Gardener's HQ Guide to Growing Sensitive Plant and Shy Plant
The Mimosa pudica plant is a fun plant to grow because of how its leaves react upon being touched. Upon touch the leaves of this legume droop and fold inwards. This has led to the Mimosa having numerous common names that try to describe this phenomenon. These include Sensitive plant, Shameplant, Touch-Me-Not, and the Zombie Plant.
This contracting of the leaves is a natural defence mechanism and the leaves will typically return to normal a few minutes after the potential danger has disappeared (for most garden and house plants this is nothing more than contact being made by poking with a finger). In addition to touch, the Mimosa pudica Sensitive plant has semimonastic movements upon facing a strong wind, to shaking, and warm temperatures.
This plant has a long spiky stem but tends to creep low. Its length can be up to five feet (1.6 m) but its height will seldom be greater than one and a half feet (45 cm). Mimosa pudica flower in the summertime. Plants are naturally native to Central and South America, but has unfortunately become weeds in other areas; it is considered as an invasive plant species in SE Asia, India, Tanzania, and parts of Australia amongst others.
As is the will of nature, there are natural predators that have overcome the Sensitive Plants defensive mechanism. These include Spider mites that use a web to wrap the leaflets, and thus inhibit the closing of the leaves.
This plant may have use in the control of polluted soils as it is able to readily take up arsenic into its leaves, and thus it may be useful of clearing soils of this toxic compound.
This plant is native to the tropics and thus is usually grown as a summer annual outdoors or as an houseplant. It has become invasive in many areas and can quickly spread as a weed, so please take care to check your local growing sources for information on whether or not to grow it outdoors in your area (especially a problem in hot humid areas). Due to its low tolerance of cold and its ability to spread, it is perhaps best grown as an interesting houseplant.
Unfortunately this plant has a tendency to take over lawns in areas where it grows as an invasive weed. It is best to physically remove the plants. Also consider over watering the grass as a control mechanisn as these plants don't do well in wet waterlogged conditions.
Photograph of Mimosa growing in Thailand
Though native to the America's, Mimosa plants grow well in other tropical countries where they are often regarded as a weed.
Quick Growing and Care Guide
Scientific Name:Mimosa pudica
Common Name (s): Sensitive plant, Shameplant, Shy plant, Sleepy plant, Action plant, Dormilones, Touch-me-not, Zombie plant, Humble plant
Growing Zone (USA / UK Hardiness): As a Perennial 9 to 11; As an Annual USDA zones 2 to 8. UK Hardiness: H1B (outdoors in the summer)
Life Cycle / Plant Type: Perennial usually grown as an annual or as a houseplant.
Plant Height: 12 to 18 inches (30 to 45 cm)
Plant Spread: 60 inches (1.7 m)
Flower Details: Yellow, pink, or Purple. Fluffy. Delicate.
Best Light Conditions: Full sunlight (for best results) or Partial Shade.
Suitable Soil Types: Well drained. Loam. Nutrient poor soils.
Suitable Soil pH: Close to neutral. 6.5 to 7.5
Soil Soil Moisture: Medium moisture. Does not tolerate wet soils.
Sowing, planting, and Propagation: Surface. In a moist seed compost. Winter to middle of spring in hot areas (or anytime indoors at about 21 to 24°C (70 to 75°F). First soak seeds in warm to hot water for two hours before sowing (or/and nick seed with a knife). Germinate in the light. Germination takes about one month. Transplant at a spacing of about three to four feet (1 to 1.2 m).
Care: Regular watering to maintain a medium soil moisture. Susceptible to root rot. Does not tolerate low temperatures or frost. Does not tolerate low light. Fertilise twice a year. Prune to encourage further growth.
Growing Mimosa pudica as an houseplant: Requires direct sunlight, so grow in an appropriately facing sunny window. Thirsty plant, so keep soil moist by watering regularly. Do not waterlog soil as susceptible to root rot. Fertilise with half-strength potassium rich liquid fertiliser. May require pest control to get rid of spider mites. Do not use soapy water.
Best used for: Houseplant, Ground cover. Container.
Closely Related Species:
Miscellaneous: An interesting plant that has been subject to much scientific research. It has been found that in low light (thus poor photosynthesis opportunities) that the plant compromises between sensitivity and energy availability. In order to do this it is able to develop a memory of irrelevant stimuli, such as a constant drop of water on the leaves. Poisonous seeds, don't ingest.