LAWN TIMING • NORTH DAKOTA
When to Fertilize Your Lawn in North Dakota
Fertilize your North Dakota lawn around Memorial Day and again around Labor Day. If you only feed once a year, make it the Labor Day feeding, and get it down before September 15. NDSU Extension says fertilizing past the end of September isn’t recommended, because the grass isn’t growing enough to use it.
Timing matters more than the brand on the bag. Feed too early in spring and you grow blades at the cost of roots. Feed too late in fall and most of it goes to waste.
THE RIGHT WINDOWS
North Dakota Lawn Fertilizer Calendar
| When | Feed? | Why |
|---|---|---|
| April to mid-May | No | Grass is growing roots. Early feeding pushes top growth instead. |
| Around Memorial Day | Yes | The grass is shifting to blade growth and can use it |
| Around the Fourth of July | Optional | NDSU says skip it if the lawn is drought stressed |
| Around Labor Day, before September 15 | Yes, the most important | Fall is when grass builds roots for winter |
| Late September | Too late for most lawns | NDSU says not past the end of September |
| October and November | No | Grass isn’t using it, and it can wash away or raise winter risk |
This schedule comes from NDSU’s turfgrass soil test guide, which suggests feedings around Memorial Day, the Fourth of July and Labor Day, for up to 3 pounds of nitrogen per 1,000 square feet a year. See our Bismarck yard care calendar for everything else on the schedule.
SPRING ROOT GROWTH
Why Not Fertilize in April?
That first warm weekend makes people want to feed the lawn. NDSU says to wait: “The best time to feed your lawn in spring is near Memorial Day, not earlier.”
Here’s why. NDSU explains that early spring is when grass focuses on growing roots. “If you fertilize early in spring, your lawn will skip this phase and immediately go to producing more grass blades.” Those lawns look great for a few weeks, but they burn through their energy and are more open to disease and summer heat.
In Bismarck, where the last frost usually comes around May 12 to 14, waiting for late May is easy. Use April for raking out snow mold and putting down crabgrass preventer instead.
FALL FEEDING
Why the Labor Day Feeding Matters Most
NDSU’s horticulturist calls Labor Day the most important time to feed a lawn. In NDSU’s words, “fall is when your turf focuses its energy on growing roots.” NDSU says a fall feeding will:
- “Repair any damage that occurred to the lawn over summer.”
- “Lead to a thicker turf and a stronger root system this fall.”
- “Help the turf to tolerate stresses such as drought, diseases and winter.”
- “Lead to a quicker green-up next spring.”
NDSU suggests a fertilizer with at least 25% nitrogen and some slow-release nitrogen. For fall, NDSU horticulturists suggest a product that’s about 50% slow release.
LATE-SEASON TIMING
When Is It Too Late to Fertilize?
NDSU’s answer: “Fertilizing beyond the end of September is not recommended.” In a 2023 column, an NDSU horticulturist explains why:
- The grass has to be growing to use it. Research in Minnesota and Wisconsin found “October and November applications were wasteful.”
- Cool weather shuts it down. The lawn “is less likely to be actively growing once temperatures dip below 50 degrees Fahrenheit.”
- The nitrogen can wash away. Unused fertilizer can leach into the soil or waterways.
- October feeding is risky. It can push growth when the grass should be getting ready for winter, which raises the risk of winterkill.
There’s a Bismarck-specific reason too. Late nitrogen makes gray snow mold worse under long snow cover. See snow mold and vole damage.
What if you missed Labor Day? If it’s still mid-September and the grass is growing, a feeding can still help. After that, skip it and plan on late May.
WHEN PLANS CHANGE
Timing for Special Situations
| Situation | When to fertilize |
|---|---|
| Lawn gone dormant in summer heat | Wait. UMN says fertilizer applied during drought isn’t taken up by dormant grass. Feed around Labor Day once it’s growing again. |
| Just core aerated | NDSU says aerated lawns respond well to fertilizing “immediately after aerating,” as long as it’s still before the end of September |
| New lawn from dormant seeding | UMN suggests a starter fertilizer with nitrogen and phosphate around the time of the first mowing |
| Shady areas | NDSU says shade grows slower and needs less fertilizer |
| Weeds to control too | Treat them separately. NDSU advises against weed-and-feed because feeding and weed timing don’t line up. |
| Lawn stays yellow after feeding | Likely iron, not nitrogen. Test the soil first. See why is my lawn yellow. |
If your lawn is brown in July, see brown lawn in summer: dormant or dead? before reaching for the fertilizer.
HOW MUCH NITROGEN
How Much to Put Down Each Time
NDSU recommends about 1 pound of actual nitrogen per 1,000 square feet per feeding. The first number on the bag is the percent nitrogen. With a 25% product, that’s about 4 pounds of fertilizer per 1,000 square feet.
- Spread it in two directions at right angles to avoid stripes.
- Water it in after spreading. NDSU says that makes it more effective and keeps it from washing away in a storm.
- Sweep granules off driveways and sidewalks.
- Leave your clippings on the lawn. NDSU says returning clippings helps recycle nitrogen.
For a full program, see lawn fertilization and weed control in Bismarck.
Questions
When to Fertilize FAQ
Common questions about timing, summer dormancy and fall feeding in North Dakota.
Need help timing your lawn feeding?
Call and talk it through. We can help you plan the next feeding.
When should I fertilize my lawn in North Dakota?
Around Memorial Day and around Labor Day, with an optional feeding around the Fourth of July. NDSU says the Labor Day feeding is the most important and should go down before September 15. Use about 1 pound of nitrogen per 1,000 square feet each time.
When is it too late to fertilize my lawn?
After the end of September. NDSU says fertilizing beyond the end of September is not recommended, because grass is less likely to be growing once temperatures dip below 50°F. Research found October and November feedings were wasteful, and late nitrogen can raise winter risk.
Can I fertilize my lawn in April?
It’s better to wait. NDSU says the best spring feeding is near Memorial Day, not earlier. Early spring is when grass grows roots, and early feeding makes it skip that phase and push out blades instead, leaving it weaker for summer heat and disease.
Should I fertilize a dormant lawn in summer?
No. The University of Minnesota says fertilizer applied during drought isn’t taken up by dormant grass. Wait until the lawn is growing again, and make your next feeding around Labor Day.
Do I need a winterizer fertilizer?
Not necessarily. Most winterizers contain 5% to 10% potash. One NDSU horticulturist recommends them at Labor Day, while another says the jury is still out on whether fall potassium helps up north. The nitrogen you put down around Labor Day is the part that matters most.
How many times a year should I fertilize?
Two or three times. NDSU suggests feedings around Memorial Day, the Fourth of July and Labor Day, for up to 3 pounds of nitrogen per 1,000 square feet a year. Skip the July feeding if the lawn is drought stressed. If you only feed once, do it around Labor Day.
Bismarck Landscape
Want It Done on Time?
If you’d rather have your lawn fed on NDSU’s schedule without tracking the dates, call Bismarck Landscape.
You can also see our lawn care in Bismarck, our lawn care FAQ or other contact options.