- Mimosa plants need lots of sun, so place them in a bright window with access to direct early morning or afternoon sun at the very least. A window with a southern exposure is ideal for these light-loving tropical plants, or you can grow mimosa plants under a special plant grow light if desired. Mimosa plants seem to prefer small pots and will not grow to be very large. Small pots help to prevent root-rot and encourage the mimosa plant to bloom. A 3- to 5-inch pot is ideal. A good soil mixture for the mimosa plant would consist of 15 percent humus, 45 percent sandy soil and 40 percent peat moss. Keep the room temperature where the mimosa plant resides above 65 degrees F and protect it from cold drafts. Ideally, the humidity should be kept at 50 percent; place a bowl of water near the plant if the air becomes too dry.
- Water the mimosa plant once the soil becomes dry. Water the plant until moisture begins to seep out of the bottom of the pot. Do not overwater this sensitive plant. Prune your mimosa regularly during its growth phase to encourage fullness and branching. Mimosa plants that are not pruned can become leggy and unattractive. Fertilize the mimosa plant monthly during its growth phase with a balanced fertilizer designed for houseplants. Do not fertilize it during the winter months. Watch for spider mites; these pests can quickly damage your mimosa plant. Spray the mimosa plant with an appropriate insecticide at the first sign of infestation. Mimosa plants typically live for only 1 to 2 years as a houseplant.
- You can grow Mimosa pudica outdoors during the warmer months or year-round in areas where the temperature stays above 60 degrees F. Soak the seeds in hot water for at least 20 minutes before planting them. Prepare fine, sandy soil with about 15 percent organic matter. Plant the mimosa seeds outdoors in a well-ventilated sunny area in late spring after the last frost date. Seeds will sprout in approximately 14 days. Plant seeds 1 inch apart and thin seedlings to 8 inches apart. Mimosa plants will grow to a height of 12 inches. Keep the plants well-watered throughout the growing season.
