Gunnera Manicata

Hardiness zones 7-10, (-15°C/5°F, 1°C/35°F) in Winter. Gunneras are considered hardy to zone 7. The leaves will die back in zone 7 and 8 Winters, and will push up through the mulch in the Spring, and grow larger than in the previous year. Protect the plants from frosts during Winter.Plant out in moist, loamy mildly acidic soil and part shade. Of course, such a large plant needs lots of nutrients, so feed it in the growing season. Best in cool Summer areas, it is rarely successful in hot or dry climates. Gunneras grow in specific places in the cloud forests, namely seepage areas where there is a constant, unlimited supply of water. Look at those leaves and imagine how much water they can transpire. That means a lot has to be coming in at the roots. These huge leaves act as funnels, bogarting all the rain and funneling it right to the middle of the plant. They grow well next to streams and natural ponds, where their roots can get right into boggy soil, or else they need a lot of watering throughout the dry months. Germination Sow at 1/16 inch in pots of good seed compost in a warm place to maintain an optimum temperature of 75-80°F (25-27°C). The seeds can be slow to germinate. Keep the seed compost very moist, but never saturated. Seed will germinate in 30 to 90 days, it can be a little more, don't give up. Using bottom-heat and a humidity dome is highly recommended. Bottom heat If your home is on the low side of 70ºF, your seeds will benefit from bottom heat. Give warmth from underneath to stimulate early growth, and to help seeds to germinate. The ideal situation is to maintain the soil temperature at 70ºF. For this, you use an electric soil warming cable kit, or a heating mat that goes under your flats; or any other source of heat. With the proper temperature, you will cut by 2 or 3 the germination time.