AMERICAN GARDENER

Weeds with pink flowers include 2 closely related plants that cause enough field confusion to warrant their own dedicated comparison from multiple universities, and according to Cornell University’s Weed Science program, lady’s thumb produces pink to red-purple flowers in clusters about an inch long, while Pennsylvania smartweed produces pale to bright pink or white flowers … Read more

Weeds with white flowers include one of the most consequential identification mix-ups in all of home gardening, and according to University of Maryland Extension, poison hemlock is commonly mistaken for its harmless relative Queen Anne’s lace, even though one is a genuinely deadly plant and the other is simply an unassuming roadside wildflower. Michigan State … Read more

Invasive plants in Ohio have been subject to formal state regulation since 2018, when, according to Ohio State University Extension’s BYGL program, the Ohio Department of Agriculture finalized rules following nearly 2 years of stakeholder outreach, restricting the sale, growth, and distribution of 38 species determined to cause or likely cause economic or environmental harm. … Read more

Prohibited or banned plants in California work through a rating system that’s considerably more granular than a simple yes-or-no ban, and according to the California Department of Food and Agriculture’s Encycloweedia, a noxious weed is any plant that’s been formally defined as a pest by law or regulation, with California’s own list differing significantly from … Read more

Prohibited or banned plants in Florida carry a specific legal weight that goes beyond simply being unwanted, and according to University of Florida IFAS Extension, a plant designated as a Florida Noxious Weed cannot legally be transported, imported, collected, possessed, cultivated, or sold anywhere in the state. That’s a considerably stronger restriction than the informal … Read more

Invasive trees in Michigan follow much the same pattern as the state’s invasive shrubs and vines, since nearly every species on this list arrived as a deliberate introduction, prized at the time for fast growth, ornamental value, or usefulness as a windbreak or erosion-control planting. According to the Michigan Natural Features Inventory, a field guide … Read more

Invasive plant species in Michigan share a pattern that shows up again and again once you start looking for it: most arrived as intentional introductions, whether as ornamentals, erosion control, or wildlife forage, long before anyone recognized the damage they would eventually cause. According to Michigan State University’s College of Agriculture and Natural Resources, garlic … Read more

The idea that coffee grounds make a great fertilizer for “acid-loving” plants is one of the most widely repeated pieces of gardening advice online, and according to Oregon State University Extension, it’s largely a myth. Coffee grounds test close to neutral after brewing, generally in the range of pH 6.5 to 6.8, and any pH … Read more

Plants with very large leaves push the basic rules of leaf engineering about as far as they can go, since an oversized leaf has to move enough water from root to tip to keep the whole structure from wilting under its own weight, all while surviving wind, pests, and physical damage a smaller leaf would … Read more