Late summer and early fall in Iowa and Missouri bring out a fresh wave of weeds that love to sneak into the garden. I always notice how quickly they spread if I don’t stay on top of them during this time.
From stubborn perennials to fast-growing annuals, these weeds can steal nutrients and crowd out your plants. Tackling them now keeps your garden looking neat and sets it up for a healthier season ahead.
1. Dandelion
Those sunny yellow flowers might seem cheerful, but they’re trouble in disguise. Dandelions thrive throughout Iowa and Missouri with deep taproots that make them difficult to fully remove.
Dig them out after a good rain when soil is moist, making sure to get the entire root. Their ability to spread thousands of seeds makes early removal crucial before those fluffy seed heads develop.
2. Crabgrass
Growing flat against the ground, crabgrass becomes especially problematic in late summer across both Iowa and Missouri landscapes. Its spreading habit forms unsightly patches in otherwise neat lawns.
Pull small infestations by hand after rainfall when soil is loose. For larger areas, consider using a pre-emergent herbicide next spring, as crabgrass is an annual that dies with frost but leaves behind thousands of seeds.
3. Ragweed
Not only an eyesore but a major allergy trigger for many Missouri and Iowa residents! Ragweed produces billions of pollen grains that cause those miserable late-summer sneezing fits and itchy eyes.
Remove these plants before they flower to prevent pollen release. Wearing gloves is recommended as some people develop skin irritation from handling ragweed, especially during hot days when oils are more active.
4. Bindweed
Looking deceptively like morning glory with pretty white or pink trumpet flowers, field bindweed is actually a garden nightmare across Iowa and Missouri. Its extensive root system can reach 20 feet deep, making complete removal challenging.
Consistent removal of all visible growth eventually starves the roots. Cover smaller infestations with cardboard or landscape fabric for several weeks to deprive plants of sunlight and weaken their hold.
5. Pigweed
Farmers across Missouri and Iowa battle this rapidly growing weed that can reach several feet tall in just weeks. A single pigweed plant can produce over 100,000 seeds, creating problems for years to come.
Pull young plants completely, including roots, before they set seed. Mulching garden areas helps prevent germination, while regular mowing in lawn areas keeps pigweed from establishing its dominance in your landscape.
6. Purslane
With fleshy leaves and reddish stems, purslane spreads like a mat across gardens in both Iowa and Missouri. What makes it particularly tricky is that even small fragments can root and form new plants.
Remove purslane completely and dispose of it in trash rather than compost. Interestingly, while considered a weed, purslane is actually edible and nutritious, containing more omega-3 fatty acids than many cultivated greens.
7. Chickweed
This low-growing plant with tiny white flowers becomes more noticeable in early fall throughout Iowa and Missouri gardens. Despite its delicate appearance, chickweed can quickly form dense mats that choke out desirable plants.
Hand pulling works well for small areas, making sure to get the shallow roots. Applying a thick layer of mulch in garden beds helps prevent chickweed establishment, while maintaining a healthy, thick lawn discourages it in grassy areas.
8. Foxtail
Those distinctive seed heads resembling a fox’s tail aren’t just annoying—they’re dangerous to pets across Missouri and Iowa. The barbed seeds can work their way into dogs’ ears, noses, and paws, causing painful infections.
Mow regularly to prevent seed development in lawn areas. For garden beds, hand-pulling before seeds form is effective, while established areas might require targeted herbicide application following product instructions carefully.
9. Poison Ivy
“Leaves of three, let it be” is the old saying that helps identify this troublesome plant common in both Iowa and Missouri. Direct contact causes itchy, painful rashes that can last for weeks.
Never burn poison ivy as the smoke carries the irritating oils. When removing, wear long sleeves, pants, and gloves, then wash all clothing separately afterward. Fall is actually an ideal time for removal as the plants are easier to identify by their red-tinged leaves.
10. Lambsquarters
Often overlooked until it’s suddenly towering over garden plants, lambsquarters grows rapidly in rich Missouri and Iowa soils. The dusty, pale green leaves have a distinctive mealy appearance when young.
Pull plants before they flower and set seed. Like purslane, lambsquarters is actually edible when young, with nutritional content similar to spinach. However, its prolific seeding habit makes it unwelcome in most maintained landscapes.
11. Burdock
Famous for its clingy burrs that inspired Velcro’s invention, burdock is a biennial weed found throughout Iowa and Missouri. First-year plants form large rosettes of leaves, while second-year plants produce tall stalks with purple flowers and the notorious sticky seed heads.
Dig out first-year rosettes completely, getting the deep taproot. For established plants, cut flower stalks before seeds form to prevent spreading. Wearing gloves makes handling the prickly parts much more comfortable.
12. Creeping Charlie
Also called ground ivy, this persistent weed creates a dense carpet in shady areas across Missouri and Iowa properties. Its scalloped leaves and purple flowers might look pretty, but it quickly overwhelms lawn grass and garden beds.
Hand-pulling works for small patches if you’re diligent about getting all the rooted stems. Improving lawn density by overseeding with grass suited to shady conditions helps naturally suppress Creeping Charlie’s spread.
13. Thistle
With sharp spines and purple flower heads, thistles are unwelcome visitors in Iowa and Missouri landscapes. Their deep roots and ability to spread by both seeds and underground runners make them particularly difficult to manage.
Cut flower heads before they produce seeds, then tackle the roots. Digging out the entire root system is ideal, though challenging. For larger infestations, applying herbicide to the freshly cut stems can help prevent regrowth.
14. Smartweed
Recognizable by its lance-shaped leaves and jointed stems with distinctive sheaths, smartweed flourishes in moist areas across both Missouri and Iowa. The small pink or white flowers appear in late summer, followed by numerous seeds.
Improving drainage helps discourage smartweed in lawn areas. Pull plants before they flower when possible, and maintain a thick layer of mulch in garden beds to prevent germination of new seeds.
15. Nutsedge
Often mistaken for grass, nutsedge reveals its true identity with its triangular stems and yellowish-green color that stands out in lawns across Iowa and Missouri. Underground nutlets make this weed particularly persistent and difficult to eliminate completely.
Hand-pulling often leaves nutlets behind, leading to regrowth. Improving drainage discourages nutsedge, which prefers wet conditions. For severe infestations, specially formulated herbicides may be necessary as regular weed killers have little effect.