I've never seen anything like this. How does it work with plants? Do you fill that whole thing up with soil to the top? Half way?

It reminds me of the perimeter kill zone at a penitentiary where the SUVs and dobermans patrol.

I think lining the inside with plastic is effective to help preserve the wood on your raised bed. With no measurements given it is difficult to comment on the basic construction. Al

It is a good idea to help keep moisture in the planter. Those types of raised bed can get very dry very quickly if you live in an arid environment.

I'm seeing a much bigger problem though. It looks like you didn't treat the cut ends of the pressure treated lumber. They'll just rot from the inside out that way.

Is there such thing as a plant/soil friendly sealant/protectant that can be applied to the wood planters and containers Something non toxic that can prolong the life of the wood?

Being that your in Ca. your planter box should last you a few years before the moisture builds up and starts to cause you some problems due to the lack of flowing air.

oxboy, it depends on how friendly you want it. The current Copper ones aren't that bad. The safest and most effective non-metal based treatment is probably acetalated.

Welll, It is not just the wet/moist soil that you are concerned with. The moisture (from air, rain, condensation) trapped under the plastic is just as much harmful to the wood. I would remove the exposed plastic( use a utility knife).

BTW: The PT wood will have enough preservative against rotting for a long time. I use cedar lumber which also more durable than untreated pine.

Thanks everyone for your replies.

@ NIL13 - thanks for your comment on the exposed, cut PT. There is no soil at that level and I am putting a top cap on the planter so I think I'll be ok.

Here is photo of the planter populated with ficus.

Cap is excellent idea - I had build something similar (as tall as yours, just not so long) few years ago. It worked great, but I didn't put cap on immediately and water was getting into the wood and was sitting on top. If you could slope it few degrees toward outside to drain fast, even better...sorry for 'lecturing', you probably know that already.

Rina

This post was edited by rina_ on Mon, Mar 10, 14 at 16:55

I built some beds for my brother last season, and we lined them the same way...to keep chemicals out of the soil. We do need to add a cap, still.

Josh

Josh, yours look like 'better' wood, is it cedar? or?
Maybe because mine were that tall, I found water sitting on top for too long and then running down the rest of the boards. And, forgot to mention, I used 2x4 - so much thicker. I did have some extra stakes/supports just like in uncle's photo, that had exposed cuts.
Cap also made it look very finished, I was also using in front right by the driveway.
Rina

Rina,
that's just the "red" pressure treated color, made to look like better wood. The wood was 2X12 pressure treated.

Josh

Wood generally in southern california is damaged faster by uv rays than by rot because it's so sunny and dry here. you don't usually see a planter of that type made from wood because wood doesn't last all that long, compared to say masonry.

I'd be more concerned about what you planted in there. Those ficus are genetically pre-determined to want to be a 50 foot tree with a root system to match. They are going to want to bust out of there pretty quick, even if you keep them cut back.

If your planter faces south the soil temps may get too high. In the dark ages we coated the wood inside planters exposed to moisture with asphalt. It was both organic and eventually, biodegradable. Plastic tends to encourage condensation between the plastic and the wood unless it's glued directly to the wood.

Did that at the cottage years ago. Took 15+ years for some of the 4x4's to show enough signs of rot to replace sections of them. Used heavy plastic to line. Recently had a 5' concrete retaining wall dug down to footing as water was escaping and eroding the front lawn. They used water proofing membrane that has nubbins on it to stand off of the wall. Am embarking on doing a raised planter and will use the same material. Will allow enough of an airspace hopefully to avoid replacing any wood for years to come. Always something new or something new to learn.

I have just made a pine wood box planter, very basic I must say as its my first one. I want to plant veg and herbs and I'm not sure if I should cover the wood in plastic or paint / varnish it to protect it from soil and water. Bear in mind I'm an expat in Addis Ababa, Ethiopia and I have to make do - I do not have a range of organic products to choose from. Any ideas would be greatly appreciated. The wood is untreated, not dried and its already splitting in places.

A better choice in wood would have been cedar or redwood. The pine will rot out quickly.

I don't have a choice, unfortunately. I just need it to last 3 or 4 years at most. How long do you think it wall take to rot?

It will likely rot in 1-2 years. Even if you were to line it with plastic, there will be still be plenty of moisture and perhaps 'sweating' between plastic & wood. And you need some drainage - so any holes in the plastic will let water leaking and get to wood. Without drainage (in plastic) you may have muddy soil. So if you can think of it as a very temporary set up that you may have use of for only a season or two, it will work as is.
Perhaps painting it with some kind of water repelling paint would help? - but you should probably paint all surfaces of wood that may be difficult to reach now since it is assembled.
If you can get wood easily, just use as is and make new one as needed.
Pallets are usually made from wood that is more rot resistant, can you get some in the location you are?
Rina

Hi Rina. If I could get 2 years out of it that would be fine. So do you think I shouldn't bother with the plastic?
I can see if I can get water repelling paint but the concern is that most of the stuff comes from China and its the cheap Chinese products not the better quality ones, so the chances of bad chemicals is high. Probably best not to paint with that stuff.
Maybe some sort of bees wax or candle wax? Any thoughts on that?
Pallets are a possibility. I recently had something air freighted in and I asked for the pallet.
Cheers,
Tanya

Tanya
I, personally, wouldn't. But it is up to you and what resources you have. If the wood is plentiful and inexpensive (like free:-), then it is easy to be replaced and you don't need to go to extra expense of painting etc. - as I mentioned all the exposed surface would need to be painted/waxed and you really can't get there since it is assembled.

Rina

Many thanks Rina.
The wood is not free but inexpensive so I can live with replacing it every year or so.

Regards,

Tanya

@unclegarage, how wide is your planter with Ficus Nitida? I am planning something similar, but using concrete instead of wood. Wondering how narrow of a planter will work for the ficus.

Thank you!

I saw a video that recommended roofing cement as a liner. It makes sense. Wood wouldn’t rot and the plastic liner wouldn’t deteriorate. Just would need to have a bottom on the planter box and make a few holes for drainage.

Most roofing cement has caustic chemicals that can leach into the soil and be in turn absorbed by your plants. Also, to apply such cement you need to use a reinforcement mesh to keep cement from cracking and failing. This can be laborious and very messy. The best liner is to use a polyethylene plastic- same material used for milk containers and such a plastic that does not leach harmful chemicals. We use such a plastic, it is thick and reinforced. The plastic we use and suggest you use is a commercial pond liner material. It's costly, but it works and when we install it in our planters we feel quite confident that our planters will last for years and years.....

Regular cement can also leach into the planter, changing the pH of the soil over time. (There have been claims that it will leach calcium into the soil without changing pH, but if you can explain that one to me, I'll give ye a pretty for obvious reasons).

Simply allowing the cement to cure fully and then sealing it with any good acrylic paint, epoxy paint, or plastic covering is fine and stops the problem.

Fun fact: You can purchase molds online (and in stores) to make your own concrete and/or resin pots. While not cheap for larger pots, you then have the option to cheaply produce as many of that pot as you wish (or not so cheaply in the case of resin) and be as creative as you wish with adornment, coloration, and paint job. They're most common for smaller succulent pots, but I've seen them for large pots as well.

Most will make a pot without a bottom hole, but it can be easily added with any power drill and bit of sufficient diameter.

Regular cement is an enormous energy user to produce. To make cement it requires more energy to make it than steel. Wood by far produces less carbon to produce. You also promoting an industry that is a renewable. Trees are replanted here in the Pacific Northwest after harvest. Trees absorb carbon dioxide and store it. The trick is to use the wood material wisely. Building a container without a liner is like wasting 30 to 40 years of tree growth. One could use roofing cement (tar made from petroleum distillation), but as previous stated it leaches unwanted chemicals in the soil, there are some that are made from other materials, but these are not easy to apply.

Wood is by far the cheapest used material; though, It is apparent that big box stores and many smaller identities are only concerned in making profits. They certainly do not care about the environment, this goes onward down to the consumer.... they all want the cheapest Chinese made items just so they can have the highest profit margins and lowest price. Most consumers are purchasing to keep up with Joe Schmoe or the Jones' family. These products are built with basically slave waged labor and packed flat boxes, shipped thousand of miles ( even in many cases the wood, logs are shipped thousand of miles producing tons of carbon to transport), last they are packed with inadequate/substandard fasteners- You might as well throw these planters away for these planters will make it only through one or two growing season...

We must treat the environment wisely, if we are going to survive. We must buy things that have utility/longevity, buy less than more, buy things that have the least carbon using foot print and buy things we absolutely need.

"Roof cement is comprised of a variety of different materials: asphalt, refined mineral spirits, non-asbestos reinforcing fibers, and plasticizers."

I think we're going to have to agree to disagree on the environmental wisdom of using this stuff for pots; I'd rather avoid it at any cost and accept the energy usage of concrete instead.

Wood's great, though of course you do have to account for the pressure sealing chemicals and energy required to process it, and even so, I'd recommend a good second sealing (or, topically, a lining) on the inside of the pot. It'll still decay over time, or age visibly without protection, which is a consideration.

One doesn't have to use any chemicals in wood... Yes, pressure treated wood is caustic. We are talking about regular wood which can be preserved with plant oils..... Concrete is extremely heavy and is cumbersome to use. This is not the material for the average household inhabitant that lives either in a rented house, apartment or condominium. Simply stated, not everyone has gardens that can support heavy vessels, nor does the average home have a place to assemble/form and pour concrete/cement. Last a form alone is going to require wood or steel that could have easily made two or more planters...

The forms are made of silicone, so that's not really an issue, if that's what you're talking about. Although concrete, over time, becomes extremely light. It's a complete misnomer that it's heavy. When new, absolutely. Once fully cured, I can lift a fairly large piece with a single hand.

Personally, I mostly use ceramics or clays that--in some cases--I've made myself and glazed myself. Or painted myself for that matter. :-) Sometimes very durable plastics, although I'm not adding to my plastics any longer (I'm not actively getting rid of them, but not adding to them any longer).

Technically, neither ceramic nor clay require lining or coatings, but I tend to do so anyway, at least with a coat of heavy-duty acrylic paint. Transparent acrylic base, if nothing else.

Morpheuspa, this discussion is not about making tiny pots, please note its about large "real" planters that are needed to grow large plants? How are you going to make a form out of silicone to make a planter that say 2' x 4'. 3' x 3' or any real sizable dimension. Yes, you can make your small scale pots out of concrete and ceramic....