- Hardiness Zone: 3-7. - Flowering Date: Spring. - Winter Care: None special. - Foliage Type: Mid green, heart shaped leaves 4" - 5". - Pruning: To shape as needed, after flowering. After flowering. - Ideally, each seed germinates and grows into a single plant, but choose more seeds than the number of plants you want to grow just to be on the safe side, in case some fail to germinate. Do not worry if most of them germinate; simply thin seedlings out later. - Fill seed trays or 4-inch peat pots with sterile potting mix, or select a spot outside in the soil. Push each seed 2 inches deep in the soil, and space them 2 to 3 inches apart. - Water the soil deeply with the watering can, until drained water runs out from the drainage holes in the pots. Water the soil frequently. - Place a flat container under each pot or tray to collect drained water. - Cover the seed starter tray with an inverted seed tray, lid, or clear plastic sheet. If using a pot, cover it with a clear plastic sheet. - As well to mimic a greenhouse effect, creating humidity and retaining moisture at all times. Place the seed starter tray in an area with a temperature around 41 degrees Fahrenheit for two to three months, or until the seeds sprout. - Transplant seedlings to their permanent location outside when they develop a set of two leaves. Dig a hole over a spot that receives five to six hours of sunlight every day, with well-drained and slightly alkaline soil. Lower the seedling into the hole and spread its roots. Space seedlings 5 feet apart to provide them sufficient room to spread and grow. Water infrequently but deeply.