Strawberry Clover
Scientific Name: Trifolium fragiferum L.
| General Information | |
|---|---|
| Usda Symbol | TRFR2 |
| Group | Dicot |
| Life Cycle | Perennial |
| Growth Habits | Forb/herb |
| Native Locations | TRFR2 |
Plant Guide
Alternate Names
Trifolium fragiferum L, ssp, Use soil moisture sensors to measure the soil moisture of Strawberry Clover., Bonannii (C, Presl) Sojak, TRFRB,
Uses
Strawberry clover is mainly used for pasture and in mixtures with grass for hay and silage. It has also been used to a limited extent as groundcover in orchards and vineyards and for green manure cover crop applications. Forage and seeds of strawberry clover are also used by big and small game and upland birds (Stevens and Monsen, 2004).
Status
Consult the PLANTS Web site and your State Department of Natural Resources for this plant’s current status (e.g., threatened or endangered species, state noxious status, and wetland indicator values).
Description
General: Pea Family (Fabaceae). Strawberry clover is an introduced perennial low-growing plant with creeping stems that root at the node (stolons) to spread and it also produces seed. It is subglabrous with slender, pointed trifoliate leaves. Leaf veins are distinctive with veins meeting edge of leaf at right angles. Hairs are present on the petioles and underside of the leaflet. Stipules are mostly conspicuous and become gradually narrowed to apex. Seedlings are initially tap-rooted and stolons that initiate from leaf axils form a prostrate plant network. The inflorescence is globular and compact, 10-12 mm (0.03-0.04 in) diameter, with pink or purplish red florets. When seed is ripe, the florets become reddish and resemble strawberries. Flower heads enlarge to a fuzzy reddish ball approximately 2 cm (0.78 in) in diameter when ripe. The pubescent fruiting calyces contain 1-2 heart-shaped seeds that are light brown in color with dark brown flecks. Chromosome number is 2n=2x=16 and is cross-pollinated by bumble bees and honey bees (Frame, 2005). Plant height is 20 to 35 cm (8-14 in). Strawberry clover resembles white clover in stature. Strawberry clover leaf. FAO, Rome, Italy. Used with permission.
Distribution
Strawberry clover is native to the eastern Mediterranean and southern Asia Minor Countries and has been intentionally and inadvertently spread by man to every continent on earth (Hollowell, 1939). It is grown to a limited degree as a pasture plant in moist alkaline and saline soils in the western and northern Great Plains states (McGregor, 1976). For current distribution, consult the Plant Profile page for this species on the PLANTS Web site.
Adaptation
Strawberry clover is noted for its ability to establish and persist on wet saline and alkaline soils and is adapted to wet meadows, streams and seeps. It is the
Establishment
There are approximately 300, 000 seeds per pound (PLANTS Database) and the seeding rate is 4 pounds Pure Live Seed (PLS) per acre. If used as a component of a seeding mix, adjust to percent of mix desired. For grazing situations, strawberry clover should be limited to 1 pound PLS per acre or 25 percent of the total seed mix (Ogle, et.al 2009). Strawberry clover seed requires inoculation in order to fix nitrogen and also requires the special strain of Rhizobia leguminosarum trifolii (Miller, et. al, 2010), (UC SAREP Online). Seedbed should be clean (weed-free) and firm and seed may be drilled to ⅛ - ¼ inch depth and light but firm soil cover or broadcast seeded followed by culti-packing or a light harrowing. On saline soils, a cover crop of barley is recommended to help establish strawberry clover (Frame, 2005). A cover crop to help establish strawberry clover is not recommended for non-saline sites. Planting should take place in late fall (dormant) or in spring. Late summer planting can be successful if there is adequate moisture (may require irrigation) and time for seedlings to establish before cold temperatures. Seed may contain up to 70 percent hard seed, so if seeding during the growing season, seed should be scarified prior to seeding. Dormant fall planting will allow natural seed scarification. Strawberry clover seedlings are easily established and grow rapidly but do not compete well with weeds (Frame, 2005). Successful stands establish from seeding and natural spread and get better over time (Stevens and Monsen, 2004).
Management
Strawberry clover is tolerant of grazing once the plants have developed strong stolons or runners. It is suited to either rotational or set-stocking and heavy grazing pressure. McDonald, 2006) recommends that a 2-4 inch stand be maintained to reduce shading by grasses so that strawberry clover persists. Close grazing (2 inch stubble height) favors clover persistence and light grazing (grass taller than 4 inches) favors grass growth (Ogle, et. al, 2008). The recommended minimum plant height to begin grazing or haying for most clovers is 4 inches and the minimum stubble height to remain at end of grazing or haying is 3 inches (Ogle, et. al, 2008). Strawberry clover can cause bloat in ruminants and increase the incidence of urinary calculi in sheep. These problems can be managed by maintaining a significant component of grass in the pasture. In waterlogged, mildly saline conditions, tall wheatgrass or ‘Newhy’ RS Hybrid wheatgrass are good companion crops and for non-saline, waterlogged conditions, tall fescue, perennial ryegrass and paspalum are suitable companion crops (McDonald, 2006). When seed is properly inoculated at time of planting, strawberry clover will fix nitrogen from N2 in the atmosphere, requiring little or no additional nitrogen fertilizer. However, legumes require relatively large amounts of phosphorus, potassium and sulphur, and will respond to additions of these nutrients as fertilizer when they are not adequately supplied by the soil. In grass-legume mixtures, it is not possible to supply the ideal combinations of elements for both grass and legume. If nitrogen is applied, the grass will tend to increase at the expense of the legume (Ogle, et. al, 2008). Strawberry clover in mixture with grass is highly suitable for hay but care needs to be taken to avoid the loss of the nutritious leaf from the clover during the curing and bailing process (Frame, 2005).
Pests and Potential Problems
Strawberry clover is susceptible to clover rot (Sclerotinia trifoliorum), clover rust (Uromyces spp.) and root-knot nematodes (Meloidogyne spp.) (Frame, 2005), (UC SAREP Online). Based on observations in California, strawberry clover may attract gophers (UC SAREP Online).
Environmental Concerns
Concerns
Concerns
Strawberry clover spreads primarily by stolons and to a lesser degree by seed and can spread into adjoining vegetative communities under ideal climatic and environmental conditions. Contact your local extension specialist or county weed specialist to learn what works best in your area and how to use it safely. Always read label and safety instructions for each control method. Trade names and control measures appear in this document only to provide specific information. USDA NRCS does not guarantee or warranty the products and control methods named, and other products may be equally effective.
Seed Production
For seed production, plant strawberry clover seed at 1 to 3 pounds PLS per acre in 20-24 inch rows. To facilitate seed production and between-row weed control, it is desirable to plant strawberry clover in spaced rows instead of a solid stand. Seed yields in the United States range from 35 – 265 pounds per acre and average 90 pounds per acre (Frame, 2005). Common strawberry clover is reported to be self-fertile but the variety ‘Salina’ is reported to be self-sterile and needs cross pollination. Self pollinated plants are less vigorous. Placing colonies of honey bees near fields will help increase seed yields (Hollowell, 1939), (McGregor, 1976). Seed is usually harvested in July by swathing to allow the seed to complete maturity and dry followed by combining. Fields should be swathed when most seed envelopes are light brown and slightly damp (from dew) to avoid seed loss due to shattering. Vacuum collection of seed has been reported to be possible but not common. Processed seed may have 40-70 percent hard seed but under proper seed storage conditions, seed will remain viable for a long time (UC SAREP Online), (Frame, 2005). Cultivars, Improved, and Selected Materials (and area of origin) ‘Fresa’ strawberry clover was developed and released by the Department of Crop and Soil Sciences at New Mexico State University in 1982. The original collection was from Turkey and was selected for its low growing habit in southern New Mexico. It remains green throughout the year, but shows some dormancy with extremely high or low temperatures (Curtis and Curtis, Inc.). ‘Salina’ was released by the California Agricultural Experiment Station in 1962. It is palatable to all classes of livestock, can tolerate periods of winter flooding and is suitable for poorly drained soils in low-lying areas (Curtis and Curtis, Inc.). ‘Palestine’, ‘Prinsep Park’, ‘O’ Connors’, ‘Grasslands Onward’ and ‘Grasslands Upward’ are strawberry clover releases developed and used in Australia and New Zealand (McDonald, K. 2006). Acknowledgement The authors acknowledge and thank the Food and Agriculture Organization of the United Nations for use of the photographs in this plant guide. Photographs were obtained from the FAO Grassland Database: http://www.fao.org/ag/AGP/AGPC/doc/gbase/Defaul t.htm
References
Curtis and Curtis, Inc. Strawberry Clover. [Online]. Available at http:www.curtisseed.com/index.cfm?show=10&mid=11&pid=10 (accessed 23July2010). Frame, J. 2005. Trifolium fragiferum L. [Online]. Available at http://www.fao.org/ag/AGP/AGPC/doc/gbase/data/pf000500.htm (accessed 26July 2010). Hollowell, E.A. 1939. Strawberry Clover. Leaflet No. 176. United States Department of Agriculture. U. S. Government Printing Office. Washington, D.C. McDonald, K. 2006. Strawberry Clover. In: Perennial pastures for Western Australia. Department of Agriculture and Food Western Australia, Bulletin4690, Perth. McGregor, S.E. 1976. Chapter 3: Clover and Some Relatives. In: Insect pollination for Cultivated Crop Plants. [Online]. Available at http://www.beeculture.com/content/pollination_handbook/strawberry.html (accessed 20 July 2010). Miller, R., Kaiser, J., Ogle, D. 2010. Legume Inoculation. USDA-NRCS. IDTN26. Boise, ID Ogle, D., St. John, L., Stannard, M., Holzworth, L. 2009. Grass, grass-like, forb, legume and woody species for the Intermountain West. USDA-NRCS. ID-TN24. Boise, ID Ogle, D., St. John, L., Cornwell, J., Stannard, M., Holzworth, L. 2008. Pasture and
Range
Seedings: Planning – Installation – Evaluation – Management. USDA-NRCS. ID-TN10. Boise, ID PLANTS Database. Conservation Plant Characteristics for Trifolium fragiferum. [Online] Available at http://plants.usda.gov/java/charProfile?symbol=TRFR2 (accessed 20 July 2010). Stevens, R. and S.B. Monsen. 2004. Forbs for Seeding Range and Wildlife Habitats. In: Restoring Western Ranges and Wildlands. USDA Forest Service Gen. Tech Rep. RMRS-GTR-136. UC SAREP Online Cover Crop Database. [Online]. Available at Http://www.sarep.ucdavis.edu/cgi- bin/CCrop.exe/show_crop_38 (accessed 20 July 2010).
Prepared By
Loren St. John, USDA, NRCS, Plant Materials Center, Aberdeen, ID Daniel G. Ogle, USDA, NRCS, Boise, ID Derek Tilley, USDA, NRCS, Plant Materials Center, Aberdeen, ID Citation St. John, L., D.G. Ogle, D. Tilley. 2010. Plant Guide for Strawberry Clover (Trifolium fragiferum). USDA-Natural Resources Conservation Service, Aberdeen, ID Plant Materials Center. Edited: 28July2010 LS; 10August DGO; 28July2010 DT; 20August2010 LS; 5August2010 JB For more information about this and other plants, please contact your local NRCS field office or Conservation District <http://www.nrcs.usda.gov/>, and visit the PLANTS Web site <http://plants.usda.gov> or the Plant Materials Program Web site <http://Plant-Materials.nrcs.usda.gov> The U.S. Department of Agriculture (USDA) prohibits discrimination in all its programs and activities on the basis of race, color, national origin, age, disability, and where applicable, sex, marital status, familial status, parental status, religion, sexual orientation, genetic information, political beliefs, reprisal, or because all or a part of an individual's income is derived from any public assistance program. (Not all prohibited bases apply to all programs.) Persons with disabilities who require alternative means for communication of program information (Braille, large print, audiotape, etc.) should contact USDA's TARGET Center at (202) 720-2600 (voice and TDD). To file a complaint of discrimination write to USDA, Director, Office of Civil Rights, 1400 Independence Avenue, S.W., Washington, D.C. 20250-9410 or call (800) 795-3272 (voice) or (202) 720-6382 (TDD). USDA is an equal opportunity provider and employer." Read about Civil Rights at the Natural Resources
Plant Traits
Growth Requirements
| CaCO3 Tolerance | Medium |
|---|---|
| Frost Free Days, Minimum | 180 |
| Frost Free Days, Minimum | 150 |
| Frost Free Days, Minimum | 150 |
| Fire Tolerance | Medium |
| Fire Tolerance | High |
| Fire Tolerance | High |
| Fertility Requirement | Medium |
| Fertility Requirement | Medium |
| Fertility Requirement | Medium |
| Drought Tolerance | Low |
| Drought Tolerance | Low |
| Drought Tolerance | Low |
| Cold Stratification Required | No |
| Cold Stratification Required | No |
| Cold Stratification Required | No |
| Temperature, Minimum (°F) | -40 |
| CaCO3 Tolerance | Medium |
| CaCO3 Tolerance | Medium |
| Anaerobic Tolerance | Medium |
| Anaerobic Tolerance | High |
| Anaerobic Tolerance | High |
| Adapted to Medium Textured Soils | Yes |
| Adapted to Medium Textured Soils | Yes |
| Adapted to Medium Textured Soils | Yes |
| Adapted to Fine Textured Soils | Yes |
| Adapted to Fine Textured Soils | Yes |
| Adapted to Fine Textured Soils | No |
| Adapted to Coarse Textured Soils | No |
| Adapted to Coarse Textured Soils | No |
| Adapted to Coarse Textured Soils | No |
| Hedge Tolerance | None |
| Temperature, Minimum (°F) | -33 |
| Temperature, Minimum (°F) | -3 |
| Shade Tolerance | Intolerant |
| Shade Tolerance | Intolerant |
| Shade Tolerance | Intolerant |
| Salinity Tolerance | High |
| Salinity Tolerance | High |
| Salinity Tolerance | High |
| Root Depth, Minimum (inches) | 12 |
| Root Depth, Minimum (inches) | 12 |
| Root Depth, Minimum (inches) | 12 |
| Precipitation, Minimum | 30 |
| Precipitation, Minimum | 20 |
| Precipitation, Minimum | 20 |
| Precipitation, Maximum | 59 |
| Hedge Tolerance | None |
| Hedge Tolerance | None |
| Moisture Use | High |
| Moisture Use | High |
| Moisture Use | High |
| pH, Maximum | 8.4 |
| pH, Maximum | 8.6 |
| pH, Maximum | 8.6 |
| pH, Minimum | 6.0 |
| pH, Minimum | 6.0 |
| pH, Minimum | 6.5 |
| Precipitation, Maximum | 50 |
| Precipitation, Maximum | 60 |
Morphology/Physiology
| Active Growth Period | Spring |
|---|---|
| Toxicity | Slight |
| Toxicity | Slight |
| Toxicity | Slight |
| Shape and Orientation | Prostrate |
| Shape and Orientation | Prostrate |
| Shape and Orientation | Prostrate |
| Resprout Ability | No |
| Resprout Ability | No |
| Flower Conspicuous | Yes |
| Fall Conspicuous | No |
| Fire Resistant | Yes |
| Fire Resistant | Yes |
| Fire Resistant | Yes |
| Flower Color | Purple |
| Flower Color | Purple |
| Flower Color | Purple |
| Flower Conspicuous | Yes |
| Fall Conspicuous | No |
| Flower Conspicuous | Yes |
| Foliage Color | Green |
| Foliage Color | Green |
| Foliage Color | Green |
| Foliage Porosity Summer | Porous |
| Foliage Porosity Summer | Porous |
| Foliage Porosity Summer | Porous |
| Foliage Porosity Winter | Porous |
| Bloat | Medium |
| Resprout Ability | No |
| Active Growth Period | Spring |
| Active Growth Period | Spring |
| After Harvest Regrowth Rate | Moderate |
| After Harvest Regrowth Rate | Moderate |
| After Harvest Regrowth Rate | Moderate |
| Bloat | High |
| Bloat | High |
| Nitrogen Fixation | Medium |
| C:N Ratio | Low |
| C:N Ratio | Low |
| C:N Ratio | Low |
| Coppice Potential | No |
| Coppice Potential | No |
| Coppice Potential | No |
| Fall Conspicuous | No |
| Lifespan | Moderate |
| Height, Mature (feet) | 0.5 |
| Height, Mature (feet) | 1.5 |
| Known Allelopath | No |
| Known Allelopath | No |
| Known Allelopath | No |
| Leaf Retention | No |
| Leaf Retention | No |
| Leaf Retention | No |
| Foliage Porosity Winter | Porous |
| Lifespan | Short |
| Lifespan | Short |
| Low Growing Grass | No |
| Low Growing Grass | No |
| Low Growing Grass | No |
| Nitrogen Fixation | High |
| Nitrogen Fixation | Medium |
| Growth Rate | Rapid |
| Height, Mature (feet) | 0.5 |
| Foliage Porosity Winter | Porous |
| Foliage Texture | Fine |
| Foliage Texture | Fine |
| Foliage Texture | Medium |
| Fruit/Seed Color | Brown |
| Fruit/Seed Color | Brown |
| Fruit/Seed Color | Brown |
| Fruit/Seed Conspicuous | No |
| Fruit/Seed Conspicuous | No |
| Growth Form | Stoloniferous |
| Growth Form | Stoloniferous |
| Growth Form | Stoloniferous |
| Growth Rate | Moderate |
| Growth Rate | Rapid |
| Fruit/Seed Conspicuous | No |
Reproduction
| Fruit/Seed Persistence | No |
|---|---|
| Propagated by Tubers | No |
| Propagated by Tubers | No |
| Propagated by Tubers | No |
| Propagated by Sprigs | No |
| Propagated by Sprigs | No |
| Propagated by Sprigs | No |
| Propagated by Sod | No |
| Propagated by Sod | No |
| Propagated by Sod | No |
| Propagated by Seed | Yes |
| Propagated by Seed | Yes |
| Propagated by Seed | Yes |
| Propagated by Cuttings | No |
| Propagated by Cuttings | No |
| Seed per Pound | 299371 |
| Seed per Pound | 299371 |
| Seed per Pound | 299371 |
| Seed Spread Rate | Slow |
| Seed Spread Rate | Slow |
| Seed Spread Rate | Slow |
| Seedling Vigor | Low |
| Seedling Vigor | Low |
| Seedling Vigor | Medium |
| Small Grain | No |
| Small Grain | No |
| Small Grain | No |
| Vegetative Spread Rate | Moderate |
| Vegetative Spread Rate | Moderate |
| Vegetative Spread Rate | Moderate |
| Propagated by Corm | No |
| Propagated by Cuttings | No |
| Bloom Period | Early Summer |
| Bloom Period | Late Spring |
| Bloom Period | Spring |
| Commercial Availability | Routinely Available |
| Commercial Availability | Routinely Available |
| Commercial Availability | Routinely Available |
| Fruit/Seed Abundance | High |
| Fruit/Seed Abundance | Medium |
| Fruit/Seed Abundance | Medium |
| Fruit/Seed Period Begin | Spring |
| Fruit/Seed Period Begin | Spring |
| Fruit/Seed Period Begin | Summer |
| Fruit/Seed Period End | Summer |
| Fruit/Seed Period End | Summer |
| Fruit/Seed Persistence | No |
| Fruit/Seed Period End | Summer |
| Propagated by Corm | No |
| Propagated by Corm | No |
| Propagated by Container | No |
| Propagated by Container | No |
| Propagated by Container | No |
| Propagated by Bulb | No |
| Propagated by Bulb | No |
| Propagated by Bulb | No |
| Propagated by Bare Root | No |
| Propagated by Bare Root | No |
| Propagated by Bare Root | No |
| Fruit/Seed Persistence | Yes |
Suitability/Use
| Palatable Browse Animal | Medium |
|---|---|
| Palatable Graze Animal | High |
| Palatable Graze Animal | High |
| Palatable Graze Animal | High |
| Palatable Human | No |
| Palatable Human | No |
| Palatable Human | No |
| Post Product | No |
| Post Product | No |
| Post Product | No |
| Protein Potential | High |
| Protein Potential | High |
| Protein Potential | High |
| Pulpwood Product | No |
| Pulpwood Product | No |
| Pulpwood Product | No |
| Veneer Product | No |
| Veneer Product | No |
| Veneer Product | No |
| Lumber Product | No |
| Berry/Nut/Seed Product | No |
| Berry/Nut/Seed Product | No |
| Berry/Nut/Seed Product | No |
| Christmas Tree Product | No |
| Christmas Tree Product | No |
| Christmas Tree Product | No |
| Fodder Product | Yes |
| Fodder Product | Yes |
| Fodder Product | Yes |
| Palatable Browse Animal | High |
| Lumber Product | No |
| Lumber Product | No |
| Naval Store Product | No |
| Naval Store Product | No |
| Naval Store Product | No |
| Nursery Stock Product | No |
| Nursery Stock Product | No |
| Nursery Stock Product | No |
| Palatable Browse Animal | High |