Sainfoin is deep-rooted and very drought tolerant. It yields best on deep, well-drained soils, and will not withstand wet soils or high-water tables. It does grow on a variety of soils. I have had it planted on some low ground and it didn’t survive well on the G.R.O. farm.
Sainfoin as a hay and forage crop grows taller than alfalfa, its stem is hollow, there are many leaflets (like a vetch), and it has pink flowers. Sainfoin begins growth in the spring about the same time as alfalfa, but flowers one to two weeks earlier. Early growth may exceed alfalfa but will not out yield alfalfa the rest of the season. Compared with alfalfa, forage dry matter yields of sainfoin are about 20 percent lower under dryland conditions, and may be 30 percent or more lower in irrigated areas. Sainfoin is very palatable and is grazed by livestock in preference to alfalfa. Deer once use to it tend to really love it. Although very coarse, the herbage is highly nutritious.
Since regrowth is very poor, they are best suited to taking one clipping at about the half- to full-bloom stage. Unlike alfalfa, they do not drop their lower leaves; stems remain succulent as the plant matures so that quality does not decrease so rapidly. Yield is often better than that of alfalfa for one clipping, but only 80 to 90 percent as high when two cuttings per season are done. Sainfoin would be a great addition for someone who doesn’t not want to clip as often, perhaps only 1-2 clips per season.
Sainfoin use to be in a program member blend called high and dry. It is an option for dry ground or even ground that has a lot of slope. It would be a conservation type blend. Sainfoin would be seeded with trefoil on dry soils and with white Dutch clover and medium red clover on decent soils with slope.
Sainfoin will last perhaps 7-15 years under well management conditions. Because it is long lasting, it is also slow to establish. This is why we would like to use a nurse crop like oats or 3-way annual clover or something that grows fast and helps naturally suppress weeds. Once it’s established it should be vigorous. I’d not recommend this to be a sole planted crop. It isn’t the most graze tolerant so you wouldn’t want to use high amounts of sainfoin where deer densities are very high.