'How Does Your Garden Grow' thread - raised beds

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The discussion revolves around building raised garden beds primarily for vegetable gardening, considering factors like dimensions, materials, and stability. The proposed size is 4'x18", with a focus on waist-height for accessibility. Key concerns include whether to enclose the beds, drainage solutions, and the potential for critters to inhabit the space underneath. Participants suggest using untreated wood like cedar or redwood to avoid toxins and recommend landscaping fabric for lining. The conversation also touches on effective watering systems and pest management strategies to enhance gardening success.
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I was going to post this in the HDYGG thread but it's locked.

I am planning to build raised beds for gardering, mostly due to my Everlovin's diminishing ability to garden at ground-level. It sounds like it'll be mostly veggies. Zucchini, carrots, onions, tomatoes, basil, lettuce, beans, peas, etc.

I'm thinkin' 4'x18" would be about right. Not sure about height but shouldn't be hard to optimize it. Ill probably make the out of 4x4s and fenceboards. Prolly add trellises (trellii?) for beans.

Looks like we've got space for as many as eight all at waist-height. But they've only got two feet between them. Not sure that's enough. May have to put my foot down and cut back on numbers.

I don't really know anything about raised beds and want to understand the major factors. Mostly what I'm not sure about is:

What do you put underneath them? Are they open or enclosed? If they're enclosed I'm worrried about critters making homes in the space. Or does the dirt go right down to the ground? That's a lot of dirt!

But if they're just on stilts, how deep should the beds be? 12"? 18"? 24"? And I guess I've got to stabilize them somehow since they'll be top-heavy. Stakes, or concrete footer blocks. Ugh. Not looking forward to that. Concrete footers will be very awkward in that cramped space. Two foot aisles will become 1.5 foot aisles...

Does one line the beds with something? Do I have to worry about drainage? I wouldn't want a liner like poly - how would the water drain? Do I fill the bottom with rocks, like I do with my potted plants?

These raised beds won't do well in the winter, right? They'll freeze solid. So probably annuals only I guess?

Anything else I need to consider?
 
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*sigh* Belay much of that. I misunderstood the assignment.

Apparently they don't need to be waist high - 18" 24" high is sufficient.

So stability won't be an issue, nor will whether they are open or closed underneath, since they will be sitting right on the ground I guess.

And I guess what I line them with is landscaping fabric?
 
DaveC426913 said:
I was going to post this in the HDYGG thread but it's locked.

I am planning to build raised beds for gardering, mostly due to my Everlovin's diminishing ability to garden at ground-level. It sounds like it'll be mostly veggies. Zucchini, carrots, onions, tomatoes, basil, lettuce, beans, peas, etc.

I'm thinkin' 4'x18" would be about right. Not sure about height but shouldn't be hard to optimize it. Ill probably make the out of 4x4s and fenceboards. Prolly add trellises (trellii?) for beans.

Looks like we've got space for as many as eight all at waist-height. But they've only got two feet between them. Not sure that's enough. May have to put my foot down and cut back on numbers.

I don't really know anything about raised beds and want to understand the major factors. Mostly what I'm not sure about is:

What do you put underneath them? Are they open or enclosed? If they're enclosed I'm worrried about critters making homes in the space. Or does the dirt go right down to the ground? That's a lot of dirt!

But if they're just on stilts, how deep should the beds be? 12"? 18"? 24"? And I guess I've got to stabilize them somehow since they'll be top-heavy. Stakes, or concrete footer blocks. Ugh. Not looking forward to that. Concrete footers will be very awkward in that cramped space. Two foot aisles will become 1.5 foot aisles...

Does one line the beds with something? Do I have to worry about drainage? I wouldn't want a liner like poly - how would the water drain? Do I fill the bottom with rocks, like I do with my potted plants?

These raised beds won't do well in the winter, right? They'll freeze solid. So probably annuals only I guess?

Anything else I need to consider?
Watering systems. Last year I grew tomatoes in a few big pots. It worked out perfectly with a manually refilled watering system in a 5 Gal bucket
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https://www.blumat.com/en

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A soil monitor connected to the house automation system.
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The height to comfortably sit on is good.
Reaching about 18" from one side is reasonable, but you have to sides you can reach from.

I had mine sitting open bottomed on the Nothing between the dirt and wood sides. They lasted >8 years.

The carrots, onions (and relatives), and potatoes could survive the winter (in Eugene, Oregon) if left in th ground.Bushes like blueberries would also.

I used a cranked timer for garden hoses to control the water's (~10 min/day) delivery via a cheap garden sprayer system to the plants.

If you have insect or slug pests pesting your plants, set up a place for wasps to set-up a nest. Most ares have wasps that will predate on the pests around their nest. I used an old aquarium on end. Kept them out of the rain but was open for their easy access. The aquarium made observing them easy. Wasps that go after these insect pests won't bother you unless you mess with their nest. When I did this, I had no problem with the insect pests.
 
Active gardening provides a subject for discussion that enhances social interaction. Raised beds that work well with wheelchairs are a real bonus because they encourage physical exercise and regular outdoors activity in those who might otherwise become moribund.
 
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I have my mobile brain seat for the garden. Still too early to plant tomatoes here. Frost warning for this week.
 
Thanks guys! This is super helpful.

How do I build the frames without rotting the lumber in contact with the ground?

Is it OK to build them out of pressure-treated wood? Do I need to worry about toxins? I guess that's a bad idea - the soil will be in contact with the wood, albeit through landscaping fabric, but still, the toxins will leach into the bedding material. That means pine or cedar lumber. And only cedar if I use fence boards.

I like the idea of that mobile seat, but I'm not sure my wife will give up the extra space for it to fit in the aisles if I tell her she'll need to consider one.

I hadn't thought about an active watering schedule. That would greatly enhance veggie growing.
I had a soaker system on a timer at my old house, but that won't work with raised beds. I'll have to think of something else. Gravity-fed would be quite awkward. I'd need a 50 gallon drum up on a table and hoses everywhere.
 
The new stuff is a lot safer but untreated hemlock or cedar is better. The "secret" to slow rotting is to keep moisture moving away from the wood. Membranes, gravel and clean fine soil all tend to wick rotting moisture away from the wood. It won't stop the rot but it will delay it and increase the stability of the structure.

A cooking and planting deck foundation. Using direct ground contact quality PT lumber because all plants will be in pots.
https://www.capitolcitylumber.com/all-treated-lumber-is-ground-contact/
Ground Contact Lumber
Ground-contact lumber is pressure treated with chemicals to withstand the effects of being close to the ground, in contact with the ground, or exposed to continuous moisture.

Ground contact lumber is made for outdoor projects where the wood is exposed to all types of weather or has a high potential for decay. This includes salt water exposure.

Above Ground Lumber
Above-ground-contact lumber is treated to withstand rot and decay even when it physically touches the ground, water, or leaves. Any above-ground lumber is treated to a lower standard of resistance.

It’s often been talked about using “Above Ground Treated” lumber or lumber that is 18” above ground level and will not be exposed to an area that will stay moist due to the treatment being lighter on this wood.
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The drying zone under those surface wood planks. Helps to stop warping and rot.

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Time to re-stain the surface wood.
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Last year's crop.
 
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DaveC426913 said:
How do I build the frames without rotting the lumber in contact with the ground?
BitD in Northern California we used untreated redwood planks, ubiquitous and inexpensive at that time, placed in trenches in the soil and also to pin down fabric and contain mulch. Redwood lasts for years, longer than red cedar planks IME, though cedar makes superior mulch.

Mother developed an effective strategy against pests particularly snails and slugs. Plant a border of various marigolds and related daisy flowers that look nice while inhibiting certain pests. AFAIK bees are not harmed.
 
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  • #10
Klystron said:
Mother developed an effective strategy against pests particularly snails and slugs. Plant a border of various marigolds and related daisy flowers that look nice while inhibiting certain pests. AFAIK bees are not harmed.

We used a exterminator in our fish facility where we didn't want toxic chemicals that might hurt the fish or other animals in the biology building. This exterminator had a big emphasis on using plant extracts to repel certain pests. We had lots of roaches and silverfish living off of spilled fish food (very nutritious).
 
  • #11
DaveC426913 said:
And I guess what I line them with is landscaping fabric?
As far as I'm concerned agricultural (PE) foil is preferred for the sides. Something UV resistant and waterproof.
Unless you are worried about moles and other critters, nothing is required on the bottom. And that'll take care of the drainage too.

DaveC426913 said:
Is it OK to build them out of pressure-treated wood? Do I need to worry about toxins?
That's why the PE-foil. Unless you can do it really cheap and replace it every two years or so (why every DIY woodwork burns down to the free wood pallets at some point?), some kind of treatment will be needed, and yes, the usual treatments are usually considered toxic.
Some people recommend linseed-oil as treatment. I found it inadequate for wood in contact with soil.

DaveC426913 said:
I like the idea of that mobile seat
Well, if you chose the height right and put more than one of those raised beds in a row, then you can use one of them as a seat while tending to the other one.
 
  • #12
Rive said:
...


Well, if you chose the height right and put more than one of those raised beds in a row, then you can use one of them as a seat while tending to the other one.
The seat I have has a long worm screw for seat height adjustment.
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I have the 300lb+ Heavy duty version.
 
  • #13
nsaspook said:
I have the 300lb+ Heavy duty version.
If I got this for my wife, my body would never be found.
 
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  • #14
DaveC426913 said:
If I got this for my wife, my body would never be found.
Make it, her idea. :wink:

I also have the work shop rolling chair.
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Bad knees are not going to stop me from working at home in retirement.
 
  • #15
nsaspook said:
Make it, her idea. :wink:

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Yeah. Unlikely that's going to happen, either way.
 
  • #16
At the park today they were setting up some vegetable planters.

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PT supports for what looks like a cedar or hemlock soil box.
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Adjustment to see under a little better.
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  • #17
Prototype done.
Dimensions: 49" x 23" x 25.5" *
* specific dimensions were set by the width of the fence boards: 9x4
Cost: ~$100 in lumber
Labour: ~4h
Open bottom, spikes in four corners (not necessary, it's going to weigh a ton)
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I have yet to line it with landscaping fabric before I secure the top rails. I was going to run landscaping fabric right around whole inside including the bottom, but I think the sagging of the dirt will drag it down and pull it off the inner walls, so maybe I won't line the bottom.

It has no bottom so I'm a little concerned that a ton of dirt will start leaking out from under the bottom. I will pound it in with the sledge, but I stil think it will leak.
 
  • #18
The project scope is creeping.

I'm going to level the area (about 15'x15') with gravel or stones. I'll hold the gravel/stones into a big square with railway ties spiked into the ground.

The last tme I tried to make a walk area with stones around my aboveground pool, they all got stomped into the mud and it made a mess. So I'm a little trepidatious about that.


And then I've got to figure out a watering system. I'm not sure soaker hoses will work in raised beds unless the entire watering system is at the same height. Soaker hoses don't do well with changes in height.
 
  • #19
OK. I have no idea how to prep the ground.

This is my guess.

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Garden Plot:
  • The area has had landscaping fabric laid down to kill what's been growing there to-date. I'll leave it in place.
  • I'll throw a few inches of pea gravel down, over a layer of sand to stabilize it.
  • The whole area - about 15'x15' - is surrounded by edging (prolly ersatz railway ties) to keep the gravel in.
Planters:
  • The planters sit on the pea gravel.
  • The (open) bottom of the planters will be covered in fine 1/2" mesh to prevent critters burrowing up into the planters.
  • The inside walls of the planters are lined with waterproof liner, so water isn't lost through the wood planter walls.
  • The bottom 6" of the planters will be filled with rubble / clean fill. (We only need 18" of soil for gardening, but we want the planters to come up to 24".)
  • On top of the fill, a layer of landscaping fabric, to prevent good soil from getting lost in the rubble/fill below.

Again, this is a guess. Is this over-engineered? Anything I don't need?

The only thing I want to avoid is having to do any digging/leveling of the area as part of the prep. I just hate digging out a giant area (225sq ft.).
 
  • #21
Tom.G said:
A step up from waterproof liners, which can get damaged over the years, would be pressure-treated wood to resist decay when used outdoors.
The whole thing is made out of PT wood.

The liner is to stop precious moisture from leaking out.
 
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  • #22
DaveC426913 said:
Is this over-engineered?
Honestly, I think it is. But it'll work just fine.

Depending on the length of the box and the height of soil inside you may need to tie the opposing sides together somehow.
 
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  • #23
Rive said:
Honestly, I think it is. But it'll work just fine.
What would you eliminate?

I've already discovered there's a 6" grade from one corner to the other. Now I'm going to have to dig grooves for edging to level the whole thing.

Rive said:
Depending on the length of the box and the height of soil inside you may need to tie the opposing sides together somehow.
I've seen these centre braces on larger boxes.

Mine are only four feet. Soil is 18" (more like 14") on top of 6" rubble.
And they're made of 2x4.
I think it'll be all right.
 
  • #24
Raised beds cost too much money. Lumber, screws, nails, potting soil, will cost very near $100 per bed. Potting soil is not real soil it is composed plants and has almost no food value of live plants. If your yard is rock you may have no other choice but to have beds. The taller beds are the dryer the soil is. Plants do not like uneven soil moisture. You need drip line irrigation or manually water plants every 2 hours all day depending how hot and dry your geographical location is. I took, biology, horticulture, physics, electronic, FFA, chemistry, engineering, and more it college, that was educational but it did not prepare me for growing a home garden. Your beds will work fine made with 5/4" PT lumber setting on your yard. If you don't like bending over put 3 ft tall legs on the beds. Beds need to be hand weeded. Tomatoes grow best on 6 ft tall stakes. 10 bird houses are very helpful to kept bugs gone. Learn about fertilizer, NPK. N is nitrogen, P is phosphors, K is potassium. N is very quick to be gone in soil in 3 months if your weather is 100°f. P will build up and become toxic to plants if your not careful. K builds up in the soil also. Lots of rain washes high P away to a safe level in about 5 years. Rain washes away K in about 10 yrs. Certain plants need calcium to prevent BER= Blossom End Rot in, tomatoes, peppers, squash, melons, cucumbers, peppers. Corn only needs nitrogen and does not pollenate well with less that 300 plants. Farm supply sells fertilizer in 50 lb. bags $20 each. So called organic plant food in small 5 lb. bags is $20 each. Get a soil test every year and learn how to read and understand a soil test many of the place that do soil test has no clue what the numbers mean. Learn the correct date to plant each plant. Most vegetables need to be planted after your last frost, beans & corn soil temperature needs to be warmer than 65°f. Plant potatoes & onions 6 weeks before last frost. I tried beds once, waste of my time and money and too much work. I do low maintenance garden I seldom do 15 minutes work per week in my 30ft x 60ft garden. About 1st week of June I will have 600 lbs. of potatoes to dig up. Tomatoes will be ready to pick about 1st week of July to Nov. 350 onions & 100 garlic will be ready to harvest about June 20. 5 kinds of peppers should be ready to pick July 10 to Nov. 450 ears of corn harvest about Aug 1st. 4 kinds of melons harvest from July to Nov. Beans July 15 to Sept.

Garden3.JPG
 
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  • #25
gary350 said:
Raised beds cost too much money.
Thanks, but surely cost-benefit ratio is my decision. For me, it is a fixed parameter; a given.

The reason it's a given is because of mobility and accessibility of the gardener, which (unless you know something I don't) is only going to get worse, not better.

How much of the rest of your post is still germane, based on the firmness of the 'raised bed' requirement?
 
  • #26
DaveC426913 said:
What would you eliminate?
Nothing. It's about personal preferences/experience, and the fact that here the most common solution is simply to throw some used, cheap paller risers directly to the ground (with a PE-foil inside) should not limit your design.
 
  • #27
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  • #28
12x12 Bed finally laid. One planter in-place.

That's $450 for 3 yards of stone. (OK, it's $200 in stone plus about a 100% markup for delivering it in cubic yard bags, rather than dumping it all over my driveway.)

First planter (4'x2'x2') cost about $110, each subsequent is getting much cheaper and faster.

Each planter will require about 12ft3 of fill - 1/3 rubble in bottom and 2/3 soil on top.

20250527_142036.webp

So,
Bed: wood+gravel=$500.
Planters: 7x$100=$700.
Soil: 2yds=2x$180=$350.
Total: $1550.

How long do you think it will take my wife to produce $1550 in vegetables to make this a profitable initiative? o0)
 
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  • #29
DaveC426913 said:
12x12 Bed finally laid. One planter in-place.

That's $450 for 3 yards of stone. (OK, it's $200 in stone plus about a 100% markup for delivering it in cubic yard bags, rather than dumping it all over my driveway.)

First planter (4'x2'x2') cost about $110, each subsequent is getting much cheaper and faster.

Each planter will require about 12ft3 of fill - 1/3 rubble in bottom and 2/3 soil on top.

View attachment 361491
So,
Bed: wood+gravel=$500.
Planters: 7x$100=$700.
Soil: 2yds=2x$180=$350.
Total: $1550.

How long do you think it will take my wife to produce $1550 in vegetables to make this a profitable initiative? o0)
Why would anyone want to loose money on purpose? Fun hobbies loose lots of money on purpose. I spent about a $1000. on model airplanes to have FUN. I spent $1000. on long range target shooting it took a year to learn how to shoot 100 aluminum soft drink cans 1/4 mile away and never miss. I wasted money when I first started gardening, after I learned the correct way to garden it saves us about $4000. on food every year. If your having FUN don't worry about the $$$$$.
 
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  • #30
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  • #31
305 lbs. of new Kennebec white potatoes from a 90 ft row of seed potatoes.

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  • #32
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Out of control. :biggrin:
 
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