About Rose Mallow: This close cousin of hibiscus comes from the Mediterranean region, and was first recorded as "Spanish Summer Mallow" in the 1633 edition of Gerard's famous Generall Historie of Plantes. The genus name "Lavatera" honors a Swiss horticulturist named J. R. Lavater, while the species name "trimesteris" has a literal meaning of "three months," noting the time of the plant's development and blooming.
Rose Mallow Germination: Direct sow as soon as the soil can be worked in the spring. Sow the seed just below the surface of the soil and keep it lightly moist until germination, which should occur within 14-21 days. For a longer bloom time, sow additional seed every two weeks. Seed can also be started indoors 6-8 weeks before the last frost, for an earlier start. Plant three seeds each in large peat pots, planting them just below the surface and keeping the soil lightly moist until germination. Transplant seedlings after the last frost, taking care not to disturb the sensitive roots.
Growing Rose Mallow Seeds: Water the young plants occasionally as they develop, since dry soil at this stage can stunt their growth. In addition to being extremely hardy in cold temperatures, mature plants can tolerate some drought and need little attention, though support may be helpful for taller plants. Do not over fertilize mature plants, as this tends to produce abundant foliage and few blooms. Transplanting is not recommended, since this plant does not like having its roots disturbed. Deadhead spent flowers for continued bloom, leaving some at the end of the season to produce seed for another crop next season.
Harvesting Rose Mallow: These delicate blossoms make excellent cut flowers. Choose stems with flowers that have just opened, and place them in water immediately. Strip the foliage that will fall below the surface of the water. Fresh flowers should last approximately 7-10 days. Either single flowers or entire plants can easily be dried.
Saving Rose Mallow Seeds: After the flowers wilt, a papery tan husk will form. The disc-shaped seed head will turn black when ripe. Remove the heads as soon as they ripen, since they will soon fall to the ground when dried; they can also mold if exposed to excessive moisture. Spread the seed heads out to dry, and rub them lightly to separate the seeds. Store the seeds in a cool, dry place.
Detailed Rose Mallow Info: Origin: Introduced US Wildflower Other Common Names: Rose Mallow, Annual Rose Mallow, Tree Mallow Duration: Annual Bloom Time: Late Summer Height: 36-48 inches Spacing: 15-20 inches Light: Full Sun to Part Shade Soil Moisture: Medium USDA Zone: 2-10 Seeds Per Oz: 4,800 Produces a plant with large, rounded green leaves and 2-3" pink flowers with darker pink centers.