Author Topic: thin retaining walls for greenhouse instead of pots  (Read 753 times)

Daintree

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thin retaining walls for greenhouse instead of pots
« on: September 10, 2023, 12:59:19 PM »
I am on vacation and just went to Kew Gardens. Loved the palm house, and am toying with getting rid of the pots in my greenhouse,
Because of massive maple tree roots under the greenhouse, I can't even dig down a few inches. But I'm thinking of very large raised beds, maybe 15" high, and letting the trees in the greenhouse dig down into native soil and wiggle trhough the maple roots.
Any ideas for thin, sturdy raised bed walls? 4" wide cinderblocks and anchor them? Wood that won't rot or poison my plants? Thin poured concrete walls?
Hmmm...

Carolyn

NateTheGreat

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Re: thin retaining walls for greenhouse instead of pots
« Reply #1 on: September 10, 2023, 01:44:20 PM »
I think the maple roots would just grow up into your raised beds. I got some 7.5 gal fabric grow bags several years ago, and they're holding up well so far. If you put them up against one another, staggering the rows, they're almost like a 12" raised bed. Very little wasted space. That way you could still move plants around too. 

brian

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Re: thin retaining walls for greenhouse instead of pots
« Reply #2 on: September 10, 2023, 01:59:51 PM »
If you can find a reasonably priced 8-10mm polycarbonate panel they are quite sturdy and won't rot.   

I am curious why you want to switch from containers to raised beds.  I find containers really convenient to be able to inspect plant roots and change soil. 

Jaboticaba45

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Re: thin retaining walls for greenhouse instead of pots
« Reply #3 on: September 10, 2023, 02:00:24 PM »
You can do bottomless rootmakers like Mark and I.
Works really well as it's no dig either. Now maybe the maple roots will grow up though like mentioned. Could you take out the maple trees?
I have some decent sized trees about 20' from the greenhouse and I plant to cut them out this winter cause of shade issues.

Daintree

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Re: thin retaining walls for greenhouse instead of pots
« Reply #4 on: September 10, 2023, 03:15:02 PM »
If you can find a reasonably priced 8-10mm polycarbonate panel they are quite sturdy and won't rot.   

I am curious why you want to switch from containers to raised beds.  I find containers really convenient to be able to inspect plant roots and change soil.

I just thought it would look prettier, plus as I get older, it is harder to repot the bigger trees when they need it.

Daintree

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Re: thin retaining walls for greenhouse instead of pots
« Reply #5 on: September 10, 2023, 03:24:16 PM »
You can do bottomless rootmakers like Mark and I.
Works really well as it's no dig either. Now maybe the maple roots will grow up though like mentioned. Could you take out the maple trees?
I have some decent sized trees about 20' from the greenhouse and I plant to cut them out this winter cause of shade issues.
Yeah, the maple tree is 70 years old, shades the greenhouse in our hot cloudless summers, and houses all sorts of wildlife.  We did cut down 3 fir trees to put in the greenhouse, so I just don't have the heart to kill "Mabel". When the arborist says she's on the way out then we'll do it.
And yes, I guess the roots would grow up into any raised beds, and probably rootmaker pots, although the pots are a good option.  There is about 6 inches of bark on the floor that has been decomposing over the years, and I noticed Mabel's roots have come up through that.
Heavy sigh.

Carolyn

fruitnut1944

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Re: thin retaining walls for greenhouse instead of pots
« Reply #6 on: September 10, 2023, 09:44:40 PM »
I agree that maple roots will grow into the pots. So, how about trenching down about three feet between the maple and the greenhouse. Install a root barrier and refill the trench. That should get you quite a few years before the maple roots find their way back.

There are heavy duty sheets of root barrier sold online.

 

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