Raised Beds

Any thoughts, suggestions or warnings about building a raised bed under a locust tree? The trees roots are very close to the surface and are actually showing in the lawn in low areas. I don't want to take the chance of damaging the tree with the lawn mower. The idea was to build a bed about 8 foot square and 24 inches high with a cap rail for seating around the tree and filling the low spots in the lawn with soil and reseeding. Any advise would be appreciated! (please remember- you are talking to a novice) :)
Thanks!

That should work. I think the tree roots will eventually come up into the bed and have to be dealt with but at 24" deep it will take awhile. I have no idea what you could line the bed with to keep out the roots of a locust tree. Whether you use the topsoil available or go to farmers and stables to get materials for filling the bed will depend on your personal choice and ability to get the materials there. We have done about all of it and know that the topsoil here in central MO is black gumbo about everywhere until you go south about 25 miles or so and then you get into lots of rocks, quite a bit of plain old hardpan clay, and little else. Most people around here build raised beds with a mixture of top soil, leaves, stable/barnrabbit shed cleanings, and leftover decomposed silage or hay available at some farms. I still buy some professional quality potting soil and add to some of the beds and also get some of it from a botanical gardens where I sometimes do volunteer work. They throw away used potting soil regularly and add it to their own compost pile. I'm allowed to bring home anything they are throwing away the days I am there. Some towns/cities have compost piles they allow residents to access and there are also the sewage treatment plants which have sludge that can be used. Some of what you decide to use will be determined by what you plan to plant in the bed. You will need to balance the pH, watch for materials that either hold water too well or don't hold water well enough, balance the nutrients, etc..

I hope I have helped you and not scared you off with all this information.

The only problem I see is the 8 ft square part. You might not be able to reach the middle of the 8 ft part without walking in the bed. Maybe try two 4ft ones. Here are mine: They do make root barriers primarily used with sidewalks and stuff like that , but you could try that. I am not sure what the drainage would be like with these but you can look into it. I think with 24" of soil you might be fine for years with nothing. Landscape fabric might also work.

willismckenna has a good point. You need to be able to reach the center of the bed w/o steppin on it and compacting the soil.

I guess I wasn't thinking about how small a trunk a locust tree has. Yes, 8' would be kind of hard to maintain the center of. That would be close to a 3 1/2' reach in from each side if I am understaning you correctly. You are putting the bed around the trunk of the tree, aren't you? Or do mean off to one side of it?

I am hoping you just are meaning to put the bed in the root zone of the tree and not around the trunk. I would say skip the raised bed around the trunk if that was the plan. You will most likely kill the tree. Even a 3 1/2 ft reach is a long way to do anything like picking, pruning, staking, etc., although the 24" height will help increase your reaching ability.

Bill

Actually I was thinking of putting the planter around the trunk but was advised on the tree forum that that wasn't a good idea. And even though I have seen many planters with trees right in the middle of them, I don't want to take the chance of killing the tree. So hubby and I compromised with a few shade plants around the trunk and filling the low areas out in the lawn with an inch of compost and grass seed. He wasn't willing to give up the lawn to mulch as was suggested! :)
KD

If you go to Google and type in "raised flower bed around trees" you will find many designs and ideas.


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