I guess I won't be growing any seed today!!! I opened the packet and there was no seed!!!!! I called the company and she said she would replace it - how funny. She actually told me the first year the grass would get about 1 foot, then next year it would grow very large.

I've never heard of any ornamental grass, including Cortaderia (Pampas Grass), reaching 20 feet in height.

In your climate, Pampas Grass should reach at least 7-8 feet, after growing for 3-4 years. It may not, however, be winter hardy in your zone. I think I some cultivars of Cortaderia are hardy to zone 6, but you might have to look for hardier varieties.

Try the link below, for grasses that are specific to colder zones.

Here is a link that might be useful: Bluestem

The packet says it can reach 12 - 20 ft when established. It also says it can be grown as an annual where not winter hardy - it is hard to tell what it will do here - our winters are weird! Thanks for the link. need4nature

Hi need4nature,

Everybody has a different opinion about how hardy Cortaderia is, but it's pretty unlikely that it will survive the winter in z5. If you want the most similar z5 hardy grass, get Saccharum ravennae (Erianthus r.), Hardy Pampas Grass.

Good luck,
Skybird

It certainly gets to near 20 feet here in New Zealand, including flower stems. It grows very easily from seed, so much so that it is a banned plant with serious weed potential. Seeds can germinate 20 miles away from nearest plant, so germination must be easy. It grows everywhere in NZ, but the coldest possible places here are about zone 7, so cant comment on your z5.

The leaf margins are extremely sharp when rubbed in towards the plant, I got a few nasty cuts as a child. I wouldn't let my children play around any (ages 1,3,5).

The other problemw with this plant are that it spreads about as wide as it is high, unless eaten by animals or controlled mechnaically. It also produces a lot of dead material, harbouring rodents and creating a fire risk.