Summer Lawn Care Tips for Sonoma and Napa Valley Homeowners
Summer Lawn Care Tips for Sonoma and Napa Valley Homeowners
A healthy lawn doesn't happen by accident — and keeping one through a California summer takes more than just running the sprinklers and mowing every couple of weeks. Between heat stress, dry conditions, pest pressure, and the risk of burning your turf with the wrong inputs at the wrong time, summer is actually the season where lawn care decisions matter most.
At Scott Anderson Landscaping, lawn care and maintenance is core to what we do. Here's everything you need to know to keep your lawn looking its best from June through September — and what our team does to help properties across Sonoma and Napa Valley stay green all summer long.
Know Your Grass Type First
Before anything else, you need to understand what type of grass you have, because everything — watering, mowing height, fertilization timing — depends on it.
In Sonoma and Napa Valley, two broad categories of grass are common:
Cool-season grasses like tall fescue and Kentucky bluegrass grow best in spring and fall and tend to slow down or go into a degree of summer dormancy during the hottest months. These are the most common grass types on Wine Country residential properties.
Warm-season grasses like Bermuda, Zoysia, and St. Augustine actively thrive in the heat and are increasingly popular as drought-tolerant alternatives. These varieties are well-suited to California's hot, dry summers and require less water once established.
The care protocols for these two grass types during summer are meaningfully different, so identifying what you have is the essential starting point.
Mowing: Raise Your Blade
One of the most impactful and most overlooked summer lawn care adjustments is simply raising your mower blade. Cutting grass shorter in summer doesn't help it look better — it hurts it. Keeping grass slightly taller during summer months helps shade the soil, reducing water evaporation and keeping roots cooler.
For cool-season grasses like tall fescue, the target mowing height in summer is around 3 to 4 inches. Warm-season grasses like Bermuda can be maintained at 2 to 3 inches, while St. Augustine should be kept at 3 to 4 inches as well. Scalping any grass type in summer heat creates serious stress and opens the door to weed invasion and disease.
Equally important: keep your mower blades sharp. Dull blades don't cut grass — they tear it. That tearing creates ragged blade tips that turn brown, make the lawn look stressed, and increase vulnerability to pests and disease. We recommend having blades sharpened at the start of summer at minimum.
Also worth noting — don't bag your clippings. Leaving them on the lawn after mowing is a practice called grasscycling. Grass clippings are rich in nutrients and moisture, helping to naturally fertilize your lawn and acting as a light mulch that slows evaporation from the soil surface.
Watering: Deep and Infrequent
The cardinal rule of summer lawn watering is to water deeply and infrequently rather than shallowly and often. Deep watering encourages grass roots to grow down into cooler, more moisture-stable soil layers, which builds heat and drought resistance. Shallow, frequent watering does the opposite — it creates surface-dependent roots that cook in midsummer heat.
For most lawns, watering deeply once or twice a week is sufficient, targeting approximately one inch of water per week total. During heat waves, you may need to increase to three times per week. The right timing is always early morning — before the heat of the day — so that moisture reaches the root zone before evaporation takes effect. Evening watering is a second option, though it can promote fungal issues if turf stays wet overnight without adequate airflow.
Watch your lawn for signs of heat and drought stress: grass that doesn't spring back after you walk on it, blades that start to fold or curl, or a blue-gray tint to the turf are all signs it needs water. Brown patches can indicate either underwatering or overwatering depending on context — if your soil is saturated but the lawn is still browning, cut back on frequency and check for drainage issues.
Fertilizing: Timing and Grass Type Matter
Summer fertilization requires caution. The right approach depends entirely on your grass type.
For warm-season grasses like Bermuda, Zoysia, and St. Augustine, summer is actually their peak growing season, and a mid-summer feeding can boost density, color, and heat resilience. Use a fertilizer formulated specifically for summer feeding and follow the label instructions exactly — over-application in the heat is one of the fastest ways to burn a lawn.
For cool-season grasses like tall fescue, do not fertilize in summer. These grasses are under heat stress and slow-growing. Pushing them with fertilizer in midsummer risks burning the turf and accelerating decline. The right windows for cool-season grass feeding are early spring and fall. Avoid fertilizing any grass type during extreme heat events regardless of grass type — wait for temperatures to moderate before applying.
Using slow-release fertilizers when you do feed is best practice. They deliver nutrients gradually over several weeks, reducing the risk of burn and providing more consistent growth response than fast-release products.
Weed Control
Summer heat can actually help with one aspect of weed pressure — many weeds struggle in the same conditions that stress your turf. But summer also brings crabgrass, goathead, and other opportunistic warm-season weeds that fill in any thin or bare spots.
The best weed control in summer is a dense, healthy lawn — weeds have no room to establish. Keep up with mowing, watering, and any needed spot treatment as soon as weeds appear. Hand weeding or targeted herbicide application is more effective than broadcast treatment, which can stress already heat-affected turf. Always check product labels for temperature restrictions — many herbicides should not be applied when temperatures exceed 85 to 90 degrees Fahrenheit.
Watch for Pest and Disease Pressure
Summer is prime time for lawn pests. In Northern California, the most common culprits include billbugs, sod webworms, and grubs — larvae that feed on grass roots and can cause significant damage before you ever notice it above ground. Signs include irregular brown patches that don't respond to watering, or turf that lifts easily like loose carpet with no root structure holding it down.
Fungal diseases also become more prevalent in summer, particularly when lawns are watered in the evening or when irrigation is inconsistent. Brown patch and dollar spot are the most common diseases we see on Sonoma Valley properties. Improving airflow through pruning nearby vegetation, adjusting watering schedules, and applying appropriate fungicide when needed are the key responses.
Aeration: Consider It for Mid-to-Late Summer
If your lawn sees significant foot traffic or your soil tends toward compaction — as is common with the clay-heavy soils throughout much of Sonoma County — aeration can be a meaningful mid-summer intervention. Core aeration pulls small plugs of soil from the ground, opening channels for water, air, and nutrients to reach the root zone more effectively.
Aeration in early summer can help improve soil compaction and encourage root growth, preparing your lawn for the most intense summer heat. It's also excellent preparation for fall overseeding if you want to thicken up any thin areas.
Let Scott Anderson Landscaping Handle It For You
Summer lawn care is a system — mowing, watering, fertilizing, monitoring, adjusting — and when one piece is off, the rest suffers. Our maintenance team provides regular lawn care services across Sonoma and Napa Valley, calibrated to the specific grass types, soil conditions, and microclimates found throughout the region.
Whether you want a full-service maintenance program or just a seasonal consultation to get your lawn set up for success, we're here to help. Contact Scott Anderson Landscaping today and let's make sure your lawn stays green all summer long.