Welcome to the dog days of summer. With excessive heat and humidity, and perhaps lack of rainfall, your lawn may be stressed or even dormant at this point. This post is to help your cool season lawn survive and thrive throughout the month of July.
Keeping your lawn irrigated is the most important factor in keeping your turf healthy surviving these next several hot, humid and sunny weeks ahead of July. In a perfect world there would be 1-2″ of fresh rainfall every 7-10 days. But especially here in the Northeast, you can never rely on mother nature.
Aim for a minimum of 1 inch to 1.5 inches of water every 7-10 day. Get yourself an impact sprinkler and an irrigation timer and water deeply but infrequently. Meaning, water longer (~0.5 in. of water) every couple of days – versus a little amount of water (~0.25 in. of water) everyday.
Water early mornings. Don’t try to water deeply in the middle of the day as a lot of your water is going to evaporate and not soak deeply into the soil. Also avoid watering late at night. When too much water is left on the grass for an extended period of time, diseases are more like to occur. More on fungus below.
You can run your irrigation on hot spots of your lawn during the day, for roughly 7-10 minutes to cool the grass and soil. Example: I have full sun on my side yard and I will run two zones (10 total irrigation heads) for eight minutes each shortly after lunchtime.
Note, always obey your town’s local watering restrictions.
If your lawn is drought stressed or dormant in July, do not mow your lawn. Since the grass is under stress and not growing, there’s no need to add more by mowing unnecessarily. Let it be and it will come back with water and cooler temps.
If your lawn is lush and green – great job! Your grass is certainly slowing down and there’s probably no need to mow three or more times per week like you were in May. Adjust your mower deck height and cut your grass at a taller length. The longer blades will help shade the crowns and soil from the sun and prevent burning.
And as always, mow with sharp blades and a clean deck.
Add the outside temperate (in farenheit degrees) and outside humidity (the percentage). And if that number hits 150 or above, you’re in the danger zone for lawn fungus and diseases. This is a very common number in July. If you’ve been following my cool season lawn care guide you should have applied a few applications of fungicide prevention by now.
Liquid is definitely your best fungicide option. Propiconazole 14.3 at 2 ounces per 1,000 sq. ft. will provide you with a curative rate. Do not apply this more than three times in a row. Fungus and diseases can become resistant to a chemical (fungicide) if applied too frequently. So be sure to mix this up. After your second or third application of Propiconazole, apply one application of Azoxystrobin. It’s more expensive than Propiconazole but a pint will cover at least 20,000 sq. ft. at a curative rate (0.77 oz per 1,000) – and nearly an acre at a preventative rate (0.38 oz per 1,000). Scott’s DiseasEx also contains Azoxystrobin as its main active ingredient, but this is a granular product that you also have to water in.
To prevent fungus, apply these chemicals at the preventative rates and application times (14-21 days) as instructed on the labels.
If fungus is present, mow with a sharp blade, a clean mower deck and bag your clippings. You want to ensure that there’s enough airflow in the turf to help circulate and dry out any moisture.
If your lawn is drought stressed or dormant, you should be applying nothing but water to your lawn. Your last fertilization in June should be enough food for your lawn to store and use through July and throughout the summer as needed.
Even if your lawn is thriving, you should at least dial back the total nitrogen to less than 0.5 lbs. of N of organic, slow release (non-burning) per 1,000 like Milorganite or a Milorganite alternative. Use our free nitrogen calculator or lawn fertilizer calculator to help ensure that you’re not over applying. You should not be forcing growth in this heat and humidity. Even if the turf looks vibrant and green, it naturally wants to slow down its top growth.
Bottom line: skip fertilizer this month.
Things like humic acid and sea kelp can really help your soil, particularly when watering in scarce. Below are some safe and effective micronutrients for you to spoon feed this July assuming your lawn is not under too much stress.
- Molasses Powder: Will help break down excessive thatch in your turf and provide some energy to activate soil microbes in the form of sugars/carbohydrates. Product: Kelp4Less
- Calcium: Will help your lawn under drought and stressful conditions such as the summer heat. Product: Jonathan Green Magical Plus
- Humic Acid & Sea Kelp: Helps the lawn better manage heat, drought, disease, insects and other stresses. Stimulates soil micro-organisms to promote humus in the soil. Products: ExtremeBlend or Super Lawn Solutions.
If you have not yet applied, this needs to be applied and watered in immediately (before July 4th). Time is really ticking and you should consider some grub killer to have on hand in case. Look for products that contain ingredients like Carbaryl (Sevin) or Trichlorfon (Dylox).
Grub are the main culprits when it comes to summertime insect damage.
July Lawn Care Summary
- High heat and low rainfalls may lead to dormant grasses
- Irrigate as long as your town allows. Aiming for 1″ – 1.5″ ofwater every 7-10 days
- Keep an eye out for lawn diseases and fungus – especially as humidity rises
- Watch for grubs and other lawn insects
- Fertilize with low-nitrogen organics or skip all together
- Never fertilize or mow stressed or dormant turf