OK, here’s another installment about my issues with plant names. Did I hear somebody say “Get a life!”?
The ground cherry Cossack Pineapple came to me through the Seed Savers Exchange in 1987 from Bill Ellis (PA EL B). It was put into the SSE by seed-saver super-hero Will Bonsall (ME BO W), who has the god-like power (in my eyes) to get seed directly out of the USDA National Plant Germplasm System. This particular Cossack Pineapple is the USDA’s PI285705, and came to them from Warsaw, Poland.
I can say for sure it is a member of the genus Physalis, which makes it a close relative of tomatillos (Physalis ixocarpa) and the ornamental Chinese Lantern (Physalis alkekengi). All of these plants have calyxes that form a papery envelope around each fruit, and are members of the nightshade family, which includes tomatoes, peppers and potatoes.
There is a lot of confusion about Physalis species. My Cossack Pineapple is either P. peruviana (aka P. edulis) or P. pruinosa (aka P. pubescens). The USDA lists this accession as P. peruviana, and calls it an annual. However, Taylor’s Gardening Encyclopedia calls P. peruviana a tender perennial, and P. pruinosa a hardy annual. In his booklet Ground Cherries, Husk Tomatoes and Tomatillos Craig Dremann has wisely avoided the annual/perennial issue, except to say that the genus includes annuals and perennials. I have been growing this plant for more than 20 years, and I don’t know. Doesn’t make much difference to me – even if it is a tender perennial, in my climate I have to treat it as an annual. Google Cossack Pineapple and you’ll find this cultivar name attributed to either species. Some of the photos and descriptions match my plants, some don’t.
Cultivation is the same as for tomatoes: start them early inside, transplant after frost danger, feed well. I usually have volunteers, but they bear a lot less fruit than the transplants. The plants are upright (2-3 feet) and spreading. The fruit ripens and forms sugars well even in cool temperatures, which is probably why it became quite popular as a commercial crop in the Ukraine and Poland. This strain has really delicious, sweet subacid fruit with none of the off-flavors often associated with ground cherries. We eat them raw out-of-hand, in salads, and they make fantastic salsa. I love the combination of Cossack Pineapple with cilantro and fresh hot peppers. The trick is to be sure they are completely ripe, which is easy to discern because the husk turns brown and the fruit falls to the ground. They also keep really well. The plants will survive a light frost, so at first frost, I pick all the fruit into a basket, hulls and all, and keep them in the pantry (65 degrees F). Most of the unripe will ripen in the basket, and if you aren’t keeping up with eating them as they ripen, they will dry very nicely. We ate the last of ours this year in early February, but if the harvest had been bigger, we would still be eating them out of the basket.
I think the name Cossack Pineapple may be one of those very generic variety names, which frequently happens with off-the-beaten track species. I do wonder if this plant’s wild origins were in the Andes (if it is P. peruviana), or in eastern Europe. Could it have been collected on a Vavilov expedition to South America, and introduced into the agriculture of the USSR in the twentieth century? I’d love to know more.