Gardening in the Swamp!

Help! Iol I was sooo excited with my backyard when we recently purchased our home. I imagined all these gardens I was going to plant, despite the four trees (2 oaks, river birch and cypress). Well, now that I have been around here for a while and started really playing in the dirt back there, I realize its not so great. :( The back part of the yard that gets the most sun is like a swamp! What else could I have expected living in southeast LA? Duh! lol I have realized that I will need to do raised beds and am fine with that. My question is - should I do something to amend the "base" soil and if so what? I have thought about getting a truck full of sand or possibly sand and mud but am unsure if that is the right thing to do. And if I do that, should the ground be tilled? Will it hurt the tree roots if tilling it is going to cut up the roots? Trying to dig into the ground is difficult with all of the roots! Add what I am sure is several families of moles (and I thought they were crawfish mounds!) to the water and roots and I am ready to sell my house! LOL Since that's not really an option, what do I do? Any suggestions? Thanks!
Em.

If you're going to build raised beds I wouldn't waste my time with amending what's underneath. But you should be aware that it can be tricky doing raised beds around trees--some trees may do OK with their roots being covered up with more soil, but some trees don't like that and it could kill them eventually. Unfortunately I don't know which trees are OK with that sort of treatment so personally I always avoid piling soil over a tree's root zone.

The other thing to be careful of is when you raise things up in that part of the yard, where is the water going to go...make sure your house/foundation is not the new low spot!

A couple other things you could consider are 1) learn to love your swamp...find plants that like to grow in that sort of environment and work with what you have, or 2) have a drainage system installed to take away the excess moisture, then you plant in the area without having to worry about raised beds that might kill your trees, etc.

ecrane - you are such a sweetheart! you are always around helping ppl out. I read through so many forums each day and always see you offering advice and help. I for one appreciate how you willingly and generously offer assistance!

I wasn't originally going to amend the soil. But Monday I dug out a section by the back fence (no tree roots here) for some sunflowers. I enclosed it with 4 x 4 pieces. Well we had a bad rain Monday night and yesterday there was a river next to the 4x4. It didn't go into the bed but "flowed" right in front of it. That got me to thinking that maybe I should do something about the base soil.

The area where I want to do the veggie garden is about 5' from the river birch. There are no exposed roots in the area. You talked about the root zone. Does that mean I need to find out how far the roots generally grow out - even underground, and not plant over that area? Oh Lord I wont be able to plant anywhere in the yard LOL

Unfortunately, a drainage system is not an option right now, but def in the future. I will do some more research. Thanks again for your assistance!
Em.

Hopefully someone else will know if river birches are OK with having dirt piled over their roots--I really don't know. But if they are sensitive to that, their roots go out a lot farther than 5 feet, so I wouldn't feel comfortable putting something that close. I see that you're a subscriber, so I'd actually recommend you head over to the Trees & Shrubs forum and ask there whether river birches can tolerate having dirt piled over their roots or not.

if they can take their roots sitting in water, i don't think a small layer of soil or amendments is gonna do much.

I'm always finding plants that want to grow in swamps but all I have is a small pond! If you think that you want to try Ecrane's advice #1, you might try Louisiana irises which would love the area (hence the name!) and you wouldn't have to do anything.

There are also native azaleas like Piedmont and the Swamp azalea that love swampy conditions. Taro or elephant ears love it. I enjoy Illistrus (Illustris?).

There's also the Swamp Rose for sale at the Antique Rose Emporium. It's a once bloomer, but once bloomers are often really healthy and don't require any special care. I bet the Peggy Martin rose would work there too. If it can survive being under 20' of salt water, it can probably live in a swamp!

I rooted a bunch of my abutilons and mentioned to my neighbor that I was going to plant them in the sometimes swampy easement behind my house. He's an expert and he said they would love all that water. I've just planted them and they seem very happy even sitting in water.

One other thought, a friend of my parent's in north Houston had a swampy area. They planted some type of cedar and it dried it right up. At least I think it was a cedar? Someone who knows more about that will have to share with you, but I bet there are other water hogs that could help dry up the area for you.

I have a few more water hogs. I went out to my pond and two plants that I originally grew outside my pond have decided to grow in it instead - mint and creeping jenny. They like being waterlogged and so do my brugmansias. In fact, my shredded white brugmansia wanted so much water that I put it in a pot with no drainage. It liked that just fine. The pink one that's growing in the ground has a branch that has dipped down into the water and it's fine with that. My pink bananas like lots of water too. I'll shut up now since you probably want to grow nonswamp loving things!

Elphaba - those are great ideas. I am having to accept the fact that I just don't seem able to do what I originally wanted to do. The back yard also has a bald cypress, a live oak, as well as another oak I haven't identified yet. I read about the Peggy Martin rose. Can you believe how that survived?! Amazing. That water was nothing nice! I do have some mint but I put it in a container since it can be so invasive. I did go to the tree and shrub forum and was told that I should not plant over the root zone of the birch. The root zone extends out as far as the tree is tall. That tree is at least 25' tall! If thats the case and I can't plant in the root zone of any of the trees I can hang up thinking about a veggie garden or any garden at all for that matter! I am soo disappointed. And to think one of the things I liked about this house was all of the trees! I cant even think about cutting down a tree because there are city rules that prohibit it. You have to get special permission and permits, etc. The parish lost so many trees to Katrina they now dont want any cut down. Where's the chocolate??? I am depressed! LOL

They always say that about trees, but everyone plants under them and they usually do fine. Big trees are such a joy if you love birds and wildlife. I would try planting under it before I would cut it down. The previous owner of this house put raised beds (just raised by piling dirt not formally with lumber) under my oak, sweet gum, ash, and a sycamore. They're all fine. I didn't do raised beds but I did plant under a water oak and a willow oak and they're both fine too. I would be as nice as you can to the poor trees, but you have to be able to enjoy your garden! And chocolate is ALWAYS a good idea!

I doubt very much that a raised bed would bother your trees. You might have issues with keeping the trees from taking the nutrients, but those are established trees. I doubt you can do much to damage their root system. Have you thought about adding a rain garden to that area? It sounds ideal.

epb, i have planted plants around trees. some of my large trees have roots that extend way past the drip lines. I just used my hand mattock (chopper) and cut away the tree roots and planted. I didn't think plants liked being planted so close and in the root zone of trees, but have found that that isn't true. I planted about 10 china boy and girl hollies. I just knew the ones i planted under the silver maple and large pine tree wouldn't make it and be left dry. The darndest thing is is that they are the only ones surviving, the others all died on me. chopping the roots of the trees to plant would suffer far less damage than the ball and burlap trees that they sever most of the roots on. one source said they only get 5% of a trees roots when they b&b.

My concern was about building a raised bed over the tree's root system. Planting things around trees without raising the soil level significantly will not damage the majority of trees--the trouble you'll run into is that sometimes the tree will take most of the water and nutrients so the plants you plant under it won't do as well as if they were somewhere else.

As far as veggies go...is there even enough sun there to grow veggies if you could do your raised bed? Most veggies need a lot of sun (and nutrients) so under a tree is not going to be a great place for that anyway.

Thanks for everyone's ideas and concerns. After much agonizing, talking with several local gardeners and doing lots more research, I decided to go ahead and do the raised garden. The tree is well established and I actually measured (with a tape measure) how far away it is and its 8 1/2 feet from the tree (I have no sense of measurements obviously!). The bed will be 4 x 6. That spot is in the sunniest part of the whole yard and does get good full sun all day. I'm looking into putting fine mesh wire under the bed to try to deter the moles from digging into it. Any thoughts on that?

Elphaba I loved all of your suggestions and doc's about a rain garden. I have a spot towards the middle of the yard that is lower and has a wooden swing frame in it that I hang baskets from. A lot of water drains there and it stays wet long after the rest has dried up some. I think I will use your suggestions and do something like a rain garden there. But that is a project for another day. I already have too many in the works!

Again, thanks for all of your help. It is greatly appreciated!
Em.
passing the chocolate to Elphaba :)

Em, look up my article on rain gardens under my nick. I included several sites that give loads of information on how to and what to plant in these remarkable gardens. Naturally, I would love these. I have mostly full sun all the time and little shade, although another big tree planting is in the planning stages.........LOL Not a wet spot in sight anywhere...