Hello to all...this is my first time on here initiating a post, but I have been reading from this site for about a year now. My question - does anyone in the PNW have experience with Japanese Blood Grass being invasive? I just put it into a planter 5'x6' and 1' high (bottom open to ground) with a spirea and dward cedar and am wondering if this is a mistake. Any opinions on this are very much appreciated. Thanks.
I have seen small patches of it. If definitely creeps when conditions suitable. Typical species is listed as noxious weed by US government.
It depends on how it spreads. I haven't grown this successfully yet, so I don't know if it travels via deep root runners that would get under a 1' high barrier, or if it creeps along the surface. Understanding how a plant travels is essential to keeping it contained. If, for example, it spreads by seed, then containerizing it at all is pointless! I'm guessing that with the bloodgrass, you can safely experiment, in part because of its marginal hardiness, and in part because I don't think it is hard to remove in case it does escape.
Thanks for all the replies... I've been doing a bit more searching on the internet and I read a lot that says to be careful not to let the grass revert to "all green" blades (supposedly the invasive type that will seed and take over) - went out and looked at mine and half of it is all green. I think I will be pulling this one out.
Just bought some blood grass yesterday and thought that I would ask if anyone knows any more information (than what was posted already) about how deep of a barrier to put in place to keep it contained. I was thinking about 10-12 inches. It does get a little bit rampant around here so I'd like to contain it.
I know you are all very far away from Arkansas, but as of June this year Imperata cylindrica, Japanese Blood Grass has been added to our state's Noxious weed list. Here it is on a "no plant, seed or reproductive structure may be sold or utilized in plantings in Arkansas" status. It has been sold a lot in our garden centers and nurseries, infact we have a little bit we used as an annual in one of our color displays, oops! I just read about it in a newsletter distributed by our University of Arkansas Division of Agriculture this morning.
I have used it, and I've seen a lot of yards with it. In west Portland suburbs, I would walk by 3000 to 4000 homes in well landscaped neighborhoods on years where I advertised direct to properties. I'd check out every yard, and note the various plants, and how they changed each year. Japanese bloodgrass can creep, and when it does, it spreads into shrubs like azaleas, or perennials like Dianthus, etc.. Apparently, the better prepared the soil is, the more it spreads. You can try it, and you will know within 2 years if it will spread. If it is a nuisance, it won't be hard to get rid of if you need to, and if you take care of it soon.
The garden cultivar is Imperata cylindrica 'Rubra'. I haven't seen it flower or revert in this area. If it does actually have a habit of reverting to the typical (wild species) plant (here or elsewhere), then in those areas where the typical species seeds out and invades habitats the cultivar should not be sold and planted (especially if this is illegal!). However, it may not have habitat invasion cabability in every part of the continent.
I did some research online and discovered a site with a rating system (I think it was for Indiana) for various creeping/potentially invasive plants. Japanese Blood Grass was near the bottom but dwarf plumbago and Vinca minor-both of which I have--were at the top. This website also said that Blood grass was stoloniferous (as were the other two I mentioned.) Is this true?
This weekend I happened past a yard in North Vancouver that has a whole lawn of Japanese Blood Grass. I kid you not. It seemed to be bounded by driveway or sidewalk, public sidewalk, house, and I don't know what on the fourth side, and the whole property looked stuffed with it. I don't want to say it didn't look gorgeous, because it was late in the day and the sun was low, catching the red tips most impressively, but sheeesh... I'd have to revise my earlier comment and say this is obviously hardy in Zone 8. And yes, I'd call it stoloniferous.
Have seen it sold for years here, never picked up on the idea it was tender until seeing it described as such quite recently in one book.
The University College I teach at has some student housing with JBG covering a huge area. It isn't in a place I go regularly, but after reading your post, I think I may go have a look at it. As per the stoloniferous bit, to me it just seems unusual that it is, so thanks for your comment on that. It may be common amongst ornamental grasses for them to do so, but I don't have much experience with them (yet!), so thanks again for the comment.
A well prepared soil for Japanese bloodgrass could be contained and surrounded with the root barriers that are sold as panels, or by rolls, such as for bamboo. If another border plant was added, it could cover the upper edge of the panel. That grass performed well for me, and I may grow it again at this property, too.
Bamboo barriers are 24-36 inches deep. That's really deep for a small height grass, eh? I was thinking of a 12" root barrier, but the ones I have found push the roots down, which would be the wrong way!
