Scotts Southern Weed and Feed (Bonus S): Instructions and Timing

What Bonus S Actually Is (and Is Not)

Let me clear up the confusion first, because Scotts sells three things that sound almost identical and homeowners mix them up every spring. Bonus S is a combination product: a granular fertilizer carrying the herbicide atrazine. That herbicide is the whole reason it gets a different timing and tolerance story than plain lawn food.

Grass Tolerance and Timing at a Glance

This is the table I wish every homeowner saw before they bought a bag. Atrazine tolerance is everything here, and it varies a lot by species. Lead with this, then we will get into the how.

The big takeaway: St. Augustine and centipede are the two grasses Bonus S was really built for, with zoysia and carpetgrass also on the label. Anything else is off the table. Not sure which grass is yours? A quick photo diagnosis settles it in seconds, and it pulls in the weeds and conditions active in your area so the recommendation actually fits your yard.

What It Kills and What It Does Not

Bonus S kills the weeds on its label list, and that list is mostly broadleaf weeds. In my experience atrazine works best on weeds that are small and actively growing, so the label list is a ceiling, not a promise for a lawn full of mature weeds.

Weeds on the label

• Dollarweed, hop and white clover, chickweed, henbit, dandelion, oxalis, Florida betony and Florida pusley
• Burclover, buckhorn, black medic, Carolina geranium, purslane, red sorrel, sowthistle, shepherd's purse and wild mustard
• One grassy weed: rescuegrass

Weeds it struggles with

• Mature, hardened-off weeds that have already set seed
• Tough perennials and well-established sedges, which usually need a targeted product
• Crabgrass, spurge and annual bluegrass, which are not on the label list

When to Apply Scotts Bonus S by Season and Temperature

Timing is where most people go wrong, so let me be specific about the windows. The label allows two applications a year, and for severe weeds it puts the second one about two months after the first.

Early spring

The label says not to apply during winter dormancy and to wait until after the third mowing of the season. That puts the spring shot a few weeks into green-up, with the grass actively growing and the weeds still young. Mow three times first. That's the rule.

Early fall

The second window opens as the brutal summer heat breaks and cool-season winter weeds are just germinating. Knocking out henbit and chickweed at the seedling stage in fall saves you a miserable late-winter weed problem. Again you are looking for moderate temperatures, not the lingering 90s of late summer.

A heat caution

The label gives no temperature cutoff, so this one is my own caution. Atrazine on a heat-stressed Southern lawn is how I have seen turf brown out, so once daytime highs push past the upper 80s, I hold off. Summer is not Bonus S season.

How to Apply Scotts Southern Weed and Feed

Bonus S works differently from the Scotts weed and feeds most people know. Those go on a damp lawn and sit unwatered for a day. The Bonus S label says the opposite on both counts, and the bag is the law. Here is the sequence, straight from the label.

1. Wait for the third mowing

Don't apply while the lawn is dormant. The label says to wait until after the third mowing of the season, so the grass is actively growing and the weeds are up where they can be hit.

2. Apply to a dry lawn

The label says to apply only when the grass is dry. Skip the morning dew and don't run the sprinkler first. Pick a calm day with no rain forecast for the next 24 hours.

3. Spread evenly with the labeled setting

Use a Scotts broadcast spreader at 4¼ or a drop spreader at 7¼ for the 10,000 sq ft bag, which puts down 3.45 lb per 1,000 sq ft. The Florida F2 bag uses 5¼ and 11. No hand-held spreaders; the label rules them out. With a drop spreader, line the hopper arrow up with your last wheel track. With a broadcast spreader, line each pass up about 5 feet from your last wheel track.

4. Water it in right away

The label says Bonus S must be watered in immediately after you spread it. Run the sprinklers as soon as you finish, and sweep any granules off the driveway and sidewalk back onto the lawn first.

5. Then resume normal watering and mowing

Once it is watered in, go back to your normal watering and mowing. Give the product a few weeks to show results. Weeds yellow and curl before they die, so do not panic if they are still standing on day three.

Safety and Common Mistakes

A few hard-earned cautions, because Bonus S is forgiving on the right grass and unforgiving everywhere else.

• Tree and shrub roots: Atrazine can be taken up by the roots of ornamentals and trees. The label says not to use it under trees, shrubs, bedding plants, or flower and garden plants.
• Drought stress: Never apply to a lawn that is wilting or browning from drought. A stressed lawn plus a herbicide is asking for injury. Water it back to health first, then treat in good conditions.
• Wrong grass: I will say it again because it is the number one mistake. Do not put this on bermuda, bahia, or any cool-season grass. The label prohibits all of them. If you are not certain what you have, find out before you spread.
• Runoff and water: Do not apply before heavy rain, near storm drains, ponds, or wells. Atrazine and water do not mix well, which is exactly why it is regulated.
• Pets and kids: Keep people and pets off until you have watered it in and the lawn surface is dry.

What Other Guides Miss

Most articles about Bonus S stop at when to apply it. What they skip is the strategic question: weed and feed is almost always a compromise product, and understanding that compromise is what separates a good-looking lawn from a frustrated one.

Here is the thing the bag will never tell you. The ideal time to feed your grass and the ideal time to kill your weeds are usually not the same date. Your warm-season lawn wants nitrogen when it is actively growing in late spring and summer. But atrazine wants cooler temperatures and young weeds, which pushes you toward early spring and fall. By combining the two into one bag, you are forced to compromise on one of them. Most of the time you compromise on the feeding, applying nitrogen earlier or later than the grass truly wants it.

That is fine for many homeowners who want simplicity, and I am not talking anyone out of Bonus S. But if your real problem is weeds, the smarter play is often to treat weeds with the right herbicide at the right time, and feed separately on the grass's schedule. Centipede in particular is a low-nitrogen grass that resents heavy feeding, so a weed and feed can actually push it harder than it wants. This is the nuance that gets lost when a guide treats every Southern lawn the same.

The other thing guides gloss over is diagnosis. Half the lawns I have seen treated with Bonus S did not have a weed problem that atrazine solves. They had thin turf from a disease, an insect, or a mowing-height mistake, and the weeds were just moving into the bare spots. Spraying herbicide at the symptom does nothing for the cause. That is exactly why I push diagnosis first. A free photo diagnosis tells you whether you are actually fighting weeds or chasing a thinning problem that needs a completely different fix, and the premium plan goes a step further by building a personalized 12-month care plan that tells you the exact week to fertilize for your zip code and grass type, so your feeding and your weed timing finally line up instead of fighting each other.

The Bottom Line

Bonus S is a solid tool when it is matched to the right grass, the right weeds, and the right weather. Used carelessly, it browns out lawns and disappoints people. Use it deliberately and it earns its place. For a deeper dig into the two grasses it suits best, my St. Augustine grass guide and centipede grass guide walk through everything from mowing height to feeding schedules so you can fit Bonus S into a full-season plan.

Your Bonus S Action Plan

1. Confirm your grass type first. St. Augustine and centipede are the prime candidates, and zoysia and carpetgrass are on the label too. Bermuda, bahia and cool-season grasses are off the table. Not sure, get a photo diagnosis before you buy.
2. Identify your actual weed problem. Make sure weeds, not disease or insects, are why the lawn is thinning. Atrazine only fixes a weed problem.
3. Pick the right window. Spring after the third mowing of the season, or early fall as winter weeds germinate, while the grass and weeds are actively growing. I skip summer heat.
4. Read your specific label. Confirm the rate, spreader setting and the two-per-year limit, and check with your cooperative extension office on any local atrazine restrictions.
5. Apply to a dry lawn, spreading evenly at the labeled setting with a walk-behind spreader.
6. Water it in immediately, and pick a stretch with no rain in the forecast.
7. Wait a few weeks for results, then feed and water on your grass's normal schedule, and consider separating weed control from feeding next season if you want each done at its ideal time.

Do that and Bonus S will do exactly what you bought it for, without taking your lawn down with the weeds.