Use concrete pavers or cinder blocks for your raised bed frames if termites are a serious concern to you. The cinder blocks will likely be the least expensive option. They can be painted if you desire for aesthetic purposes. Expensive, but termite proof is the synthetic decking material. These typically aren't very thick and I have no idea how well they would resist bowing out if not reinforced.

You can also choose bug resistant wood such as pressure treated or cedar, but these aren't really termite proof, just less desirable than other wood.

If these beds will be well away from the home, I wouldn't worry about it personally.

Mulches are a double edged sword. They do great things for the soil/plants, but also can harbor pests. It's a call you have to make and again, some woods are less apetizing than others to termites, but none are termite proof AFAIK.

Termites are very active in my area so I went with cinderblocks. I didn't want to use treated wood around my food. Not the most attractive beds but by the time the mulch goes in and the plants grow over it doesn't look so bad. Also, I live where the clay is like concrete. We laid out the beds with cinderblocks and dug out 6-8 inches of clay and weeds then filled them back up with topsoil and Nature's Helper. Will add compost and leaves this fall to improve the soil but so far so good.

I have always used cinder blocks with great success, but the latest beds were in a place a bit tight and I went with 1 square foot red pavers (1 inch thick, 1.37 at Home Depot), planted halfway in the clay, to save 42 inches that would have been eaten by six rows of 8 inches wide cinder blocks. They also had 1 inch thick 8X16 red pavers at 0.98 each. You can plant the cinder block holes but it is not as tidy as a regular bed.

With the pavers, the new beds look good but it is more work to set them up, and they will take winter freezing less well. I also advised a friend to get cinder blocks and he found and implemented narrow cinder blocks (I think they are 4" instead of 8") which look better than regular cinder blocks.

I have a wood and a cinderblock garden. My husband put a wood bench thing to make it look nicer and give me a place to sit while looking at my garden. I posted link below with pics

Here is a link that might be useful: cinder block raised garden bed

i used galvanized metal roofing for my raised beds. Cheaper than cinder block and takes up less space. Check out the link for details on how i built the first one. The second bed was even easier-remembered we had some leftover 2x2 Trex posts so just screwed the panels to them with some metal screws. Works just fine ; ) The only caveat is that it can get a little warm around the edges, probably a great thing in the early spring but not so much by midsummer. There are ways to shade the sides if needed tho, so not a huge problem.

Here is a link that might be useful: Details here

yes corrugated roofing makes for a good simple bed construction doesn't need to be full width it can be cut down to 1/2 width, then take less to fill it.

many gardens over here just use galvanised star pickets for supports, and usually the tallest ones around 6', this then gives you extra height to put lattice on for the climbers.

3/4" hose cut down one side can be slipped over the edge to save cuts, tie it in place with cable ties or some galv' wire.

we've used what i know as clip lok roofing second hand it comes in 10" or 20" wide strips around the 6 or 5 meter mark in lenght, a bed 6 meters long and 1 meter wide all holds together with 4 stainless steel screws, no post supports needed. they where still going strong 8 years later. we have pic's on our site.

our current beds where hay bale beds the hay has all rotted now but the beds are holding their shape no worries. later if finances allow we'll use corrugated, need to consider we are getting older so higher beds mght be the go just filling them is the problem.

len

Here is a link that might be useful: lens garden page

Justaguy:

Well one thing for sure is I've heard that pressure treated wood is not good because it can leech IIRC arsnic into the soil or the whatever chemicals they used to make that wood bug/termite resistant.

I am aware that NOTHING is X-proof. Hell even so called 'bulletproof' vests are not bullet proof but only 'resistant' up to thier grading.

I have heard that cedar is naturally termite resistant however a quick look at the Home Depot pricings for cedar wood sent me into shock. I think it was something like $30 for a 2 x 4 x 10. That's canadian pricing mind you per single piece of timber where as I think it was pine or something less but real wood and not some plywood that was ~$4.50 for ~2 x 4 x 10.

I have heard/read online somewhere before that cedar lasts the longest while being bug resistant however that stick cost is holy tamolies. Now I've heard that using the cheapest timber invites bugs to chew it up and it won't last a season before it starts to fall apart on you.

Can I get some people here with experience on that cedar vs other wood and how long the wood stood up and the problems they faced? Oh I forgot but we have a hell of a lot of sod bugs or whatever you call those bugs that look like little armadillos the size of your pinky finger nail that if you flick them they will roll up into a ball and stay that way for like 30-60secs before opening up again. They have a semi-hard shell tho a human can squish them but I think small birds may avoid them for thier semi-armor.

If I go with cinder block what do I do to make sure the blocks don't fall over, over time due to earth shifting? I live on a hill but the area I'm using is graded but my side of the house sloped. If I remember correctly cinder blocks are hollow in the middle. So I fill with pea gravel to keep the weeds out? Can I still grow small herbs in the hollow areas?

I'm thinking I will need 2-3 cinder blocks high as if I want to grow tomatos thier roots are deeper or can I get away with 2 cinder blocks high? Can the roots still penetrate the clay soil if I loosen the bottom of the clay? I don't want to dig out all the clay soil as 1. I've no where to put it and 2. I've already got about 2-3cu ft of clay soil mounted up on the side of the house. Not to mention that extra cinder block means extra soil to top up.

I'm very lucky that our city provides free compost with thier greenbin program but the catch is you bring your own transport, bins, and shovels. Closer locations to compost depots are only on special events like 'enviromental' days. Last year I got like 1.5-2cu ft of compost with 2 car trips as the event was about 2 km away I could have faster turn around trips to get more. :)

Saves me money as I think my first fill in the growbed will need to be triple mix from a garden center by bulk which will cost like $150ish for about 3cu ft deleivered to the door.

Gardenlen:

I'm concerned about metals in the soil as well. I know wood would be the ideal natural solution but the termite thing is the only hold back for me. I'm not sure abou thte cinderblocks and tin roofing as well. My understanding is that tin is a metal and in the soil it can leech out possible metals IIRC.

What is the material composition of the cinder blocks? What makes up a cinderblock? Is there any leeching (no matter how minute) of chemicals that is harmful to humans?

Thanks.

Bump. I just got about 1cu yard of free compost from the city from thier enviromental day. Need some rapid replies to my previous questions because I need to get something in motion before next weekend as there is another free compost event locally and I need to free my containers first before going and rying to get about 2cu yd if I'm early enough.

Thanks in advance.

My first raised beds were of 1 inch by 12 inch pine. By four or five years they were disintegrated from the bottom, which isn't too bad given how cheap they were. When I replaced them I went with 2" x 6" cedar for various reasons. Not cheap, but I do hope it will last a long time. I only put in maybe one new bed a year so I can at least spread the expense out.

If you are looking for cheap but durable, go with cinderblocks. If price isn't as big a deal, go with BRICK! Bricks are NATURALLY occuring clay that has had sand added and baked. There are NO chemicals of any kind that can leach out, that wouldn't already be present in your soil!

As far as making sure that the blocks don't move, the easiest thing would be to fill the cinderblocks with your growing medium, and yes by all means PLANT in them! Why would you want to give up good growing space?!

If you are going with brick you could always mortar them together! They would then hold themselves together in the shape you desire, and you wouldn't have to worry about any shifting!

With the cinderblocks, if you bury them about 2 inches deep, they should hold their place pretty well. I wouldn't expect that they would shift very much.

As far as your current clay soil goes, I wouldn't remove it! Clay has a wealth of minerals readily available for your plants. The only issue is that it retains water TOO well, and has a tendancy to get very hard, IF/WHEN it finally dries out. In my own case, (I have a very clay soil as well) I have added a large amount of organic material to the soil. I would dig up (not out) the clay to loosen it, then add any organic material you can find (leaves, grass clippings, bags of humus, peat moss, etc.) and mix it in the bottom of the raised beds. Next I would add the clay you mentioned you have on the side of your house with compost that you seem to have access to frequently, and maybe throw a little vermiculite and peat moss as well. This will give your beds pretty nice drainage, while also having water retaining capabilities. Your clay soil has its downside, but it is also a great blessing! Pure clay is not great for growing, but a clay/humus mix is almost ideal! Btw, by adding the organics (pre-broken down) to the bottom layer of your soil, you will be welcoming worms to come up into your raised beds. (You can't get anything better for your soil than worms!)

Good luck, and I hope this helps. Remember, clay is not a BAD thing, it just needs to be managed properly!

eaglesgarden,

Ok, brick sounds good but cost is the thing. What about the make up and safety of cinderblock? How much weight are the cinderblocks? I'm thinking I'm going to be needing 2 x 3.8 cu. yards of compressed peat moss for my proposed 2yd x 1yd grow space times 2 as I plan for a green house in the middle and two grow beds on the side. In my last experience it seems you need like you need 1 bag of peat moss and a lot of back breaking shovel tilling to get about 1.5-2ft deep of mixed in peatmoss to lossen the base of the ground grade so that deep root crops can have drainage when you build up the raised bed.

I'm curious how fast do termites populate in a growing season? (~8 months) I may go with a cheap wooden raised bed while costs save up for woodless products for the season. Are deck screws advised?

I've heard that growing beans helps break up heavy clay soil as beans have a very large fiberous root structure. IS there anything else recommended for growing in clay soil?

I right now have the following hardening off in the sun:

-marigolds
-yellow & green bell peppers
-chili & jalepeno peppers
-roma, tiny tim, beef steak, sub-arctic tomatos
-romaine lettuce
-green onions
-nasturiums
-english cucumbers
-basil
-garlic
-cirlantro
-rosemary
-sage
-gai-lan (chinese kale)
-bak choi
-bush green beans (heat resistant)
-stevia

and a few more I can't remember.

Ok so I heard alfalfa is used to break up hardpan which I assume is hard soil. Anyone else know of any other crops that are clay friendly for breaking up the soil?

"pixiegirl asked,
I'm concerned about metals in the soil as well. I know wood would be the ideal natural solution but the termite thing is the only hold back for me."

sorry i lost track of the thread.

nothing is certain in this gardening world so what we do is use that which appears the lessor of all evils, no doubt roof metal treated with zinc will leech some zinc, how much may never be known, but then treated timber is the worst for leaching arsnic etc.,. and cinder blocks may contain fly ash from power stations?? our gardens now just over 3 years old are doing well having started life as bale gardens they have no formal edging and don't need it, may not look pretty but is functional.

part of that is we simply can't afford any edging whatsoever, but when we do it will be corrugated roofing, whether used or new will be decided at the time.

and as for the termites for a lot of us they are a fact of life, so long as you protect your house and buildings (better still build houses and buildings that are termite resistant) then having them in the garden is no worry they too help with the break down or organic material. we've had a lot of gardens around our part of the state and to date i have never observed temites in the gardens though i have no doubt they are there.

len

Here is a link that might be useful: lens garden page

I originally determined that I would use cement blocks (avoiding the Fly Ash toxicity of cinder blocks). However, I am now reading that even cement can have Fly Ash in it. Ugh...