What 8 Common Weeds Say About Your Soil—From pH Levels to Nutrient Deficiencies These weeds can tell you important things about your soil. Close Credit: Olena Malik / Getty Images Your garden is home to a carefully chosen selection of plants you nurture and cherish. But like it or not, it is also home to plants you didn't plan for: weeds. While these uninvited garden inhabitants can provide benefits, they can also compete for nutrients and water, starving desirable plants of the essential resources they need to thrive. One upside? Weeds can provide important clues about the quality of your garden soil, such as its pH level. "Why do we care about pH levels? Because they affect nutrient absorption," says garden coach Jennifer Holston. "For example, iron absorbs best under acidic conditions and calcium absorbs best under alkaline conditions." Ahead, our experts explore a variety of common garden weeds and explain what they reveal about your soil. Teri Speight, landscape gardener, garden coach, podcast host, and co-author of The Urban Garden Jennifer Holston, garden coach and home hydroponics specialist 15 Invasive Weeds That Are So Pretty, You Might Mistake Them for Flowers 01 of 08 Broadleaf Plantain Credit: anmbph/Getty Images Soil May Be Well-Drained and FertileEarly settlers brought broadleaf plantain (Plantago major) from Europe to North America, as it was valued at that time for its various medicinal uses. Today, broadleaf plantain is considered a weed that spreads prolifically, with some plants able to produce 20,000 seeds. If it's present in your yard, your soil is likely well-drained and fertile. "The nutrients are well balanced, providing sufficient nutrients for healthy soil," says landscape gardener and author Teri Speight. She adds that this is also true for blackseed plantain (Plantago rugelii), which is in the same family as broadleaf plantain. 02 of 08 Dandelion: Credit: Bernard Lynch / Getty Images Soil May Be Compacted, Dry, and Low in Nutrients Loose dandelions (Taraxacum) might feel like an eyesore if your goal is a picture-perfect lawn. But if you're fine with these yellow flowers growing on your property, you might find that dandelions have something to offer. "I love dandelions. They earned a weedy classification due to their prolific nature, but they’re amazing," says Holston. "The deep taproots of dandelions break up compacted soils and deliver calcium and other nutrients to the surface," she says. She explains that dandelions often appear if the soil is compacted, has low nutrients, or is dry. 13 Ways to Eat Dandelions, From the Roots and Greens to the Flowers 03 of 08 Stinging Nettle Credit: Judith Haeusler/Getty Images Soil May Be Acidic and Calcium DeficientStinging nettle (Urtica dioica) can irritate the skin, but some gardeners don't mind its presence and even harvest it for eating. That said, stinging nettle in your garden may mean your soil is lacking. "A common weed that shows a calcium deficiency in the soil is stinging nettle," says Speight, adding that it also tends to grow in acidic soils. 04 of 08 Crabgrass Credit: Yesim Sahin / GETTY IMAGES Soil May Be Nitrogen Deficient There's a good chance you'll see crabgrass (Digitaria sanguinalis) if your soil lacks nitrogen. "Crabgrass, ragweed, plantain, mullein, sheep sorrel, and moss all thrive in a nitrogen-deficient ground," says Holston. While it isn't ideal from an aesthetic perspective, Holston notes that crabgrass can help the soil. "In areas (such as construction sites) where disturbed soil sits barren, and rainfall washes away nutrients, you’ll notice crabgrass. This knight of the weed world latches its roots to the barren dirt and holds on, stopping erosion and further nutrient depletion. Crabgrass is part of nature’s arsenal to heal the ground we grow on," she says. 05 of 08 Lambsquarters Credit: Orest Lyzhechka/Getty Images Soil May Be Phosphorus Deficient Also known as white goosefoot, lambsquarters (Chenopodium album) generally pops up in good-quality soil, but is known to grow in phosphorus-deficient soils. Knapweed (Centaurea) is another plant that grows well when phosphorus is low, so if you see both weeds, you might want to do a soil test to check your phosphorus levels. 06 of 08 Chickweed Credit: Getty Images Soil May Be Dense and Nutrient-DeficientChickweed (Stellaria media) is a common weed that grows across most of the United States. Speight explains that the presence of chickweed may indicate dense, nutrient-deficient soil. "Amending the soil with compost or lime, in addition to aeration, can correct this soil diagnosis," she says. "I suggest obtaining a soil test to ensure accurate correction of these soil conditions." Chickweed is sometimes utilized as a spinach-like green in salads. 07 of 08 White Clover Credit: Catherine McQueen/Getty Images Soil May Be Nitrogen Deficient White clover (Trifolium repens) grows prolifically in lawns and gardens. While it is a nuisance to some, many let clover grow as a beautiful alternative to manicured turf grass. Clover is a legume, and like others in this plant family, it's a nitrogen fixer, meaning it incorporates nitrogen back into the soil. If you have white clover growing, it may mean your soil is nitrogen deficient, so it's beneficial to let it grow. 08 of 08 Thistle Credit: Natka-i / Getty Images Soil May Be Poor, Dry, CompactedNobody likes getting poked by the thistle (Cirsium) living in their garden bed or lawn. When this spiky weed blossoms, it produces seeds that spread it throughout the landscape, making its presence even worse. Thistle typically signals that the soil is poor, dry, and compacted, so you may need to amend your soil to get rid of this plant once and for all. Explore more: Garden