When to red clover?

Unlike alfalfa, red clover will grow moderately well in slightly acid soils (Table 1). However, maximum yields are obtained when soil pH is 6.0 or higher.

Red clover, a short-lived perennial, usually produces two or three hay crops per year. It is characterized by rapid spring growth and low winterhardiness, which contributes to its short-lived nature.

Growth habit varies from erect to prostrate. Numerous stems with large trifoliate leaves arise from the crown region each year. Red clover has a thick tap root that grows to a length of 24-36 inches. Lateral roots arising from the tap root are concentrated mainly in the upper 5 inches of the soil. Small ovoid, pinkish, nitrogen-fixing nodules can be found on the lateral roots if the plant is actively incorporating atmospheric nitrogen into protein nitrogen.

Look for good disease resistance and persistence in a red clover variety. Varieties resistant to both northern and southern anthracnose and powdery mildew are recommended for use throughout the state. Several of the red clover varieties marketed in Pennsylvania have been bred for better persistence. With proper management, you can expect these varieties to persist for two to three years after the establishment year. Refer to the current Penn State Forage Trial Report for red clover variety performance and resistance information.

Red clover can be established as a pure stand, with or without a companion crop, seeded with forage grass, or sod-seeded into a grass sod to improve the existing stand. Each situation has special requirements that should be considered.

Seeding red clover in the spring (April to early May), alone or with a spring oat companion crop in a conventionally prepared seedbed, is common. Best clover stands result if oats are seeded at about 1.5 to 2 bushels per acre. Harvesting the oats early for silage is recommended because this will greatly reduce competition with the red clover. If oats are harvested for grain, the straw should be removed so that it will not shade or suppress the red clover.

Red clover direct seeded in the spring without a companion crop will yield less total forage than when seeded with a companion crop to be harvested as a forage. However, a larger portion of the forage will be red clover when seeded without the companion crop. Use of herbicides may be necessary when direct seeding red clover without a companion crop. Direct seedings of red clover can be made by broadcasting, band seeding, or fluid seeding. Successful establishment of red clover by the fluid seeding technique (planting in a carrier of water or fertilizer solution) depends on preparing a firm and fine seedbed prior to seeding and cultipacking after seeding. Fluid seeding requires special equipment; therefore, a custom applicator is recommended.

Red clover can be no-till seeded and is the easiest legume to establish using this method. Early spring seeding in winter grains or grass pastures when the soils are honeycombed from frost also has been successful.

Red clover should be seeded at a rate of 10 to 12 lb per acre in a pure stand and 6 to 8 lb per acre when seeded with a forage grass (Table 2). Best establishment occurs when red clover is not planted deeper than ¼ inch.

To ensure adequate nodulation, red clover seed should be inoculated with Rhizobium trifolii bacteria and a sticking agent just before seeding. Preinoculated seed should be kept in a cool, dark place to optimize survival of nitrogen-fixing bacteria. For additional information about nitrogen-fixing bacteria or the inoculation process, see Inoculation of Forage and Grain Legumes.

Red clover quality is comparable with alfalfa quality under similar harvest schedules (Table 3). However, intake by the consuming animal is generally greater for alfalfa than red clover. Red clover quality does not decline as rapidly with maturity as does alfalfa quality. This means a longer period over which high-quality forage can be harvested.

Spring-seeded red clover can be harvested three times during the seeding year if growing conditions are favorable. This more aggressive harvest management in the seeding year than has traditionally been implemented provides greater forage and nutrient yields and has not negatively affected yield in the year after establishment. In addition, the third harvest during early September will help maintain better stands the following harvest season. Initial harvest 60-70 days after seeding and subsequent harvest on a 30-35 day interval will generally allow for three harvests during the seeding year.

Established red clover stands should be harvested at prebloom or early bloom. This harvest timing is a compromise between red clover yield and quality. Traditionally, three annual harvests are made in most of Pennsylvania. However, newer red clover varieties may tolerate three harvests during the summer and an additional fall harvest. The fall harvest should be made only if adequate herbage is present to offset the cost of harvesting. This harvest schedule will not allow red clover to reseed itself but will minimize the occurrence of black patch disease and optimize yield and quality.

Red clover silage, if properly harvested and stored, provides a high-quality forage. However, red clover is more difficult to cure for hay than other legumes. Establishing with a forage grass will decrease red clover's curing time. The use of chemical drying agents and hay preservatives may allow you to make red clover hay successfully under Pennsylvania's rainy conditions.

Soil tests are required for proper determination of soil nutrient availability. In soils with a pH below 6.0, adding lime is essential to make the soil less acidic and to improve red clover's nitrogen-fixing activity. Nutrients should be added to the soil on the basis of a soil test. Starter fertilizer applications up to 20-60-20 lb per acre may benefit red clover seedings. Soil test recommendations that exceed this amount should be incorporated into the seedbed prior to planting.

Nitrogen (N) is essential for amino acid and protein production. Atmospheric N is captured (fixed) and converted into plant N by well-nodulated plants. On acid soils with pH less than 5.5, nodulation and N fixation are suppressed and fertilizer N should be supplied for vigorous growth. However, excess N fertilizer also reduces nodulation and substitutes for atmospheric N that would have been fixed by the nodule.

There are several good reasons for growing forage legumes when feasible. These include biological nitrogen fixation, possible extension of the grazing season, increased forage yield (especially compared to grasses receiving little or no nitrogen fertilizer), and improved forage quality.

Factors to consider in selecting a legume to plant can include producer objectives, soil types, sites, and grass species present.  No one legume is right for every field or even every farm. Regardless, red clover is a forage legume that is widely adapted in the eastern United States, dependable, easy to grow, and quite productive. “Mammoth” is a one-cut type of red clover  grown in the northern US; “medium” is a multi-cut type grown throughout the eastern US. Medium type varieties recently developed in the Deep South are more productive and stress tolerant in the Southeast than varieties developed farther north.

Red clover blooms are actually lavender or reddish-purple in color.  Crimson clover, which blooms in early spring and has a much brighter crimson colored bloom, is an annual that can only come back from seed.  Red clover is a biennial that can live for two years when planted in a suitable site and managed properly.  Red clover normally begins blooming until in April, but may continue to bloom in spring and even early summer.

Red clover can be grown on many soil types as long as the soil pH is around 6.0 to 6.5, the soil is relatively fertile, and a reasonable amount of soil moisture is present during the growing season.  Red clover plants will typically live for two years in heavy or moist soils, but in sandy soils in the Deep South, they normally act like an annual.

Red clover is usually grown with a perennial grass, particularly tall fescue, orchardgrass, or dallisgrass.  However, because of its upright growth habit, it can be grown as a companion legume in a johnsongrass hayfield or even with bahiagrass or bermudagrass on some sites.  It is also sometimes grown with ryegrass or small grain, especially when these forages are being grown for hay or silage.  It is not as grazing tolerant as white clover, so should be rotationally grazed to allow the clover plants some rest and to favor good regrowth.

The wide adaptation and excellent seedling vigor of red clover makes it one of the easiest clovers to establish. It is often drilled into thin, weakened, or killed grass sods.  In general, rates of 6 to 12 pounds of seed per acre are recommended, and the ideal seeding depth is about ¼ inch.  Most commercially available seed of red clover is pre-inoculated.  Good seed-soil contact helps ensure establishment, so use of a cultipacker should follow broadcast seeding on a prepared seedbed.

Red clover is most commonly planted in autumn in the Lower South, but if planted in fall in an area where there is a high cricket population, it is advisable to treat with an insecticide. Late winter plantings also may be successful, especially in the mid- and upper South.  Regardless of planting date, success is unlikely if the clover is planted into a thick, vigorous perennial grass sod.  In such a situation, the grass should be severely suppressed by some combination of heavy grazing, spraying an herbicide, or by tillage.  If only a thin stand of grass is present, it may be possible to obtain a stand by simply grazing the grass closely and broadcasting red clover seed, especially if the soil is scratched through use of a drag harrow or similar tool.

Red clover is known both as a cover crop and forage crop and is available in many regions, such as the northeast, mid-Atlantic, and midwest areas. Depending on what you use it for, the seeding time for red clover will differ.

But generally speaking, people often seed this plant in late summer and early fall (around August to November) to improve the soil. To provide grazing for animals, farmers will instead throw and grow clover seeds in spring after the last frost, around March or April. Read below for more information on when to plant red clover.

The ideal red clover planting time is the one we mentioned in the intro—or, to repeat, late summer and early fall for cover crop establishment and after the last frost in spring for red clover used as forage.

However, you will also find people planting red clover outside of these periods, namely in early summer and late winter.

Red clover is classifiable into two types: early-flowering or medium red clover and late-flowering or mammoth red clover. Medium clover varieties produce more hay than mammoth types (up to three crops versus one crop per year), but mammoth cultivars are taller and more suitable for dry environments.

Mammoth varieties are also preferable if you only need supplemental biomass and nitrogen in one growing season, since the cost of medium clover seeds needs to be offset over multiple cuttings to make them worth it.

Medium red clover includes varieties like Midland, Kenland, Kenstar, Pennscott, Cumberland, Lakeland, Dollard, Chesapeake, and Renegade Red. These are more common in the US than mammoth varieties such as Norlac and Craig.

On the planting dates, check your soil and avoid areas that are soggy or wet from rain. Till the ground to remove weeds and inoculate the seeds with Rhizobium bacteria if necessary. However, I recommend buying pre-inoculated seeds so that you have one less thing to do.

Once the preparation’s ready, plant red clover in well-drained soil with a pH of 6.0 to 8.0, or aim for a range of 6.2 to 6.5 if you’re after high yields.

Note that the seeding rates can vary, depending on whether you’re mixing or planting clover with other crops, your location, plus methods of sowing (broadcast seeding, drilling, or cultipacker, to name a few).

You can overseed and mix red clover with many crops, but we’ll focus on grass here, given that the two make great pastures for grazing animals.

Before sowing, mix your clover and grass seeds in a 1:1 ratio. Plant clover seeds at a depth of ¼ to ½ inch at a rate of about 10 pounds per acre or whatever your variety recommends as the seeding rate for red clover. Don’t be tempted to push the seeds deeper into the soil, or germination time may never come.

It’ll take around a week for sprouting to occur, provided the temperature ranges from 41 to 59℉, but you don’t have to worry if you winter-seeded clover, considering the seeds can survive freezing weather.

Red clover characteristics allow it to grow under both full sun and partial shade, so there’s no need for you to fuss about its sunlight requirements—three to four hours of direct sunshine per day should suffice. Watering when the soil is dry, however, is more important.

Check the planting area every day or every few days and irrigate it in the morning so that the ground has time to dry before evening comes. This practice minimizes chances of fungal disease, especially if you avoid wetting the flower heads or leaves when caring for the red clover.

You may also fertilize the soil after planting, but as with most crops, the formula to use depends on your garden’s condition. Conduct a soil test, or use 20 pounds of nitrogen with twice as much potash and three times as much phosphate.

Note that nitrogen is unnecessary when you’re seeding red clover with grass or when the red clover has become established.

What are the benefits of red clover?

If you’re unsure whether to plant red clover, here are some benefits to help you decide:

How long does it take for red clover to grow?

It takes sixty to seventy days for red clover to become harvestable, so you can plant and harvest red clover for deer, cows, and turkeys in a very short time. White, crimson, and ladino are other types of clover for deer worth considering.

Does red clover come back every year?

Is red clover annual or perennial? Red clover is actually a perennial. Don’t mistake it for crimson clover, as despite the two having similar names, crimson clover is an annual plant that’s hardy to zone 6 and not zone 4 like red clover.

You will see red clover reseed itself and come back for up to three years if you live in northern states. However, in the south, such as areas like Florida, southern Georgia, and southern Mississippi, it functions as an annual.

Is red clover easy to grow?

Yes. Red clover is straightforward to plant. Just avoid areas with a lot of weeds and purchase disease-resistant varieties for the best chances at growing them. If you want to, you can also try growing clover indoors as a houseplant.

Simply use a well-drained potting mix and keep the soil moist, plus follow the same seeding depth as the one you use for in-ground planting.

Despite being the representative flower of Vermont, red clover doesn’t just grow in the state’s zone 3 to 5 but also in hotter areas like zone 6, zone 7, or 9 of the United States. As long as you know when to plant red clover, you can enjoy the benefits of this herb, whether you use it as a cover crop, livestock feed, or homegrown vegetable.

Also called: medium red clover (multi-cut, early blooming, June clover); mammoth clover (singlecut, late blooming, Michigan red) Type: short-lived perennial, biennial or winter annual legume Roles: N source, soil builder, weed suppressor, insectary crop, forage Mix with: small grains, sweetclover, corn, soybeans, vegetables, grass forages See charts for rankings and management summary.

Red clover is a dependable, low-cost, readily available workhorse that is winter hardy in much of the U.S. (Hardiness Zone 4 and warmer). Easily overseeded or frostseeded into standing crops, it creates loamy topsoil, adds a moderate amount of N, helps to suppress weeds and breaks up heavy soil. Its most common uses include forage, grazing, seed harvest, plowdown N and, in warmer areas, hay. It’s a great legume to frostseed or interseed with small grains where you can harvest grain as well as provide weed suppression and manage N.

Crop fertility. As a cover crop, red clover is used primarily as a legume green manure killed ahead of corn or vegetable crops planted in early summer. Full-season, over-wintered red clover can produce 2 to 4 T dry matter/A and fix 70 to 150 lb. N/A. In Ohio, over-wintered mammoth and medium red clover contained about 75 lb. N/A by May 15, increasing to 130 lb. N by June 22 (366).

Two years of testing in Wisconsin showed that conventionally planted corn following red clover yielded the same as corn supplied with 160 lb. N/A, with less risk of post-harvest N leaching. Corn and the soil testing showed that 50 percent of the cover crop N was released in the first month after incorporation, corresponding well with corn’s fertility demand. Post-harvest soil N levels in the clover plots were the same or less than the fertilized plots, and about the same as unfertilized plots (401).

Widely adapted. While many other legumes can grow quicker, produce more biomass and fix more nitrogen, few are adapted to as many soil types and temperate climatic niches as red clover. As a rule, red clover grows well wherever corn grows well. It does best in cool conditions.

In southern Canada and the northern U.S., and in the higher elevations of the Southeast and West, red clover grows as a biennial or short-lived perennial. At lower elevations in the Southeast, it grows as a winter annual, and at lower elevations in the West and Canada, it grows under irrigation as a biennial (120). It grows in any loam or clay soil, responding best to well drained, fertile soils, but also tolerates less well drained conditions.

Many economic uses. Red clover has been a popular, multi-use crop since European immigrant farmers brought it to North America in the 1500s. It remains an important crop thanks to its greater adaptability, lower seeding cost and easier establishment than alfalfa. It can produce up to 8,000 lb. biomass/A.

A red clover/small grain mix has been a traditional pairing that continues to be profitable. A rotation of corn and oats companion-seeded with red clover proved as profitable as continuous corn receiving 160 lb. N/A in a four-year Wisconsin study (400). For more information, see the Wisconsin Integrated Cropping Systems Trial (449) and the final report of this project, partially funded by SARE (328).

Red clover was the most profitable of five legumes under both seeding methods in the trial—sequentially planted after oats harvest or companion planted with oats in early spring. The companion seedings yielded nearly twice as much estimated fertilizer replacement value as the sequential seedings. The work showed that red clover holds great potential to reduce fertilizer N use for corn grown in rotation (401).

In Michigan, red clover frost-seeded into winter wheat suppressed common ragweed growth through wheat harvest and into the summer. The red clover did not provide complete ragweed control, but there was no adverse effect on wheat yield (297).

Red clover sown as a companion with spring oats outperformed the other legumes, which suffered from insect damage, mechanical damage during oat harvest and slow subsequent regrowth. The short season proved inadequate for sequentially seeded legumes with the exception of hairy vetch, which was nearly as profitable as the red clover (400).

The role of red clover’s N contribution in the rotation grew more significant as N prices increased in the late 1990s (and 2007!), even though clover seed price also increased from the original 1989 calculations (398).

Soil conditioner. Red clover is an excellent soil conditioner, with an extensive root system that permeates the topsoil. Its taproot may penetrate several feet.

Attracts beneficial insects. Red clover earned a co-starring role with LOUISIANA S-1 white clover in pecan orchard recommendations from Oklahoma State University. Red clover attracts more beneficials than white clover, which features higher N fixation and greater flood tolerance than red clover (261).

Two distinct types of red clover have evolved from the same species. Be sure you plant a multicut cultivar if you plan to make more than one green manure cutting, or to maintain the stand to prepare for a late-summer vegetable planting.

Medium red clover. Medium red (some call it multi-cut) grows back quickly, and can be cut once late in the seeding year and twice the following year. For optimum N benefit and flexible cropping options from the planting (allowing it to overwinter as a soil-protecting mulch), you can use it for hay, grazing or seed throughout the second season. Seed may be up to 25 percent more expensive than single-cut. See Chart 3B: Planting.

Mammoth red clover produces significant biomass and as much N as medium red in a single first cutting, but does not produce as much total biomass and N as medium red’s multiple cuttings over time. Use this “single-cut” red clover where a field will be all-clover just during the seeding year. Slow-growing mammoth doesn’t bloom the establishment year and regrows quite slowly after cutting, but can provide good biomass by the end of even one growing season.

A single cutting of mammoth will give slightly more biomass—at a slightly lower cost—than a single cutting of medium red. Where multiple cuttings or groundcover are needed in the second season, medium red clover’s higher seed cost is easily justified (197).

Some types of mammoth do better overseeded into wheat than into oats. ALTASWEDE (Canadian) mammoth is not as shade tolerant as MICHIGAN mammoth, but works well when seeded with oats. MICHIGAN mammoth shows the best vigor when frostseeded into wheat, but is not as productive as medium red (229).

In spring in cool climates, red clover germinates in about seven days—quicker than many legumes—but seedlings develop slowly, similar to winter annual legumes. Traditionally it is drilled at 10 to 12 lb./A with spring-sown grains, using auxiliary or “grass seed” drill boxes. Wisconsin researchers who have worked for several years to optimize returns from red clover/oats interseedings say planting oats at 3 to 4 bu./A gives good stands of clover without sacrificing grain yield (398).

Red clover’s tolerance of shade and its ability to germinate down to 41° F give it a remarkable range of establishment niches.

It can be overseeded at 10 to 12 lb./A into:

Whenever possible, lightly incorporate clover seed with a harrow. Wait at least six weeks (check labels!) to establish a red clover stand in soil treated with pre-emergent herbicides such as atrazine.

For peak N contribution, kill red clover at about mid-bloom in spring of its second season. If you can’t wait that long, kill it earlier to plant field corn or early vegetables. If you want to harvest the first cutting for hay, compost or mulch, kill the regrowth in late summer as green manure for fall vegetables (197). If avoiding escapes or clover regrowth is most important, terminate as soon as soil conditions allow.

Actively growing red clover can be difficult to kill mechanically, but light fall chisel plowing followed by a second such treatment has worked well in sandy loam Michigan soils.

To kill clover mechanically in spring, you can till, chop or mow it any time after blooming starts. You can also shallow plow, or use a moldboard plow. Chop (using a rolling stalk chopper), flail or sicklebar mow about seven to 10 days ahead of no-till planting, or use herbicides. Roundup Ready® soybeans can be drilled into living red clover and sprayed later.

A summer mowing can make it easier to kill red clover with herbicides in fall. Michigan recommendations call for mowing (from mid-August in northern Michigan to early September in southern Michigan), then allowing regrowth for four weeks before spraying. The daytime high air temperature should be above 60° F (so that the plants are actively growing). When soil temperature drops below 50° F, biological decomposition slows to the point that mineralization of N from the clover roots and top-growth nearly stops (229).

In Michigan, about half of the total N fixed by a legume will mineralize during the following growing season and be available to that season’s crop (229). However, Wisconsin research shows release may be faster. There, red clover and hairy vetch released 70 to 75 percent of their N in the first season (401).

Rotation niches for red clover are usually between two non-leguminous crops seeding with oats or frostseeding into wheat or barley are common options (34). The intersowing allows economic use of the land while the clover is developing. This grain/red clover combination often follows corn, but also can follow rice, sugar beets, tobacco or potatoes in two-year rotations. For three-year rotations including two full years of red clover, the clover can be incorporated or surface-applied (clipped and left on the field) for green manure, cut for mulch or harvested for hay (120).

Red clover in a corn>soybean>wheat/red clover rotation in a reduced-input system out-performed continuous corn in a four-year Wisconsin study. The legume cover crop system used no commercial fertilizer, no insecticides and herbicides on only two occasions—once to-spot spray Canada thistles and once as a rescue treatment for soybeans. Rotary hoeing and cultivating provided weed control.

Gross margins were $169 for the corn>soybeans> wheat/red clover and $126 for continuous corn using standard agricultural fertilizers, insecticides and herbicides. Top profit in the study went to a corn>soybean rotation with a gross margin of $186, using standard inputs (272, 398, 167).

Ohio farmer Rich Bennett frostseeds redclover (10-12 lb./A) into wheat in February. He gets a decent stand of clover that keeps weeds down in summer after wheat harvest. The clover overwinters and continues to grow in spring. He waits as long as possible, and then kills the clover with a disc and roll (two passes) in late April and plants corn. He doesn’t add any fertilizer N and the corn averages 165 bu/A on his Ottokee fine sandy soil.

If summer annual grasses are a problem, red clover is not your best option because it allows the grasses to set seed, even under a mowing regime.

If poor establishment or winterkill leads to weed growth that can’t be suppressed with clipping or grazing, evaluate whether the anticipated cover crop benefits warrant weed control. Take care to completely kill the cover crop when planting dry beans or soybeans after clover. Unless you are using herbicide-tolerant crops, you have limited herbicide options to control clover escapes that survive in the bean crop (229).

Root rots and foliar diseases typically kill common medium red clover in its second year, making it function more like a biennial than a perennial. Disease-resistant cultivars that persist three to four years cost 20 to 40 cents more per pound and are unnecessary for most green manure applications. When fertilizer N cost is high, however, remember that second-year production for some improved varieties is up to 50 percent greater than for common varieties.

Bud blight can be transmitted to soybeans by volunteer clover plants.

Mow or allow grazing of red clover four to six weeks before frost in its establishment year to prepare it for overwintering. Remove clippings for green manure or forage to prevent plant disease. Red clover reaches its prime feeding value at five to 15 days after first bloom.

Under ideal conditions, medium red clover can be cut four times, mammoth only once. Maximum cutting of medium one year will come at the expense of second-year yield and stand longevity. Red clover and red clover/grass mixtures make good silage if wilted slightly before ensiling or if other preservative techniques are used (120).

If an emergency forage cut is needed, harvest red clover in early summer, then broadcast and lightly incorporate millet seed with a tine harrow or disk. Millet is a heat-loving grass used as a cover and forage in warm-soil areas of Zone 6 and warmer.

Medium red clover has similar upper-limit pH tolerance as other clovers at about 7.2. It is generally listed as tolerating a minimum pH of 6.0—not quite as low as mammoth, white or alsike (Trifolium hybridum) clovers at 5.5—but it is said to do well in Florida at the lower pH. Red clover and sweetclover both perform best on well-drained soils, but will tolerate poorly drained soils. Alsike thrives in wet soils.

Red clover has less tendency to leach phosphorus (P) in fall than some non-legume covers. It released only one-third to one-fifth the P of annual ryegrass and oilseed radish, which is a winterannual brassica cover crop that scavenges large amounts of N. Figuring the radish release rates— even balanced somewhat by the erosion suppression of the covers—researchers determined that P runoff potential from a quick-leaching cover crop can be as great as for unincorporated manure (274).

For early fall plowdown, alsike clover may be a cheaper N source than mammoth, assuming similar N yields.

Red clover and alfalfa showed multi-year benefits to succeeding corn crops, justifying a credit of 90 lb. N/A the first year for red clover (197) and 50 lb. N/A the second year. The third legume in the trial, birdsfoot trefoil (Lotus corniculatus), was the only one of the three that had enough third-year N contribution to warrant a credit of 25 lb. N/A (148).

Cultivars. KENLAND, KENSTAR, ARLINGTON, and MARATHON are improved varieties of medium red clover with specific resistance to anthracnose and mosaic virus strains. They can persist three or even four years with ideal winter snow cover (90). CHEROKEE has performed well in Iowa (384), is suited to the Coastal Plain and lower South, and has superior resistance to rootknot nematode.

Red clover is well adapted to sowing on a prepared seedbed, either in the early spring or late summer (Aug. 15 to Sept. 14). The seedbed should be firm, and the clover seed should not be covered with more than 1/4 to 1/2 inch of soil.