dew on healthy grass

There’s a subscription box for almost everything these days—flowers, clothes, wine, and, now, lawn care. The company Sunday came on the scene in April 2019 with a lineup of seasonal plant-based lawn fertilizers delivered three times a year to customers’ doorsteps. In August, it introduced two “green” herbicidal soap-based weed killers, which are alternatives to glyphosate, the active ingredient in the weed killer Roundup.

Essentially, Sunday is a lawn fertilization service mixed with a little DIY. The boxes’ contents are based on climate, satellite imagery, and a soil test, and they simplify questions such as when to fertilize your lawn and what nutrients are appropriate for summer, fall, and winter. When a box arrives, you simply hook up the bags of liquid lawn fertilizer to your hose, using the sprayer attachment provided, and apply. Then you spot-treat your weeds.

demonstration of a man using a hose with sprayer attachment to apply Sunday lawn fertilizers. Photo via Sunday

The fertilizer application process. Photo via Sunday

Another component of Sunday—one that’s free—is its blog, The Shed. Founder Coulter Lewis began his journey as a “first-time homeowner, semi-clueless about how to care for his new backyard,” while Frank Rossi, chief science officer, has advised the likes of Yankee Stadium on sustainable lawn care. On the blog, that novice-meets-scientist synergy translates to easy-to-navigate, easy-to-understand information for the lawn-care challenged. It demystifies topics like overseeding (hint, it’s a good thing) and dethatching (for which you need a special rake).

Flower caught up with Lewis for lawn care tips and to learn more about Sunday’s weed-killer alternatives to glyphosate herbicide.

FLOWER Q&A with Coulter Lewis

Name the 3 biggest lawn care mistakes people make. 

Coulter Lewis: 

1| Mowing too short: Short grass is stressed grass. Set your mower to the max height and mow more often for grass that’s healthier and thicker. 

2| Overwatering: Watering too much and watering at night can promote fungus and other lawn diseases. Watering early in the morning deeply a few days a week is much better than watering too much every day. 

3| Missing nutrient needs: Grass needs nitrogen, phosphorus, potassium, and a host of micronutrients to thrive. Sunday plans start with a soil test to identify any deficiencies so we build fertile soil.

We’re in the late summer lull. What should we do to keep our lawns healthy through the end of summer, and into fall and winter?

Midsummer heat can be a tough time lawns. Heat stress makes your lawn more susceptible to disease and can cause unsightly yellowing. To help your grass get through the hottest summer days do these three things:

1| Water deeply. Early morning is the best time.

2| Reduce traffic stress. Maybe skip the Slip’n’slide party until your lawn’s feeling better.

3| Keep the fertilizer light. Sunday’s Heat Helper supplies just enough nitrogen to assure you don’t overdo it.

Fall is a great time to build a healthy lawn for next year. When grass has the water and nutrients it needs in the fall, it invests in building deep roots to store energy through the winter. Feed your lawn when it is still green and actively growing. Fertilizing too late will result in unused nutrients that can promote fungus or other lawn diseases. Your Sunday plan will handle the timing for you.

Your products include seaweed extract, humic acid, and recycled grocery produce. What’s the science behind using these ingredients as natural lawn fertilizers?

Frank Rossi, our chief science officer, makes sure that every ingredient we use is backed by controlled turf studies. Frank is a turf science PhD who’s spent his career researching sustainable grass management and advising for places like Yankee Stadium. Seaweed, for example, has been shown to improve grass’s ability to handle both heat and drought stress. Recycled grocery produce, on the other hand, is rich in organic matter, the foundation of rich, fertile soil.

altnatives to glyphosate herbicide

Sunday’s line up of weed killers use herbicide soaps as an alternative to glyphosate. Weed Warrior is approved for organic farms, Lewis says.

Sunday just launched two weed killers that offer an alternative to glyphosate herbicide. Can you talk about the ingredients you use and how they work without being harmful to the environment?

Our Weed Warrior is approved for use on organic farms and is powered by an herbicidal soap. The special form of soap is powerful enough to quickly dissolve the waxy coating on the leaf of weeds. Without this essential barrier, the weed is typically fully shriveled up within 20 minutes. The active ingredient is not persistent and you can plant new seeds within 24 hours.

Are these weed killers safe for pollinators and birds?

We believe that lawns should be full of life, and it’s essential that our products are safe for pollinators and birds. Both Weed Warrior and Dandelion Doom are powered by herbicidal soap and iron, ingredients that are non-persistent and are not related to the compounds we’ve all read about.

A bee flies toward goldenrod abloom with bright yellow flowers in a yard that uses organic weed killer alternatives to glyphosate herbicide

Flowering annuals and perennials, such as goldenrod, welcome pollinators to your yard. Opt for a nontoxic weed killer that won’t harm them. Photo by Terri Robertson

When should you use Weed Warrior versus Dandelion Doom?

Weed Warrior is a nonselective herbicide, so it will kill any leafy surface that you spray. This is great for sidewalks, patios, and garden beds. Dandelion Doom is a selective herbicide that will kill dandelions, thistle, and other broadleaf weeds without harming your grass. It’s perfect for those pesky weeds in your lawn.

There’s a post on Sunday’s blog about adding clover to lawns. I’ve also heard about people going for sedum-based lawns, and in shaded areas, moss. How do your products work with yards that welcome clover, sedum, and/or moss. 

We’re a big fan of clover in lawns as clover supplies the nitrogen that grass is always hungry for. We also love alternates to grass as they sometimes require less water and do better in shade. That said, every alternative comes with tradeoffs. Sedum, for example, does not hold up very well to foot traffic. Our smart nutrient program is perfect for any kind of lawn and our weed control products are spot treatments, so you can target exactly where it goes.


By Terri Robertson