Raised beds and termites - how to build correctly?

Based on the reading I've done regarding gardening in the Houston area, raised beds seem the easiest way to go here, since the soil is thick and wet and drains poorly.

I want to build them along the perimeter of the back yard, and along one side of the house in the front. However, I have a question about termites. We've had previous infestations at our house and the inspector said to keep dirt and wood away from the foundation.

Okay, I get that. But how do I build a raised bed against the fence, or the house, without inviting termites? If I put a back wall on the raised bed (i.e., up against the house or fence) made of plastic or stone or something, would that block them? Or, do I have to pull the entire thing a certain distance away from the house and leave an open trench back there (which seems like it would look horrible).

I can't seem to find any information regarding this topic online anywhere, whether I search for termite information or raised bed information. But I see raised beds up against houses and fences all the time, so clearly there is a way.

Any suggestions?

Oh PS - same question with regards to trellises up against the house.

If I put weed cloth or something down underneath the beds, would that keep the termites out?

This message was edited Jul 27, 2006 3:15 PM

Digi, I was wondering that too. I couldn't come up with a solution so I have no raised beds by the fence or house. I hope someone has an idea. My trellises are made of copper so they can go by the house.

I just like to keep stuff away from the house so I can check the foundation for fireants and termites without any trouble. Also, in some places there are regulations about hardscaping within a certain distance of a fence. I'm in the process of putting three raised beds along my back fence, and am leaving enough space between the beds and the fence to lug the wheelbarrow. I will probably plant beans against the fence itself come spring. Don't think "open trench" -- think "path." And if you have enough room, maybe plant shrubs or native grass/sedge along the fence and bring the raised beds more into the center.

Just babbling. Hope it helps!

I guess maybe what I'll have to do is go talk to a landscape architect. Or, I wonder if my extension office could help with this? I just think it's odd that I can't find any info on this online - termites are everywhere and raised beds are everywhere, I'd think this would be a common question!

If I find anything out, I'll be sure to post for you, fly_girl!

It partly depends on the kind of termites in your area. If Houston is like NOLA, you get the kind that build mud tunnels from the nest into the area where they feed. Beds that are well away from the house, with treated lumber, should not be a big problem. If you get the kind we have in CO, the termites live ina big nest underground, and travel up to 20' to the area where they are feeding. BUT, they have to return to the nest every 48 hours. Treating the foundation of your house, and keeping all wood (chips, timbers) 20' away appears to be the only solution there.

Guess which kind we are trying to eradicate here? Guess how many linear feet of timber flowerbed edging has to be removed in the next 12 months. Oh Joy.

I think we have the mud tunnel kind. The termite inspector said that as long as we kept wood products and dirt at least a few inches away from the house, it should be okay, but I remember him mentioning the mud tunnels, too.

Another issue is drainage. We get rain in big dumps and so the ground gets really soggy. I noticed during this last storm that we've got several areas of standing water around the yard. So, maybe instead of "open trenches" along the house, I'll put in french drains! That would solve both problems at once!

Yes. French drains are your friends!

Whenever I make a raised bed, I use rock for the edge. BIG rocks (up to 2' diameter) on the outside, filled in with small rubble between rock wall and dirt. If the wall is in a place that needs directed drainage to prevent erosion, I put a 3" layer of fine rubble UNDER the large rocks, with a slight slope to direct the water away. This has stood up under some heavy rains /flash flood conditions recently.

We tore out the old landscape timbers that were used to build beds around the front and side of our home. I wouldn't call them "raised" beds since they only used one layer, and it had sunk as the timbers rotted. And when we lifted their remains, they were - of course - termite-infested. Those things got hauled to the landfill the same day they were excavated.

Our home is under a termite contract, so it gets an annual inspection and treatment anyway, but why keep the critters that close to you?.

When we re-did the beds, we used concrete landscape blocks and I use pine straw instead of wood mulch in those beds. The plants are a good distance (a couple feet at least) from the house.