Friday, June 17, 2016

Tall Grass Clumps By Lake - Weed or Not?

Over the course of the last year, Greg and I have been watching clumps of grass growing down by the lake on the lowest terrace.  He's been after me to get rid of them, arguing that they are weeds;  I've been resisting, feeling that they may be good plants with structural and wildlife value.  They do seem to form discrete clumps and the clumps are quite graceful and attractive.

I haven't been able to find a good grass site to identify them, however, and I don't have a good grass book for reference either.  The above photos were taken in early May.

This photo, of the ligule and sheath, was taken in early April.

For some reason, today has been the day that this identification problem has suddenly felt critical.  I e-mailed the local horticulture agent with the photos of the grass from April and May, but I haven't heard back from him.  So I started to write this blog post, asking for help from the blogging community.  Before I did that, however, I decided that I needed current  photos.

So I went down by the lake and took them.

Here's a different clump of the same species, showing the overall structure, ....

here are the ligules and sheaths,...

and here are the seed heads.

Upon looking at the pictures of the seed heads closely, my mind suddenly told me, "Paspalum."   It didn't tell me which Paspalum, though, so I went to the USDA Plant Profile Database and looked up the genus, checking the ranges given and photographs, if any.

I am sad to report that Greg was probably correct.

I am now pretty certain that this grass is Vasey Grass, Paspalum urvillei.  It is a native of South America and is considered invasive in Hawaii.  It is fairly widespread across the southern U.S. (not including Arizona and New Mexico) and is becoming a problem pasture weed in the Florida panhandle.

A weed is a plant that's out of place - and Vasey Grass is out of place in my yard.

So I've got some hot, sweaty work that needs to be done:  cutting off and bagging all the seedheads before the seeds drop, then rooting out the plants and freeing the soil for other, more desireable species.

On the plus side, though, I really like how the tall clump grass looks along the water's edge.  Now, what more desireable species can I plant there?


Cody Z. said...

Thanks for posting on this. I think the same way and find myself disappointed that a plant is really a weed.

Gaia Gardener: said...

Cody, it is a real pleasure to meet someone who thinks this way, too! Most people seem to think "pull it out first, identify it later." Not helpful!!! Thanks for letting me know I'm not alone in my way of acting..... Cynthia

Anonymous said...

I was so disappointed years ago when my first garlic mustard bloomed and I found out its true identity...
Would wild rice be an option? Too tall? I'm not sure how this replacement would go over with the groundskeeper since it's equally grassy looking!

Gaia Gardener: said...

There are native grasses I can use; I just have to figure out what I want and then clear out enough to plant them! LOL! Lots of work still to be done to even begin to consider our yard as a garden spot.