Seasonal Weed Guide

While common weeds are often ugly and unwanted, don’t be fooled—all weeds are not alike. There are grassy weeds, for example, such as barnyard grass and different varieties of foxtail. There are sedges, like yellow nutsedge. And, there also are broadleaf weeds, like dandelion, creeping Charlie, and yarrow. But no matter which weed you consider enemy number one, odds are you’re fighting a pretty sizeable army consisting of lots of different types of weeds.

So, whether you’re battling crabgrass in the spring, creeping Charlie in the summer, or chickweed in the fall, follow this seasonal weed guide and you’ll be well on your way to winning the battle against weeds.

Seasons:

Spring

Summer

Fall

Spring

’Tis the season for grassy weeds like goosegrass and broadleaf weeds like knotweed to come out, come out, from wherever they are—namely from deep in the soil. Stop weeds before they emerge and you’ll keep them from popping up. Too late for that? Kill them after they emerge and keep them from spreading around. Remember, the more you do early in the season, the fewer weeds you’ll have to contend with later.

Common Spring Grassy Weeds

• Crabgrass
• Foxtail
• Goosegrass

Common Spring Sedges

• Yellow nutsedge
• Purple nutsedge

Common Spring Broadleaf Weeds

• Broadleaf plantain
• Buckhorn plantain
• Buttercup
• Common chickweed
• Dandelion
• Deadnettle
• Dollarweed
• Garlic mustard
• Hairy bittercress
• Henbit
• Knotweed
• Oxalis
• Speedwell
• Wild garlic

How to Control Spring Weeds

1. Apply a pre-emergent weed killer. Stop the first weeds of the season by treating them with Roundup® Landscape Weed Preventer, following label directions. It stops weeds before they grow by creating a weed barrier that prevents weeds and grasses for up to 6 months. Apply it to soil around established plants in gardens and landscapes—and be sure to tackle this task early in the season. Once soil temperatures average 50-55ºF, it’s usually too late. Set a reminder on your calendar to apply weed killer soon after the last expected frost of the season.

2. Spot treat pop-up weeds. If you missed applying a pre-emergent weed killer, we’ve got you covered. Spot-treat the little buggers when they rear their ugly heads with Roundup® Ready-To-Use Weed & Grass Killer III with Sure Shot® Wand (be sure to follow the instructions on the label). Not only will you see visible results in 3 hours, but it gets weeds down to the root—something rarely accomplished by hand-weeding. Target weeds in and around vegetable gardens, flower beds, tree rings, and mulched beds, as well as driveways, walkways, and patios. Remember, weeds grow fast, so get rid of them as soon as you see them.

3. Control lawn weeds. Strong, healthy turf crowds out weeds, so spot-treat tough lawn interlopers—without hurting your lawn—with Roundup® For Lawns (click here for Northern lawns and here for Southern lawns). When used as directed, it starts working immediately and kills to the root. Be sure to treat spring lawn weeds when they’re young and growing, but for newly seeded or sodded areas, wait until after the third mowing to make your weed-killing move.

4. Love on your lawn. To help control a variety of different weeds, mow your lawn regularly and reseed bare patches. Be patient, though—you don’t want to mow until grass wakes up from its winter slumber. Once it starts growing, wait until it’s at least 3 inches tall to bring out the mower. Also, make sure you don’t cut more than one-third of length of the grass blades during any single mowing. This kind of TLC will go a long way toward reducing weeds that spread from seed (we’re talking to you, pesky dandelions!) and allowing your lawn to fill itself in with healthy turf.

Summer

Long, hot summer days make it prime time for outdoor fun – and weeds. If you let them, warm-season grassy weeds (goosegrass, anyone?) and broadleaf perennial weeds (oh, oxalis!) will come on full-force. What’s more, when conditions are hot and dry, weeds send their roots even deeper to look for water, making them harder to pull. Do your best to keep up a regular routine of lawn and landscape maintenance. Remember, an ounce of prevention equals a pound of cure.

Common Summer Grassy Weeds

• Crabgrass
• Foxtail
• Goosegrass
• Japanese stiltgrass
• Quackgrass

Common Summer Sedges 

• Yellow nutsedge
• Purple nutsedge

Common Summer Broadleaf Weeds

• Black medic
• Broadleaf plantain
• Canada thistle
• Chickweed
• Clover
• Creeping Charlie
• Dandelion
• Dollarweed
• Hedge bindweed
• Mugwort
• Oxalis
• Pigweed
• Poison ivy
• Pokeweed
• Purslane
• Wild violet

How to Control Summer Weeds

1. Target those nasty weeds. No need to treat the nice areas of your landscape when all you see are a few summer stragglers. A ready-to-use weed killer like Roundup® Ready-To-Use Weed & Grass Killer III with Sure Shot® Wand lets you target pop-up weeds quickly and easily. When used as directed, it kills all types of weeds and grasses to the root. Bonus: The Sure Shot® Wand’s protective shield fits right over the weed to keep the spray focused where you need it.

2. Mulch your beds. If you didn’t mulch in spring (or if your mulch is a little thin), add some more. It’s a great protector because it helps the soil temperature stay cooler in the dog days of summer, plus keeps moisture in and weeds out. It helps stop weed seeds from spreading, too. Spread mulch around the plants in your garden and landscape beds, and around trees and shrubs.

3. Mow and water like Goldilocks. The trick is to mow and water not too much and not too little, but just right. (Turfgrass likes that.) Mow your lawn too short and weeds like chickweed and crabgrass will take that as a sign that it’s time to take center stage. Keep it too wet, and wild violet and nutsedge starting showing up more and more. If it’s too dry, yarrow, black medic, and goosegrass start to grow. Of course, lawns grow at different rates so there is no one-size-fits-all schedule. Your goal is to care for your lawn, not stress it. Keep following the one-third rule of grass cutting. For watering, most lawns need about an inch of water a week, including rain water.

4. Treat the gaps. Different types of weeds can pop up pretty much willy-nilly, including in tiny and dry cracks and crevices, around shrubs, along walkways, in driveways, and in and around patios and pavers. Anytime you see ‘em, treat ‘em with Roundup® Ready-To-Use Weed & Grass Killer III with Sure Shot® Wand. It lets you spray continuously so you can target those in-the-gap weeds without bending over or tiring your hand. As always, read and follow the directions!

Fall

Once the heat breaks, cool-season weeds are ready to come out and play. Common chickweed, shepherd’s purse, hairy bittercress—the list goes on. Unless you stop them, autumn is their season to rise and shine.

Common Fall Grassy Weeds

• Annual bluegrass (luckily, most other grassy weeds tend to die back in the fall)

Common Fall Broadleaf Weeds

• American burnweed
• Broadleaf plantain
• Buckhorn plantain
• Burweed
• Buttercup
• Canada thistle
• Carolina geranium
• Common chickweed
• Common cocklebur
• Hairy bittercress
• Henbit
• Pearlwort
• Poison ivy
• Pokeweed
• Ragweed
• Shepherd’s purse

How to Control Fall Weeds

1. Spot-treat landscape weeds. Every weed has a lifecycle. That means the weeds you spot-treated in summer are not the same as the ones you’ll need to spot-treat in fall. Fall weeds like henbit, chickweed, and buttercup are best controlled while they’re young and actively growing, so of course you’ll want to treat them as soon as you see them. It’s important to know, too, that fall weeds that withstood the stresses of summer are especially tenacious. Use Roundup® Ready-To-Use Weed & Grass Killer III with Sure Shot® Wand to kill weeds to the root—it’s so much more effective (and easier on you!) than trying to hand-pull them.

2. Kill lawn weeds. It’s a new season and different weeds are ready for their turn at attempting a takeover. Fortunately, the same warm days and cool nights that make fall such an ideal growing time also make it an ideal time to tackle these actively growing invaders. As you’ve already heard, young, growing weeds are easier to kill, so treat them as soon as they pop up with Roundup® For Lawns (click here for Northern lawns and here for Southern lawns). It kills tough fall weeds like lawn burweed, pearlwort, and Carolina geranium, yet won’t harm your lawn when used as directed.

Pro tip: Some weeds are super ornery. You may need to hit them with a weed control product more than once if they don’t go down the first time.

3. Continue healthy lawn practices. The best defense against grassy weeds and broadleaf lawn weeds is a thick, healthy lawn. Keep feeding, watering, and mowing to help your lawn stay strong. That being said, here’s the rule of thumb for when to take a lawn care break until spring: Stop when your lawn stops growing.

Whether it’s spring, summer, or fall, timing is every when it comes to dealing with weeds. Let this guide serve as a handy reminder of the many different types you may be facing, plus (of course!) what to do to keep your lawn and landscape weed-free all year long.