Red Clover

Trifolium pratense

 

The word “trifolium” refers to the three leaves on this, and other clovers.  There is a high demand for good quality red clover blossoms, but the price will also need to be high to pay for the labor intensive nature of harvesting this crop.  Historically valued for its use in controlling coughs, bronchitis, and skin problems, red clover is now known to contain phytoestrogens, which have several important properties.

 

Family: Fabaceae/Pea
Life Cycle: Herbaceous, short lived perennial, zone 3-9.
Native:  
Indigenous to Europe, central Asia, northern Africa and is naturalized in many other parts of the world.
Height:
12 to 24 inches
Sun:
Full sun to partial shade
Soil:
Any soil.  Will fix it’s own nitrogen, but will require some fertility; phosphorus and potassium, to yield well.
Water: 
Moderate
Flowering:
Flowers are large, pink blossoms that appear throughout the summer months, with a particularly large flush in mid-spring/early summer.
Propagation: 
Some say that seed germinates readily in the field (is probably scarified first), while others suggest that seed must be stratified for several weeks before sowing directly in the field. Germination takes 7-10 days with a germination rate of about 75%.  Space 12 inches apart in row. When grown as a forage crop, direct seed in early spring or fall, or broadcast seed into standing oats or wheat in early to mid-March for a clover crop, after the grain is harvested.  Since red clover is a common forage crop, the seed won’t be expensive (as compared to many other herb crops).
Pests: 
Pests were not a problem in our field plots, except for rabbit and deer feeding.  With only 5 red clover plants per plot, scattered here and there, among other plants that are less delicious, we found that our four-legged friends liked to “eat dessert first.”  In a larger, solid seeded field of red clover, this problem would probably not be noticed.  One reference reported some powdery mildew on the leaves and flowers in the late summer and early fall.  There is also a root weevil that is common in many parts of the country, that limits red clover’s productive stand life to about 2 to 3 years, so plan on rotating this crop.
Harvesting:
Harvest the flowers carefully  by hand in the early morning while the dew is still on the plant.  Clover will bruise easily so handle with care.  Place the flowers on a screen in one layer and allow them to dry naturally.  When fully dried they have a deep purplish red color. Store them in a glass jar or paper bags away from direct heat and light until they are ready to be used.
Parts used: 
Flowers, fresh or dried.  Some use the dried herb, or leaves.
Used as:
Infusion, tincture, syrup, elixir, lozenge, medicinal food, ointment, salve, cream, balm, honey.
Medicinal Benefits: Red clover is reported to have antispasmodic and expectorant effects, and also promotes the skin’s healing process, including use for athlete’s food, sores, burns, and ulcers.  Traditional uses also include use for coughs, bronchitis, and whooping cough.  It has also been used as an anti-cancer remedy.  Science has not confirmed red clovers’ many traditional uses, but has identified many biologically active compounds, including phytoestrogenic isoflavones, which activate estrogen receptors in mammals.  Standardized extracts of red clover are sometimes sold, which contain 8 times the amount of phytoestrogens consumed in the typical diet.  These same phytoestrogens can cause physical problems with cattle fed late cut hay, and reduced fertility/conception rates in sheep that graze on red clover pasture.  Red clover also contains volatile oils and cyanogenic glycosides.  Though red clover leaves are sold by several herb companies, there is not much written about the medicinal value of the leaves, as compared to the flowers, which have been used and studied more.
Market Potential: 
High for good-quality flowers.  Flowers sell for between $5.70 - $47.03/lb dw, and the herb (leaves) for $8.00 - $52.80.  Because the harvesting is so labor intensive, one might want to secure a market, probably local, to obtain a return for your time investment.

 

KSU Field Trial Data - 2000-2002.  

RED CLOVER

 

 

 

 

 

 

1st Year

2nd Year

3rd Year

Average

Comments

 

 

 

 

 

 

Location/Years

4

2

0

 

 

Survival (%)

57.3

48.3

--

52.8

 

Vigor (rating)

3.5

3.5

--

3.5

 

Height (cm)

37.0

38.0

--

37.5

 

DW Herb (g/plant)

67.5

140.8

--

 

Flower yield estimate: 25% of 2nd yr dry weight is flowers, or 35.2 g/plant.  See price calculations below.

DW Root (g/plant)

9.9

38.6

--

 

 

Maturity (rating)

3.8

5.2

--

4.5

 

Insect (rating)

0.6

0.4

--

0.5

 

Disease (rating)

0.5

0.2

--

0.3

 

 

 

 

 

 

 

Est. planting density

43560

43560

--

 

Assume a solid seeded stand, with at least 1 plant per ft2 (1’ x 1’ spacing).

Plant density x survival.

24,960

21,039

 

 

21,039

kg/acre DW (g/plant x # of plants - tops)

1685

2962

 

 

741 (flowers)

Est. Marketable Yld

(DW lb/acre tops)

3711

6525

 

 

1631 (flowers)

Yld x ½ of “low” price

$14,844

$26,100

 

 

$4648

Yld x ½ of “high” price

$97,970

$172,260

 

 

$38,361

 

 

 

 

 

 

 

Summary of field trial data: Red clover was grown under less than optimum conditions in our trials, and we didn’t have the people-power (time) to harvest individual red clover blossoms for yield estimates.  We grew all of the herbs in the greenhouse in the spring, and transplanted them to the field, so that various species could be compared.  Most growers would direct seed red clover.  However, we did get some interesting numbers.  Survival ranged from 20% to 85% for first year transplants, and biomass differed tremendously by location, ranging from 4 to 150 g/plant dw in the first year.  The differences can be partially explained by irrigation, but rabbit and deer feeding at some locations were also a factor.  Solid seeded, large stands of clover probably wouldn’t have this problem, unless one was over-wintering a large herd of deer.

If we make some assumptions, such as that about 25% of the dry weight of the above-ground plant in the second year could be flower blossoms (especially if harvested over several weeks of repeated picking), then a yield of about 1600 lb dw of flowers per acre should be possible.  However, one is more likely to be labor limited than land limited with this crop.  One reference estimated that an experienced, fast picker can pick 1 lb dw flowers per hour, while a more average value is ½ to ¾ lb per hour.  A grower would certainly need a price closer to the $25 to $30 dollar range, than the $5 per lb, to make it worthwhile to grow and harvest.

 Though prices were found for the herb (leaf), it isn’t clear what their medicinal value is at this point.  If you can find a buyer for leaf at these prices, go for it.  That’s one valuable bale of hay!!!