Yellow Blossom Sweet Clover Melilotus officinalis
This drought-tolerant clover produces beautiful yellow flowers and can be used for forage, cover cropping, and more. Sweet clover is a biennial species: it will stay vegetative the first year and produce flowers the second year, before dying.
The origin of the name.
So where does the name “sweet clover” come from? Probably it relates to the fact that when the leaves are crushed, the plant puts out a distinct sweet aroma. In earlier varieties the source of this aroma was identified as coumarin and used to develop the anti-coagulant drug called ‘warfarin’. Since these anti-coagulant properties were found to be detrimental to grazing livestock modern sweet clover varieties have been bred to be low in coumarin.
Really a Clover? No. But a Really Good Legume!
Yellow blossom sweet clover is not a true clover but is probably more closely related to alfalfa. Sweet clover leaves look much like alfalfa, but the margins of alfalfa leaflets are serrated only on the tips. Sweet clover leaflets are serrated around their entire margin. It is typically a biennial, grows 2-6 feet high, and as the name implies, produces yellow flowers. It is used for forage, cover cropping, conservation, and honey making.
When compared to the white flowering types of sweet clover, yellow blossom blooms roughly 2 weeks earlier and also matures earlier, usually grows less upright, possesses finer stems, and is less productive and less winter-hardy. However, yellow blossom sweet clover persists better in pastures and tolerate adverse conditions better than white varieties.
Sweet clover can produce and deposit a high percentage of hard seeds that persist in the soil for many years. This accounts for its consistent volunteering in many areas.
Drought tolerant, winter hardy and so much more.
Yellow blossom is one of the most drought-tolerant of forage legumes and is quite winter-hardy. In temperate climates with mild summers, it can survive and thrive through a second year of production. Sweet clovers grows where alfalfa, red clover and white clover fail, such as on clay pan soils or on sands and tolerates low fertility and wet conditions. Yellow blossom prefers non-acid soil (pH above 6.0).
This plant goes deep.
While not a huge forage producer (under 3 tons/acre), yellow blossom sweet clover has a valuable taproot growth that penetrates deep down in soil - up to five feet. This deep tap root and root branches give sweetclover a greater ability than most other cover crops in extracting potassium, phosphorus and other soil nutrients from insoluble minerals. Root branches take in minerals from seldom-disturbed soil horizons, nutrients that become available as the tops and roots decompose.
Nitrogen producer.
Yellow blossom sweetclover contributes up to 275 lbs. N/A and adding valuable organic matter.
Coat for Optimal Performance
For optimal performance, sweet clover should be inoculated with Rhizobium Sinorhizobium meliloti. This is best achieved with Nitro-Coat®.
Yellow Blossom Sweet Clover Specifications
Planting
- Zones
- Humid or irrigated regions of zones 3-8; acts as annual in zone 9
- Longevity
- Biennial - Vegetative the first year and produces flowers the second year, before dying.
- Ease of Establishment
- Good
- Seeds/lb
- 260,000
- Seeding Rate - Straight
- 8-10 lbs/ac
- Seeding Rate - Mix
- 6-8 lbs/ac
- Seeding Time
- Fall (October-November) or late winter to early spring (February-April)
- Seeding Depth
- 1/4"-3/8"
- Seeding Method
- Broadcast or drilled (preferred)
- Method of Killing/Suppression
- Mowing; grazing; chemical
- Optimal Germination Temperature
- Night temperatures > 40°F
- Seedling Emergence/Vigor
- Good
- Reseeding Potential
- Good
- Root Type
- Tap
Usage
- Grazing Potential
- Fair
- Hay Potential
- Fair
- Use with Wildlife
- Good
- Use in Orchards
- Good
- Use with Row Crops
- Good
- Use with Other Grasses/Legumes
- Excellent
- Bees/Beneficial Insects
- Good
- Compaction Control
- Good
- Erosion Control
- Good
- Weed Suppression Potential
- Good
- Green Manure/Cover Crop Use
- Excellent
- Spreading Capability
- Poor
- N Contribution Potential
- Good
- DM Potential
- Excellent
- Forage Quality
- Good
- Harvest Time Frame (late/early/year-round)
- Late
- Number of Harvest/yr
- 1-2 per year
- Other Comments
- Hard seed so future volunteering is probable; Use only low coumarin varieties for livestock hay or grazing. Better adapted to short rotation pastures.
Tolerance
- Bloat Risk
- High
- Disease Resistance
- Good
- Insect/Nematode Risk
- Moderate; especially susceptible to sweet clover weevil.
- Cold Tolerance
- High
- Traffic Tolerance
- Fair
- Heat Tolerance
- Good
- Drought Tolerance
- Good
- Shade Tolerance
- Good
- Dry Soil Tolerance
- Good
- Wet Soil Tolerance
- Good
- pH Range
- Needs high pH (>6.0)
- Required Fertility (P,K, other nutrients)
- P, K, Ca, Mg needed; minor especially Mo, B also needed.