Original question: I'm considering creating
wooden frames around very raised beds in my high tunnels for improved drainage and maximizing bed space. I'm wondering if anyone who has done this has any advice. Buying that much hemlock lumber looks expensive. Is it worth it? Any cost-cutting strategies?
I have had good success with that in the past. I recommend using recycled plastic lumber or pressure treated lumber. Or if you want real lumber I would find someone who mills black locust instead of hemlock. It will last way longer.
Also, to keep the side boards from bowing out I drive a high tunnel side wall stake deep into the ground every eight feet or so along the outsides of each bed.
if you are looking for good hemlock prices i would suggest connecting with my lumber guy Jordan, he is the best. Locayed in Ordford NH. Contact info below, hope your project goes well!
I would spend the money improving drainage around the perimeter and excluding water from entering the tunnel. Either with external grading or drainage inside along the perimeter(12” deep 4” perforated pipe with coarse sand on top) to catch water before it
moves across the tunnel.Even with raised beds if you have water moving in the aisles it creates a wet, humid environment.
Our heated greenhouses have raised beds made out of rough cut hemlock - 18" high, 1"x6" boards.
For us, with beds that high, we tie them together with rope through the bed, so they don't bow out when the soil freezes in the winter.
We also installed radiant heat pipes inside the beds, and that has been great for early tomatoes and early cucumbers.
We have replaced the boards over the years at least twice. Recently we have experimented with lining the inside of the beds with sheets of black plastic mulch. So far it seems to greatly cut down on how fast the lumber rots, as there is no contact between
the lumber and the soil.
Have considered the same here, and have started to in Tomato houses, but also realized (obvious) that w the raised beds walkways can consume 1/3 of potential growing space, not ideal in winter, but easier to harvest in. There also has to be some management
of the water/nutrients that flow out of the bottom of the beds into the walkways.
1" hemlock at .65 a foot for 8" boards is about .40 a running foot. Pretty inexpensive really as far as lumber goes, and safely biodegradable. I use predrilled 1/2 EMT stakes.
Hemlock is not better than pine unless it’s from an old growth forest, or so our local lumber guys tell me. And who wants to cut down old growth hemlock for raised beds? I’d go for pine…l
I have grown for many years, on heavy wet soil. Please give me a call if you would like to discuss wooden raised beds: cost vs. benefit. It is a rather nuanced issue that feels more appropriate to conversation that email…
Hope I can help by offering my experience,
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Definitely. Increased my space use efficiency by 33%, looks cleaner, and makes a clear demarcation between bed and alley which is a plus for employees always walking through beds.
Haven't done this in a high tunnel, but we used edged slabs, sawn side out, with stakes driven into the ground on the outside for raised veg. beds years ago. Minimal fasteners needed as the soil itself holds the slabs against the stakes. Happy with the design
at the time, and slabs were free. You could check with you local saw mill, or portable mill sawyer.