Caucasus Mountain Spinach
Hablitzia tamnoides Newly-discovered as a permaculture crop, this is a perennial vine native to the mountain forests of Eurasia. Survives the winter in Zones 3-7, and in fact it dislikes mild climates. Too new to have an agreed-upon common name, it is a very hardy perennial, growing 6–9' long for 2–3 months in the very early spring when few other edible greens have surfaced. It’s also tasty: both early shoots and subsequent leaves make a delicious and tender spinach-like vegetable without any bitterness. Moreover, it’s beautiful, and was introduced into Sweden around 1870 as an attractive vine to screen houses with its heart-shaped leaves. And, finally, it is native to the understory of temperate forests, so it thrives in partial shade that most vegetables hate..
I would put it where it would get afternoon shade, unless you live in a very cool climate (Maine, the Pacific Northwest, and the maritime coastal fog belt.) Most of us will want to put it in dappled shade, or in a position with morning sun only.
Plant seeds outdoors in pots in fall or very early spring; they need freezing and cold moist conditions to get them ready to sprout (stratification). Grows slowly the first year. Like many vines, it needs to get a strong root system before the tops can grow rapidly. Takes bitter cold, but is sensitive to flooding, so site on well-drained, humusy soils. Rare. 20 seeds.