[OptaGreen]

I am looking for suggestions on how to contain some aggressively spreading marsh/bog plant materials; i.e. cyperus, rush, iris, etc. I am putting together some ideas for a small "pond" at the entry to a riverbound subdivision. The "pond" is about 35x35. There are already some existing trees, cypress, willow and such, planted not so close to the pond's edge, so the idea is to bring some plant material to the edge. I am not looking to overpower the pond with materials, however. I have read several times that these plants should be planted in a "container" but am not sure what type of container. An empty plant container? A solid container? Any other plant suggestions would also be appreciated. Also, the pond has an inlet/outlet to/from a freshwater source. (if you consider swamp, freshwater)

[FungusMudGrub]

Usually water plants are in containers if submerged in an artificial pond. I don't think I would bother to use any kind of container beside a natural pond. Aggresive plants will just overtop the container and root themselves beside it and go, go, go. Maybe you could bury a barrier around the whole planting, instead.

[phototropic1]

Of the plants that you've listed, we've had the most trouble with Iris pseudoacorus. We grow it in pots slightly submerged in the water, but as detritus builds up near the rim, it seems to want to climb out. Every so often (once a year or every other year) we thin them out. Take note that weeds will also grow in these pots, so that can be a chore. Juncus does spread, but not to the point of being a problem. We don't bother using pots with these as they don't run with rhizomes like Iris does. Most of the Juncus seedlings that have appeared have been welcome and when not, are easy to pull. I don't have enough experience with Cyperus to really comment thoroughly. We do have some in a large pot within a fountain. After 3 years, the clump is showing little sign of wanting to migrate. Maybe others can give you better feedback on this one.
As for other plants to consider.....whew, I'll have to narrow down my list of favorites. By the way, all of these will thrive in your area, but will NOT be invasive like some others might be.

Itea virginica- virginia willow
Hymenocallis caroliniana- Spider lily
Osmunda cinnamonea- Cinnamon fern
Osmunda regalis- Royal fern
Lobelia cardinalis- Cardinal flower
Acorus sp. - Sweet Flag (maybe the one exception to not spreading. The clumps will grow quite large, but can easily be divided. And that foliage, ah, it smells so good!)
Saururus cernuus- Lizard's Tail (okay, this one spreads too, but it's really cool. Much more of a threat than Acorus)
Cephalanthus occidentalis- buttonbush
Clethra alnifolia- Sweetshrub

I could keep on going, but I'll stop here. If you want more info on any of these, let me know. I'd be glad to help. I love these wetland plants.

Whatever you do, stay away from Elephant Ears!!!

[Dale Wiley]

In your zone, I really doubt if you will be able to contain ANY of the plant's you mention. The nature way of wet land, and bog materials is to spread like that.

Juncus seeds will establish about any where, and over the course of a couple of years, establish quite well. Cyprus will do that same, we had some we threw out of a failed greenhouse last Feb, and also dumped the bed water out. That material ran about 150 feet and established a nice stand of cyprus in a stock plant area.

I am going to let it be and see how it does like that in zone 8.

A marginal planting like you describe should be lightly planted with mature plants, and then let nature take its course. Trying to recreate nature in less time than it occurs naturally, will only increase your problems down the road.

We sell a lot of marginals late in the season, for failed plantings in bio swales and remediation areas. They try and establish with plugs or bare root, and get a less than 30% survival rate, and then come looking for mature plants later on.