Pour an even mixture of peat moss and light sand into a 4-inch diameter planting container. Pampas grass seeds require loose, well-drained, moist soil for germination. Plant the seeds indoors four to six weeks before the last killing frost in spring. Keep the plants indoors during the first winter to protect young plants from frost if seeds are planted later than spring.
Place five evenly spaced pink pampas grass seeds on the soil surface in the planter. Lightly press the seeds into the soil; do not cover them with potting mix.
Water the soil until moist to the touch, but not soaking wet. Water with a slow drip so the seeds don't wash away.
Cover the planters with a clear, plastic food storage bag. Place the open end of the bag over the planter to allow air circulation and control soil temperature and moisture. Alternatively, you can push straws into the soil around the perimeter of the planter and use them to support clear plastic wrap.
Place the planter in sunny window that receives six to eight hours of direct or filtered sunlight daily. The room temperature should be between 65 to 75 degrees Fahrenheit for best germination success. You can place the planters on a seed germination mat, on top of a radiator or near a vent to provide additional heat in cooler rooms. Water the seeds daily to maintain an even level of moisture in the soil required for seed germination.
Water the seeds as needed to keep it moist to the touch, but not wet. While consistent moisture aids germination, excessive moisture can cause seeds and seedlings to rot before they get well established.
Allow one to two weeks for the pink pampas seeds to germinate and reveal seedlings. If each of the five seeds germinate, leave all the plants in place to grow as a single bunch.
Transplant the pink pampas grass outdoors when plants reach a height of 3 to 4 inches. Plant the grass in holes twice the diameter of the original container, or 8 inches in diameter, and the same height as the pots. Space each plant 8 feet apart to allow the pink pampas to reach maturity. Select a site with full to partial sunlight.
Spread a 2- to 3-inch layer of shredded bark mulch around the pampas grass clumps to aid in moisture retention and help prevent weeds. Do not push the mulch directly against the stems.
Water the plants regularly to keep the soil moist for the first growing season. As plants mature, they should only require irrigation once weekly or more often during hot, dry months.
Fertilize the pampas grass plants with a complete fertilizer, such as 10-10-10, four times a year at a rate of 2 pounds of actual nitrogen per 100 square feet. Broadcast the granular fertilizer evenly around the plants; do not put the fertilizer directly against the plant material.