Botanical Name: Mimosa pudica
It won't giggle like Elmo, but Sensitive Plant has a big reaction to being tickled. Its leaves quickly fold up -- and the entire stem collapses -- when touched, making it a fascinating plant to watch.
Sensitive plant closes it leaves at night and opens them again in the morning. The leaves also fold up if the plant is shaken or exposed to heat. In fact, high temperatures (75-85°F/24-29°C) may trigger the leaves to close.
It only takes a few minutes, though, for the leaves to slowly unfold and the stems to straighten up. Although recovery is fairly quick, the reaction is slower if the leaves are touched again right away.
The feathery, fern-like leaves are bipinnate (grow in opposite pairs), made up of 15 to 25 pairs of tiny leaflets.
The foliage is attractive on its own, but you'll be captivated by the profusion of pink pompon flowers. Those round flower heads are made up of stamens and will bloom throughout summer.
Mimosa pudica is a perennial shrub, but is often treated like an annual and tossed out, because it tends to deteriorate after flowering. Younger plants are more beautiful, anyway, and sensitive plant seed is quick and easy to grow.
Put your potted plant outside for the summer, if you want, to give it the light it needs to flower. Just don't plant it in the garden. It's considered invasive in warm-climate areas and will spread like a weed.
Sensitive plant is fast growing. Repot when you see roots coming through the pot's drainage holes.
Origin: Central and South Americas
Height: Up to 3 ft (90 cm)
Light: Bright light with some direct sun. They'll thrive under grow lights, too.
Water: Keep soil lightly moist, not soggy. Allow the surface of the potting medium to dry before watering again.
Humidity: Moderate to high (above 50% relative humidity). It's a good idea to use a humidity monitor, rather than guess; indoor air can become extremely dry indoors without our noticing it. Fortunately, boosting humidity near your tropical plant is easy. Set Mimosa pudica on a humidity tray or use a cool-mist room humidifier.
Temperature: Average room temperatures 70-75°F/21-24°C. High heat may cause its leaves to collapse. It's a good idea to keep your plant away from entryways and heat/AC vents.
Soil: Peat moss based potting mix with added perlite or horticultural sand for faster drainage.
Fertilizer: Feed every 2 weeks with a high-potassium liquid or other water-soluble fertilizer -- diluted by half -- while plant is growing.
Propagation: Seeds. Sow Mimosa pudica seed in early spring. The seed coatings are tough and need scarification to help germinate. Use a sharp knife to (gently) nick the seed coating to expose the white inside of the seed. Barely cover the seeds with potting mix. Keep the medium moist and warm. You may want to use a seedling heat mat, if needed, to maintain a constant 70°F/21°C temperature. Seeds should germinate in about a week.