A clover is a small plant in the pea family, best known for leaves split into three leaflets. Its real significance is underground, where it works with soil bacteria to feed itself, and the soil around it, from the air.1University of Arkansas System Division of Agriculture. Value of Nitrogen Fixation From Clovers and Other Legumes The same plant many people pull from lawns as a weed is grown on purpose by farmers as a free source of fertilizer and animal feed. The benefits come with a few real catches for grazing animals and for native grasslands, depending on which kind of clover is involved.
How to Recognize a True Clover
All true clovers belong to one plant group, the genus Trifolium, a name meaning three leaves.2Competitive Lawn. Identifying Clover and Clover Look-Alikes in Your Lawn The common lawn clover, white clover, has three rounded or oval leaflets to each leaf.3Competitive Lawn. Identifying Clover and Clover Look-Alikes in Your Lawn Each leaflet often carries a pale, whitish crescent or watermark, one of the most reliable ways to identify it.4Competitive Lawn. Identifying Clover and Clover Look-Alikes in Your Lawn
The flowers help too. They grow as a dense, rounded head of many tiny florets, white in white clover and dark pink with a paler base in red clover.5PubMed Central. Edible Flowers Used in Some Countries of the Mediterranean Basin: An Ethnobotanical Overview White clover also spreads by creeping stems that root where they touch the ground, letting a single plant form a mat.6NSW Department of Primary Industries. Trophy white clover – a new cultivar for dryland pastures
Plants in the genus Oxalis, often called wood sorrel, are frequently mistaken for clover because they also have three leaflets.7MyGardenLife. Difference Between Shamrock, Clover, and Oxalis Plants Oxalis leaflets are heart-shaped or triangular rather than round.8MyGardenLife. Difference Between Shamrock, Clover, and Oxalis Plants
A quick check in your yard: look at one leaflet. Round or oval points to clover or a close relative, while a notched heart means oxalis. Oxalis leaflets often fold down like a closed umbrella in strong sun or at night, and it usually has yellow five-petaled flowers instead of clover’s fluffy round heads.
Clover leaves don’t look identical everywhere. Leaflet size varies by variety, from tiny lawn types to large pasture types, and crowded or mown clover tends to grow smaller leaves than clover left alone. Not every white clover shows the crescent, so check several leaves before deciding.
Bur clover and black medic, which are close to clover, can look much like it in a lawn, though black medic has small yellow flower clusters rather than white or pink heads. If a plant has round leaflets but you’re unsure, wait for it to flower, because the flower head is usually the clearest sign of which plant you have.
The Main Types of Clover
White clover is a low, creeping perennial that spreads by runners and is the clover most often found in lawns.9NSW Department of Primary Industries. Trophy white clover – a new cultivar for dryland pastures It survives dry spells mainly by keeping its runners alive, since new seedlings are slow to grow back to full size.10NSW Department of Primary Industries. Trophy white clover – a new cultivar for dryland pastures Red clover grows taller and is prized as a high-protein feed for cattle and sheep.11European Journal of Agronomy. Improved persistence of red clover (Trifolium pratense L.) increases the protein supplied by red clover/grass swards grown over four harvest years It tends to thin out after a few years, especially where animals graze it.12European Journal of Agronomy. Improved persistence of red clover (Trifolium pratense L.) increases the protein supplied by red clover/grass swards grown over four harvest years
Crimson clover is an annual often grown over winter as a cover crop to protect and feed farm soil.13Agronomy Journal. Cover crop biomass production across establishment methods in mid‐Atlantic corn Subterranean clover pushes its developing seed heads down into the soil, which gives it its name.14USDA Natural Resources Conservation Service. Plant Guide for Subterranean Clover
You can tell the three apart on sight. White clover hugs the ground with small white heads on single stalks. Red clover stands taller, with pinkish-purple round heads and leafy flower stems. Crimson clover has striking elongated, deep red flower spikes. Lawn clover is almost always white clover.
Each suits a different job. White clover fits lawns and paths because it tolerates mowing and foot traffic. Red clover suits hay, pasture and wildflower plantings. Crimson clover suits winter cover in vegetable beds that are replanted in spring.
Life span matters for what you plant. A perennial like white clover lives for years and keeps spreading from its runners, so one planting can last in a lawn. An annual like crimson clover completes its life in one season and returns only if it drops seed or is sown again.
How Clover Fertilizes the Soil
Plants need nitrogen to grow, and air is mostly nitrogen, but most plants cannot use it in that form. Clover gets around this by forming small swellings on its roots, called nodules, that house soil bacteria.15PubMed Central. Expression and Variation of the Genes Involved in Rhizobium Nodulation in Red Clover Inside the nodules the bacteria convert air nitrogen into a usable form.16PubMed Central. Expression and Variation of the Genes Involved in Rhizobium Nodulation in Red Clover Clover and its bacteria can supply large amounts of nitrogen without bagged fertilizer.17University of Arkansas System Division of Agriculture. Value of Nitrogen Fixation From Clovers and Other Legumes
Grass growing alongside white clover had 17 to 27 percent more nitrogen in its leaves.18Sustainability. Dwarf White Clover Supports Pollinators, Augments Nitrogen in Clover–Turfgrass Lawns, and Suppresses Root-Feeding Grubs in Monoculture but Not in Mixed Swards So clover mixed into grass can let you cut back on fertilizer. The nitrogen gets to neighbors as clover roots, leaves and clippings break down. Leaving mown clippings on the lawn returns some of it to the soil, and cover crops are turned under so the next crop can use what they stored.
To check whether your clover is fixing nitrogen, gently dig up a plant and rinse the roots. Look for small bead-like bumps. Nodules that are pink or red inside are actively working, while white or green nodules, or none at all, can be one sign the right bacteria are missing.
That missing-bacteria problem is why a new planting may need them added. The bacteria live in the soil, but a field or lawn with none of the right strain will grow clover that cannot fix nitrogen well. Clover seed is often sold coated with the bacteria, or with a separate powder called an inoculant that you mix into the seed before sowing. A yard that has grown clover before has probably built up the bacteria already, so inoculating matters most on brand-new ground.
Clover in Lawns and Gardens
Mixing white clover into grass can reduce fertilizer use while keeping a uniform, dark green lawn.19DigitalCommons@USU. Reducing Inputs and Adding Value to Turfgrass Systems Through Clover Inclusion and Plant Growth-Promoting Rhizobacteria Applications Adding clover can also reduce water and pesticide use in lawns.20DigitalCommons@USU. Reducing Inputs and Adding Value to Turfgrass Systems Through Clover Inclusion and Plant Growth-Promoting Rhizobacteria Applications Small-leafed white clover, sold as microclover, holds water better in drought and recovers faster afterwards than larger-leafed types.21Agronomy. Comparative Study on the Morpho-Physiological Responses of White Clover Cultivars with Different Leaf Types to Water Deficiency22Scientia Horticulturae. Drought stress tolerance of red and white clover-comparative analysis of some chaperonins and dehydrins
To add clover to an existing lawn, overseed in spring or early fall when soil is moist. Rake lightly so seed touches soil, then keep it damp until it sprouts. Hold off on weedkillers labelled for broadleaf weeds, since they kill clover. Expect it to fill in over a season as runners spread.
In beds, a thick clover cover shades the soil, keeping out light that many weed seeds need to sprout.23Chelsea Green Publishing. Weed Suppression: Choosing Cover Crops & Living Mulches It also competes with weeds for water and nutrients.24Chelsea Green Publishing. Weed Suppression: Choosing Cover Crops & Living Mulches Red clover dug into soil released compounds that held back weed seedlings as it decayed.25Chelsea Green Publishing. Weed Suppression: Choosing Cover Crops & Living Mulches Clover isn’t best everywhere, though: ryegrass alone held a slope together better than ryegrass mixed with red clover in its early growth.26BOKU University. The effect of root architecture on soil stability during a landslide simulation
A few drawbacks are worth weighing first. Flowers attract bees, which matters in play areas or for anyone allergic to stings. Clover can stain clothes and feel slick when wet, and it wears less well than grass on heavily used sports areas. Mowing high lets it flower, while mowing before bloom reduces bee visits.
A lawn of clover alone stays green and low, but it tolerates foot traffic less well than grass, so it suits quiet areas. In colder regions clover goes dormant and browns after hard frost, so a pure clover lawn will look bare in winter while a mix hides this better.
Clover and Pollinators
Clover flowers are mostly visited by bumblebees.27PubMed Central. Edible Flowers Used in Some Countries of the Mediterranean Basin: An Ethnobotanical Overview White clover in lawns is valued for providing food for pollinators.28DigitalCommons@USU. Reducing Inputs and Adding Value to Turfgrass Systems Through Clover Inclusion and Plant Growth-Promoting Rhizobacteria Applications29Sustainability. Dwarf White Clover Supports Pollinators, Augments Nitrogen in Clover–Turfgrass Lawns, and Suppresses Root-Feeding Grubs in Monoculture but Not in Mixed Swards Red clover varieties differed fiftyfold in how many pollinators they attracted, because varieties with more flower heads drew more insects and more kinds of insects.30Agricultural and Forest Entomology. Improving pollen and nectar supply by identifying the red clover (Trifolium pratense) cultivars that attract most pollinators
You can get more from your clover by letting some flower before mowing, or by mowing in alternating strips. Avoid insecticides on flowering clover. Mixing white and red clover lengthens the bloom season, and clover helps fill the gap between spring and summer flowers.
When Clover Causes Problems
Cattle grazing lush clover can develop bloat, a dangerous buildup of stable froth in the stomach.31Animal Feed Science and Technology. Frothy bloat in ruminants: Cause, occurrence, and mitigation strategies Soluble protein in the fresh leaves and fast digestion encourage the froth.32Animal Feed Science and Technology. Frothy bloat in ruminants: Cause, occurrence, and mitigation strategies Bloat was worse after afternoon grazing than morning grazing.33Canadian Journal of Animal Science. COMPARISON OF THREE BLOAT-PREVENTING COMPOUNDS FOR CATTLE GRAZING CLOVER Anti-foaming products given to cattle can prevent and treat it.34Animal Feed Science and Technology. Frothy bloat in ruminants: Cause, occurrence, and mitigation strategies35Canadian Journal of Animal Science. COMPARISON OF THREE BLOAT-PREVENTING COMPOUNDS FOR CATTLE GRAZING CLOVER
Sheep and goats can also bloat on rich legumes, so the caution isn’t limited to cattle. Risk is higher when clover makes up most of the pasture, which is why a grass and clover mix is the usual safeguard.
For livestock owners, introduce animals to lush clover pasture gradually and avoid turning hungry animals onto wet, young clover. Watch for a swollen left side and call a vet promptly.
Red clover is rich in isoflavones, plant compounds that act like weak estrogens, at about 20 to 40 times the level of white clover.36PubMed Central. Effect of Diets Containing Phytoestrogen on Livestock Production: Nutrient Utilization, Carcass Traits, Lactational Performance, and Reproductive Function—A Review Long grazing on highly estrogenic subterranean clover pastures caused severe, often permanent infertility in ewes.37PubMed Central. Effect of Diets Containing Phytoestrogen on Livestock Production: Nutrient Utilization, Carcass Traits, Lactational Performance, and Reproductive Function—A Review Yet ewes fed high-isoflavone red clover feed in one trial still carried as many lambs as other ewes.38animal. Fertility and growth of nulliparous ewes after feeding red clover silage with high phyto-oestrogen concentrations
Yellow and white sweet clover are close relatives that invaded mountain grasslands, favoring non-native plants over native ones.39Annals of the Association of American Geographers. Invasion by Sweet Clover (Melilotus) in Montane Grasslands, Rocky Mountain National Park They spread beyond mapped boundaries in two seasons, even into undisturbed meadows.40Annals of the Association of American Geographers. Invasion by Sweet Clover (Melilotus) in Montane Grasslands, Rocky Mountain National Park Their effect depends on the plant community; in poor soil, the added nitrogen fed other weeds.41Biological Invasions. Nitrogen-limitation and invasive sweetclover impacts vary between two Great Plains plant communities
Sweet clover is easy to tell from lawn clover. It grows tall, often waist high or more, and its flowers form long narrow spikes, not round heads. Gardeners near natural areas should not plant it.
Can You Eat Clover
Clover flowers are used in salads, cakes, fritters, soups and tea.42PubMed Central. Edible Flowers Used in Some Countries of the Mediterranean Basin: An Ethnobotanical Overview Dried clover is rich in protein, calcium, magnesium, iron and selenium.43PubMed. Elemental analysis and nutritional value of edible Trifolium (clover) species Red clover is a good clover to eat, being rich in nutrients and low in toxic metals.44PubMed. Elemental analysis and nutritional value of edible Trifolium (clover) species The flowers contain antioxidant plant compounds,45PubMed Central. Edible Flowers Used in Some Countries of the Mediterranean Basin: An Ethnobotanical Overview and red clover is a traditional remedy for coughs, stomach complaints and menopause symptoms.46PubMed Central. Edible Flowers Used in Some Countries of the Mediterranean Basin: An Ethnobotanical Overview Its plant estrogens are a reason to talk to a doctor before using it regularly, especially if pregnant or on hormone treatment.
Pick only where no weedkiller, fertilizer or dog traffic has reached, and avoid roadsides, where plants pick up pollution. Confirm it is true clover, not oxalis or sweet clover. Start with small amounts, since raw clover can be hard to digest.
Flower heads can be pulled apart and the petals sprinkled fresh onto salads for a mild, slightly sweet taste. Dried flower heads steeped in hot water make tea, the simplest way to start. Young leaves are milder and are better added to salads or soups, since older leaves turn tougher.
Why Four-Leaf Clovers Are Rare
Roughly 1 in 5,000 clover leaves has four leaflets.47Wikipedia. Four-leaf clover A rare inherited trait may be responsible.48Wikipedia. Four-leaf clover A patch that produced one four-leaf clover is a good place to keep looking. A random change in a growing plant, or a growth error triggered by conditions, can also produce one.49Wikipedia. Four-leaf clover
Look across a patch rather than at single leaves, watching for a square shape. Most finds are white clover, the common lawn type. Oxalis with four leaflets is often sold as lucky clover but is not true clover.