Whoever said that money doesn’t grow on trees was right. It grows on a small, bushy plant. Just one type of currency, though: silver dollars.
You have a couple of options in planning your investment with the aptly named silver dollar plant (Lunaria annua). For quickest returns, sow seed indoors in a seedling flat, filled with moist potting soil. Kept at about 70 degrees Fahrenheit, the seeds germinate within two to three weeks. Plant the seedlings outdoors at the same time that you plant out tomatoes, then harvest your first dollars later this summer. If you plant very soon, you may still be able to get a return on your investment this year.
Despite the annua in the botanical name, silver dollar plant often behaves more like a biennial than an annual, growing only leaves the first year then expiring the next year after making flowers and dollars. The second, and more relaxed, way to grow silver dollar plants is as a biennial. Sow the seeds outdoors sometime in early summer—timing is not critical—to rake in your dollars early next summer.
Whether you try for a quick return on your investment, or choose the more relaxed method of growing silver dollars, give the plants a site with well-drained soil in sun or partial shade. Avoid a rich soil, though, or plants put their energy into making leaves at the expense of flowers and dollars.
The flowers that foreshadow the silver dollars are pretty, but not enough so to warrant giving the plant a prominent spot in your flower bed. A better location is in a separate flower garden just for harvesting of blossoms, a wild area, or nestled and spread out in a showy flower garden among other kinds of flowers.
Silver dollar plant’s flowers have four petals in the shape of a cross, putting this plant in the mustard family, along with broccoli, radish, and alyssum. Usually the flowers are pink or purple, except for one variety with white flowers. For a little more pizazz, there is a variety, “Variegata”, with white margins on its leaves.
Silver dollar plant, along with other members of the mustard family, ripens its seeds within a dry fruit called a silique. As the silique ripens, the two outside halves dry, then fall away to leave the ripened seeds still on the plant and suspended within a translucent and silvery, round septum about the size of a silver dollar. For dried flower arrangements, cut stems just as the outsides of the pods are beginning to yellow, then hang them upside down in an airy location. Once the outsides dry, rub them off with your fingers without damaging the delicate membrane between them.
You might say that the silvery orbs that remain also resemble the moon, leading to another common name for the plant, moonwort, as well as the botanical name Lunaria. Money and honesty go hand in hand, right? Perhaps that’s how silver dollar plants also came to be called “honesty”. Some people say it got that name because you can actually see the seeds within the ripened fruits.
Your initial investment in a silver dollar plant can be made with seeds from a seed packet, or with seeds snatched from a dried arrangement. You will get compound interest on your initial investment because silver dollar plant self-sows, the silver dollars eventually falling off and spreading around the garden to make new plants. You do get an annual return on your investment because they’re soon plenty of second year plants that will bloom the current season as well as new plants that will bloom the following season.
That self-sowing might even give you too good a return on your initial investment. So put your investment where you can keep a close eye on it, or where other equally exuberant plants help check its spread.
Lee Reich, PhD is a garden and orchard consultant; he also hosts workshops at his New Paltz farmden (inquire at leereich.com/workshops).