When to plant pampas grass – for a fabulous ornamental grass

Pampas grass is a wonderful ornamental grass whose lush panicles offer a restful break from the green of a typical yard. Knowing when to plant pampas grass can make all the difference between a generous perennial  plant and a laclustre weedy grass. 

Before learning how to grow pampas grass you need to know when to plant pampas grass to give your plan the best chance of survival. These grasses are an iconic addition to both yards and homes, with dried pampas stems becoming a popular interior design trend in recent years. Adding this plant to your backyard ideas is bound to attract attention for all the right reasons while inspiring relaxation with its long stems and gently swaying. 

Here, we look at the best time to plant pampas grass so you can enjoy the tranquil effects of this popular grass from your own home. 

When to plant pampas grass 

'The best time to plant pampas grass is in the spring time,' says Rachel Crow, garden editor for Homes & Gardens. 'This ornamental plant can take a while to establish its roots despite being a fast grower as it matures, so planting in spring will give it plenty of time to grow strong to survive winter and build the strength required to remain in your garden for years to come.' 

'Avoid planting your pampas grass seeds much after mid-June,' Rachel warns, 'as this might not leave enough time for germination and for roots to fully establish themselves.'

When planting pampas grass seeds, it is important to consider the long term commitment of this type of plant. Much like how to grow ornamental grasses generally, pampas is incredibly easy to grow and can very quickly overrun your garden. It can be difficult to get rid of even six months after planting, so make sure this fast-growing plant is for you before you take on the responsibility. 

Planting pampas grass in late winter

It is possible to plant pampas grass in later winter months if it is planting inside or in a greenhouse, Rachel says. 'Planting pampas grass seeds in trays inside can help the roots germinate more quickly and grow into robust seedlings. Transplanting these established plugs in spring into an outdoor garden will help to boost their growth.'

When to propagate and plant pampas grass

'Pampas grass spreads rapidly so it is a good idea to split your established plants each spring to prevent them from completely taking over an entire area of your garden,' recommends Rachel.

If you are planning to propagate a section of pampas grass this is best done around the same time as planting pampas grass as a seed. 'Early spring time is a busy time for pampas grass owners,' Rachel continues. 'Learning how to take plant cuttings and propagating a section of a pampas plant in early spring will allow the plant an entire growing season to establish a stable root system.'

How long does pampas grass take to grow? 

Pampas grass takes approximately 21 days to germinate and will reach its full height within a few months. If your pampas grass was planted as a seed, however, it will not flower for the first two years after planting. Once pampas grass has flowered, the plant spreads quickly - much like its distant cousin, the bamboo plant. 

What month does pampas grass flower?

Despite being planted in spring, pampas grass (once mature at two years old) will flower in the later summer months - most likely September. If weather remains temperate, these blooms can last for months before finally dying back to survive the frosts.