Paul

==>> these two statements are not consistent..

it is either a bog.. which requires bog plants ...

or it is a seasonal deluge.. and depending on the season .. may or may not require bog type plants ...

and we would have to know what kind of tree .. and how many hours of sun/shade.. to go much further ... and what is the native soil in that area ... [drainage]

and based on your neophyte learning curve.. are you sure your failure was water based only???? or could there have been other issues ???

i guess what i am inartfully trying to say.. is that you are beginning the premise with an assumption about the ambient water.. and i wonder about that assumption ... if you are not correct.. then we wont be of much help...

ken

Here are some natives that are happy at a wetland edge. I'm giving you shrubs as well as some herbaceous perennials. Be sure you know your soil pH and whether it fulfills the plants' requirements since I live in an area of acid soils, but I don't know your pH.

- Rhododendron viscosum (swamp azalea) has white to pink early summer flowers which are vanilla scented. This will only flower if it gets at least some sun.
- Clethra alnifolia (Sweet pepperbush or summersweet) has spikes of white to pink late summer flowers. Some of the selections of the species are better than others for impact: 'Ruby Spice' has pink flowers, 'Anne Bidwell' sports clusters of white spikes and 'Sixteen Candles' is compact with large white spikes. Clethra flowers better in more sun, but is tolerant of sun, shade, wet or dry and will flower at least some in all these conditions.
- Ilex verticillata (winterberry deciduous holly) has showstopping fall to early winter scarlet berries on bare branches, but needs at least half day sun to flower and berry well. 'Winter Red' holds the berries the longest, according to research I've read, and is the variety I grow, though is only now getting large enough to berry. Be sure to plant the appropriate male in an unobtrusive place in order to get berries.
- Caltha palustris (marsh marigold) has bright yellow spring flowers in wet areas, and the foliage will die back in summer if it's dry. It seems to do well in some shade since it grows and blooms largely before the trees leaf out.
- Osmunda cinnamonea & O. clatoniana (cinnamon & interrupted ferns) both provide statuesque foliage for shade. They tolerate wet soil, but are happy if the soil is normal moisture also.
- Osmunda regalis (royal fern) is a tall lacy wetland fern with beautiful clear yellow fall foliage and requires wet soil all the time. I've seen it in sun and shade.
- Veratrum viride (false hellebore) has large, pleated foliage that would make a good hosta substitute and needs to be in a wet area. Everywhere I know that this grows is in the shade. I've never seen it at a regular nursery, but you might find it at a wetland mitigation nursery or specialist nursery for wetland plants.
For late summer bloom, there are several large statuesque plants, including Eupatoriums and Veronias, but all need at least half day sun and are happiest in full sun.
- Eupatorium purpureum (now renamed by botanists as Eupatoriadelphus maculatus, common name joe pye weed) has clusters of mauvy purple fringy flowers in late summer.
- Eupatorium perfoliatum (boneset) has similar clusters of white flowers in August.
- Veronia has deeper purple flowers. Vernonia fasciculata (prairie ironweed) is tolerant of moist and dry conditions as is V. noveboracensis (New York ironweed.) There may be others local to you that work well.
- Iris versicolor (blueflag iris) is a native iris that I've seen blooming in full shade. It will bloom better in some sun. (As a side note, don't plant Iris pseudacorus, yellow flag, as it is an non-native that is invasive in wetlands.)

Side note on "bogs" and other wetlands since Ken added comments about this . . . Technically bogs are a year-round wet area with a low pH and virtually no flow, unlike the way this term is often used. They grow plants such as sphagnum moss, pitcher plants, and native cranberries. It is common around here to have seasonally flooded wetlands, either vernal pools which are flooded in spring but dry up in summer, or areas which flood after rainstorms for a few hours or days. Some wetland fringes are underwater in wet times but quite dry in low rain times. Any type of seasonally wet area tends to be difficult growing conditions as there are a limited number of plants which like being submerged at the beginning of the growing season but also are happy if they are bone dry in August.

There are several other factors:
1. There are trees everywhere. The area is shady.
2. The soil is different than my yard, it's black and mucky. Sometimes there's smell of decaying organic matter. Lots of worms though. The soil can get water logged.
3. Plants usually died off when the yard get submerged.

Paul

This is what I have planted in the area:

Ilex verticillata (with a pollinator)
clethra
itea
caltha palustris
chelone
bog rosemary
lobelia cardinalis
lobelia syphilitica
siberian, louisiana, and japanese iris
swamp azalea
hibiscus
ligularia
cephalanthus
cimicifuga
viburnum
cornus alba

Already in the bed before expansion were hostas, peonies, astilbes, bleeding hearts, and some kind of bluebells (these surprised me - I believe they are Spanish, which are bulbs, which I didn't think would survive the wetness).

There are also ferns, which I think were not planted but grow there naturally, as well as native asters, which do very well there.

Unfortunately the skunk cabbage, that nasty wild raspberry (I think that's what it is) and even poison ivy do well here too!

Some of these plants are experimental - the garden was expanded about two or three years ago and we tried a few things not knowing if it would be too wet or too shady. The ilex (for sun reasons) and the dogwood (for moisture reasons) are the two biggest "ifs" and so far so good, although the holly is not up to what I had hoped so far. We'll see.

Everything else is really doing quite well - itea, irises, ligularia, caltha and lobelia especially. And from the original planting the peonies and astilbes are doing very well.

Oh, and how could I forget? The two biggest things - two willows, salix hakuro nishiki. They LOVE it here. As a matter of fact I was looking at them last week and I'm beginning to nervously think about that (for me) four-letter word "prune". I kept seeing things like "don't overwater" in care instructions, but they are in the deepest part of the standing water and are thriving.

Hope this helps! This can be a really fun area to garden in if you work with it! (Well, maybe not fun to actually work in - have gotten shoes sucked right off my feet and stuck in the mud, lol) but the results can be beautiful!

Dee

and also.. after heavy rain.. could be under water.. for a few days ...

and that is what i call TEMPORARY water ...

dormant plants didnt care in spring .. nothing failed for such ... and nothing i planted was specific to seasonal damp ... and in fact.. most stuff did supremely

i am not sure you need 'special' plants for the area ...

and i am not sure there is enough water.. for those that REQUIRE [rather than tolerate] a lot of water ...

so your presumption of a lot of water.. may have been the failure of the plant .. or not.. who knows...

as you are learning.. you plant.. you experiment.. and what works works.. regardless of our theories...

ken