Subterranean Clover Trifolium subterraneum L

Subterranean clover, or simply “sub clover”, is a low-growing annual that forms a dense cover due to a low growth habit and extensive stolons and leaves. This makes sub clover an excellent weed suppressor, even better than vetch. Due to its low growth habit it can even produce seed under heavy grazing pressure which is an added bonus to insure reseeding in grazed pastures.

Sub clover leaves are easy to recognize being heart-shaped and hairy with the majority bearing a black spot. It possesses small white flowers that give rise to a large, “burr” type seed bearing structure that has a unique ability to force itself into the soil thereby actually reseeding itself. Its seed are also the largest of the commercially available clovers.

Tens of millions of acres of sub clover have been planted in Australia and it has become one of the most important legumes in that country’s grassland agriculture. In North America, sub clover it is best suited to climates that have mild, wet winters; especially in states like California, Oregon and Washington. It has also shown good performance in southeastern Coastal Plain area from southern Texas to Florida. Sub clover is generally more tolerant of low fertility and shade than most clovers. It is best adapted to heavier textured soils with good moisture holding capacity. A pH of 5.8-6.5 is recommended for optimal performance.

Sub clover makes most of its growth in mid-spring, but its total seasonal yield is usually not as high as arrowleaf clover, berseem clover, or crimson clover. Sub clover can produce between 3,000-8,500 lbs. DM/A annually as a thick mat of leaves, stems and petioles.