Looks like H. perforatum is the only one on the Colorado Noxious Weed list right now, Aloha.

Here's a link to the "official" list that also tells you which "category" the different ones are in!

Skybird

P.S. Click on the Scientific Name heading to get them it the right order to easily look it up.

Here is a link that might be useful: Colorado Noxious Weed Management Program

Skybird, what would we all do w/o you always coming to the rescue.

I'm nervous just having anything like the same name. How different is the noxious plant vs. mine? Will mine too soon be on that list?

The GW thread I included talked about hybrids etc. Can you explain the difference in the way the name is in comparison to another plant family. What is the genus.

I have a slope that is very sunny area and I need something for erosion control. I'd like not to have to water it much/any, but I'd like it to look nice. The St. John's Wort sounds like it would do all that.

Can't help you too much on this one, Aloha! Have never grown it or any of the Hypericums myself! Here's some kind of general info that may--or may not--help you make a decision!

First, if I'm following your "genus" question the way you mean it! Hypericum is the genus, and calycinum is the species. So the one on the Noxious Weed list is the same genus but a different species (H. perforatum). I can't tell you if the calycinum will ever be added to the list, but just because something is the same genus that's on the list doesn't mean it has the same "problems" as the particular species that's on the list.

For example, oxeye daisy is on the list, and it's on the B List! Oxeye daisy is Chrysanthemum leucanthemum, and "garden mums," genus Chrysanthemum are never gonna be on the list--guarantee it! Before it was reclassified, oxeye daisy used to go by genus Leucanthemum, species vulgare (yeah, that means "vulgar," or, actually, more like "common!"), but there are (were before they were reclassified too!) also lots of other Leucanthemums. For instance all the Shasta Daisies used to be classified as Leucanthemum x superbum but then were reclassified as Chrysanthemum maximum! (Actually I don't know if any of those have been REclassified back to their old genus/species again or not since I've been "out of the business" for over ten years now!) But, the point is, that there are a LOT of genus Chrysanthemum things, and the ONLY one on the Colorado Noxious Weed list is the oxeye daisy one! Oxeye daisy, by general appearance, looks just like the "other" Shasta daisies, but there is "something" genetically different in that species that makes it invasive enough to get it on the list! So the genus alone doesn't really tell you anything! I guess it's conceivable that a whole genus would be banned, but I suspect that's extremely unlikely. There are several different species of the same genus on the list for some things--but that still doesn't mean there's anything "wrong" with the other species in that genus--or that other species in that genus may be added to the list at some time--but it could happen! Just no way to know at all what may be determined to be a problem at some point in the future!

I LOVE Hypericum flowers, but I've never grown one--of any species, mostly because all the ones I ever came into contact with looked like they would spread a lot--as in, coming out of the holes in the bottom of gallon pots! Anytime I see something coming out of the holes in the bottom of pots I consider it a stop sign! Wish I had done that with the Zauschneria I'm now trying to get rid of! But with the one you're looking at, the spreading is actually desirable, so that wouldn't be a problem for you!

When I was at Paulino's we didn't sell calycinum, but carried a spreading one, H. reptans. Don't really remember much about it! We listed both of them in the "perennial bible" I carried with me for reference, and neither of them is listed as xeric! The notes I have after calycinum say: large flowers, aggressive, and semi-evergreen! I also looked both of them up on Kelly/Timberline's current list, and he doesn't show either as xeric either, so don't really know how well it will/would do without water! Hopefully there will be someone else around here who has actually grown it that can give you some advice on that. Since you got one I'd say plant it there and see how it goes this summer!

For the slope you're describing, any of the succulents would work and be very xeric. Have you looked at the Need help selecting a groundcover plant thread? I listed a few of the succulent things there, but there are lots more. If you decided to go that way you could mix things up a little to get some variety rather than all just one thing, but I don't know the exact situation, so maybe the "all one thing" would look and be better for your area. The Turkish Veronica, Veronica liwanensis, mentioned in that thread is also xeric and should work, and the Master of All Xeric Groundcovers, woolly thyme, would work too, but to me a great big patch of just that would be pretty boring!

If the Hypericum you got turns out to be xeric enough, and you like the overall appearance, it sounds pretty nice!

Wish I could give you some more specific info on it!

Skybird

Skybird, you have unconfused me :)

Your explanation of the genus and species helped a lot for this and other applications in the future. I'm really glad you have the Oxeye Daisy as an example being that it looks like other daisies. This St. John's Wort looks a lot like the noxious one. I don't anticipate having anyone from the state hassling me about it, but if I did, I have the information that mine is fine.

I still have several of the sedums you shared with me from the 2011 Spring swap. They are more then thriving! With the slope that I have, this plant comes very recommended for erosion.

The area currently has a 4' Austrian Pine and a newby Hawthorne and will also house a few shrubs along with some perennials plants. I'll likely toss in a boulder or 2 for good measure. Though I read where others have done an entire slope with this just SJW, I want to break it up. The SJW will be the filler.

When you google St. John's Wort there are plenty of articles about it being good for xeriscape. I couldn't find anything though from Colorado. Like you said plant it and see. Thanks again for all your help.

Here is a link that might be useful: St. John's Wort For Xeriscaping

Thanks, Aloha! I reread that AFTER I posted it, and started wondering if maybe I had made you even confuseder!!! Glad it made sense to you!

I'll be interested at the end of the summer to see how it's doing for you! The site you linked has "east coast info" and it suggests the use of St. John's Wort in a "general" way, without a species. I searched a little bit for Hypericum with xeric and didn't come up with much. Saw a couple references to "xeric" areas in Florida and went: HUH??? And that site also recommends "creeping lily turf" which is Liriope, and that, too, might work in the "xeric" areas in Florida (HUH???), but it wouldn't work AT ALL as a xeric plant out here. We didn't grow it and didn't have it regularly, but every now and then we'd buy some in since people would ask for it, and when we had it it didn't even look good in the pots out here. When you're googling for info, try to find .edu or .org sites for reliable info, and Extension sites from this end of the world are always good, but in my experience the "ehow" and "about" type sites have such generic info it often isn't very relevant out here.

To give yourself the best chance for it to work, water it VERY deeply over the summer, and gradually stretch it out longer and longer between the waterings. Watering on a slope is hard, so either do it in short periods with time between for the water to soak in, or, since you only have one plant for this year, lay a hose at the base of the plant on JUST BARELY a trickle and let it run for an hour, checking to be sure it's not running off, and if it is, turn it off for a while and then start it again. You need to get the deepest roots you possibly can before it goes dormant if it's gonna work. Broadleaf evergreen things out here are very prone to sunburn when they're dormant in winter. I hope it does work for you since you like it so much!

Wish you were able to come to the swap! I potted up a bunch more sedums and have some of the 'Lavender Ice" iceplant this time, and a couple 'White Nuggets', and maybe you could get a couple different things you didn't get last year. Oh, well! There is always the next swap!

Glad you're planning to put in a mix of things! All one thing can get really boring, and with a variety and with things changing all the time you'll have something to watch and be exited about!

Will be looking for your update later in the year,
Skybird

One reason for its "noxious" classification is that Hypericum (maybe just St. John's wort, maybe others) is attractive to livestock, and it has a chemical in it that causes photosensitivity ... so you get sheep and cows with horribly sunburned ears and noses. Those get infected, etc.