn fertilizers is allowed only if a soil test indicates it is necessary. This law aims to protect waterways from excessive phosphorus runoff.
Get help from a local pro
Feeling overwhelmed by the when, what, and how of fertilizing your Michigan lawn? Skip the guesswork — Lawn Love can connect you to a lawn care pro nearby who knows exactly what your grass needs to thrive. Whether you’re in the northern or southern part of Michigan, they can tailor a fertilization plan just for you.
Main Image Credit: Dwight Burdette | Wikimedia Commons | CC BY 3.0
