Trees absorb far more water than any other type of plant, with a mature weeping willow pulling up to 100 gallons per day during summer months. But the answer depends on scale: among trees, willows and poplars are the heaviest drinkers; among crops, cotton and rice demand enormous volumes; and among garden plants, certain native perennials can transform a soggy yard into a functional landscape. Which plants matter most to you depends on whether you’re trying to dry out a wet area, design a rain garden, or simply understand how water moves through the plant kingdom.
How Plants Pull Water From the Ground
Plants don’t have a pump like a heart. Instead, they move water passively through a process driven by evaporation from their leaves. As water molecules escape through tiny pores called stomata, they pull the next water molecule up behind them, creating a continuous chain of tension from leaf to root. This works because water is naturally “sticky,” forming hydrogen bonds strong enough to sustain columns of liquid all the way up to tree canopies 100 meters above the ground.
The plants that absorb the most water share a few traits. They have extensive, deep root systems with fine root hairs that maximize contact with soil moisture. They have large leaf surfaces that lose water quickly to evaporation, which in turn pulls more water up from below. And many form partnerships with soil fungi that effectively extend their root network even further. For every molecule of carbon dioxide a plant absorbs to make sugar, it loses roughly 400 molecules of water to the atmosphere. Plants with high growth rates and large canopies simply cycle more water through this system.
Trees That Drink the Most
Willows are the most commonly cited water-absorbing trees, and for good reason. A mature willow can consume around 100 gallons of water per day during summer, thanks to its massive, spreading root system and dense canopy of narrow leaves. Willows naturally grow along riverbanks and in floodplains, and their roots aggressively seek out any available moisture in the surrounding soil.
Poplars and silver maples are close behind. Both develop fast-growing, wide-reaching root systems that make them effective at lowering water tables in soggy areas. Cottonwoods, a type of poplar, are particularly well suited to wet ground and can grow several feet per year in favorable conditions. River birch is another reliable choice for waterlogged sites, tolerating standing water better than most hardwoods.
If you’re planting any of these trees to manage water on your property, keep them well away from underground infrastructure. Willow, maple, and poplar roots grow rapidly toward water sources and can infiltrate septic lines, sewer pipes, and foundations. A safe guideline is to plant trees at least as far from pipes and structures as the tree’s expected mature height. A willow that will reach 50 feet tall should be planted at least 50 feet from your septic system or drain field.
Shrubs for Wet and Soggy Yards
If a full-size tree isn’t practical, several woody shrubs thrive in consistently wet soil and help pull moisture from the ground. Buttonbush is one of the best options for low-lying, waterlogged areas. It can reach 12 feet in height and width, blooms in July, and attracts pollinators. It’s a true wetland plant, comfortable in standing water that would kill most ornamental shrubs.
Other strong performers for wet ground include:
- Winterberry: thrives in moist, acidic soils, often found naturally near wetlands and ponds
- Inkberry: an evergreen holly that tolerates wet and acidic conditions
- Swamp azalea: naturally grows in bogs, swamps, and wet woodlands, producing fragrant white flowers in early summer
- Red chokeberry: adapts to both wet and dry soils, making it versatile for yards with uneven drainage
- Spicebush: flourishes in moist, shady conditions and provides bright yellow fall foliage
Rain Garden Perennials
Rain gardens are shallow depressions planted with deep-rooted perennials that capture and absorb stormwater runoff. The key to their effectiveness is the root systems of native plants, which penetrate deep into the soil and create channels for water to infiltrate rather than pool on the surface.
The best performers for the wettest zone of a rain garden, where water collects and lingers longest, include wild iris, red milkweed, turtlehead, cardinal flower, and great blue lobelia. Blue joint grass also handles the lowest, wettest areas well. These plants tolerate periodic standing water while actively pulling moisture down through the soil profile during the growing season. For the slightly drier edges of a rain garden, native grasses and sedges fill in nicely and extend the absorption zone outward.
Lawn Grasses and Water Use
Not all turf grasses are equal when it comes to water consumption. Cool-season grasses use significantly more water than warm-season species because of differences in how they photosynthesize. Cool-season grasses need their stomata nearly wide open to maintain enough energy production for growth, which means they lose water to the atmosphere at higher rates.
Kentucky bluegrass and Italian ryegrass top the charts, falling into the “very high” water use category with evapotranspiration rates above 0.39 inches per day. That translates to a need for more than 2.7 inches of water per week to stay green and healthy. Warm-season alternatives like bermudagrass and buffalograss require substantially less. If you’re looking for a lawn that soaks up standing water in a low spot, Kentucky bluegrass will drink heavily, but if you’re trying to conserve water, switching to a warm-season grass can cut irrigation needs dramatically.
Crops With the Biggest Water Footprint
At an agricultural scale, certain crops consume staggering volumes. Cotton is the thirstiest major crop, requiring 7,000 to 29,000 liters of water to produce a single kilogram, depending on climate and irrigation method. Rice follows at 3,000 to 5,000 liters per kilogram, sugarcane at 1,500 to 3,000, and soy at around 2,000. By comparison, potatoes need only about 500 liters per kilogram.
Alfalfa deserves special mention. It’s one of the dominant water consumers in arid regions of North America, particularly in river basins like the Rio Grande and Turkey’s Konya Basin. Because alfalfa is a perennial with deep roots and a long growing season, it draws water continuously. Much of it is grown as livestock feed, which makes it an indirect but massive part of meat and dairy production’s water footprint. Globally, rice, sugar, cotton, and wheat are the four largest total water consumers among irrigated crops.
One Plant to Avoid
Water hyacinth absorbs and evaporates enormous quantities of water, but it’s one of the world’s worst invasive species. Originally from the Amazon, it has spread across tropical and subtropical freshwater systems worldwide, where it doubles its coverage every seven days under favorable conditions. Dense mats of water hyacinth increase evaporation from waterways so dramatically that they disrupt local water balances and can even affect rainfall patterns. A single hectare of coverage can produce up to 450 tonnes of biomass. It displaces native species, degrades water quality, and is considered nearly impossible to eradicate. It’s listed among the top 100 global invasive species, and introducing it to any waterway is both ecologically destructive and, in many places, illegal.