Pampas grass is a quick-growing ornamental grass, perfect for sunny gardens with well-drained soil. This grass is popular in many areas because it is large, easy to grow and produces attractive white, silver or pink plumes. In California, however, pampas grass is often considered a nuisance plant because it grows so large and can take over areas very quickly. You can grow pampas grass in a large container or outdoors. If you live in the northern states where winters are bitterly cold, your best bet (if you want it to survive several seasons) is to plant it in a large container so you can bring it in during freezing weather.
Till a sunny area of your garden with a rake or shovel (unless you are growing the grass in a container). You don’t need to till it deeply--just a couple of inches down will do and three feet or more in diameter. If using a container, fill it with lightweight potting soil.
Add sand and sphagnum moss if your garden soil is hard clay and mix it in well. Pampas grass doesn’t mind being wet, but it does want good soil drainage.
Fill a cup or a small (1 gallon) bucket with soil and set it aside. Sprinkle pampas grass seed over the newly tilled and amended soil. Outsidepride.com states that using 100 seeds in an area 2 feet in diameter should yield a 2- to 3-foot clump of pampas grass. If you are growing this in a container, use half of the recommended amount of seeds.
Use soil you collected earlier in the cup or bucket to sprinkle over the seeds. They do not need to be buried--this is mostly to keep them from being blown away in the wind or eaten by birds.
Moisten the soil using a watering can, sprinkler or garden hose. Keep the soil moist until the seeds germinate. You should see results within two weeks.