I’m renting an older house that has a rather large yard. The strip of yard alongside the front door slopes towards the house, so that every time it rains, there is an ankle-deep pool leading up to our only entrance. Fortunately, the house itself sit up off the ground about a foot an a half, and it’s not my sinking foundation.
So I had the idea of putting a raised garden bed on this part of the yard, sloping it in the opposite direction as the lay of the land to make it level across the top maybe.
Would this be effective at catching the rain to prevent lake formation next winter? Or would the water just seep out around the timber? What if I bury the retaining timber a couple of inches? The soil around here is almost entirely clay and gravel.
Is there anything more complex to making a raised garden bed than getting some pressure treated 2"x12"s, nailing them into a box, and filling up the inside with peat?
Any one got eatable plant recommendations for someone in the central valley of California with no green thumb?
There is a sprinkler on that corner, which I could put a taller sprinkler head on so it spritzes above the level of the garden bed.
But I’m not convinced raised beds will solve your drainage problem, unless you excavate and replace with a sand modified soil.The site probably needs swales or other re-direction of water.
Consensus pretty much says don’t use pressure treated wood around edibles,though much like raw milk,some people aren’t convinced there is proven harm.
Raised beds are raised to stop compaction, improve drainage of the bed, and allow the soil to heat up a bit before the surrounding area. You need to slope your lawn to drain away from the house.
Hi Pullet, I don’t understand the lay of the land as you descibed it, so I can’t comment on the effectiveness of the raised bed for drainage control.
Making a raised bed can be as simple as heaping up dirt, or as complicated as building raised boxes on legs (usually used for older folk with less mobility). I’d highly reccomend Mel Bartholemew’s (sp?) Square foot Gardening. http://www.squarefootgardening.com/
I would not used pressure treated wood if growing veggies, as they can leach arsenic (older pressure treated) or who knows what else (Newer “safe” style pressure treated).
Peat holds lots of moisture, but it’s low in nutrients. See Mel’s website for his soil mix.
This is not a big deal, IMHO. You can just tack plastic sheeting to the interior of the box to keep any seepage from the wood away from the rest of the soil.
Sure, this may be fine, but do you know what, if anything, leaches out of the plastic? I don’t, and untreated wood lasts for several years. IMHO, better safe than sorry.
Your question, as you’ve gathered, is a bit complicated – and hard to answer without a better sense of what the problem is that you’re trying to solve. Any chance you could link to a couple of pix?
I don’t have time to give a long response right now – but will suggest that what you’re actually asking about is terracing, not raised beds – try googling that and see what you come up with.
Raised beds tend to be fairly well drained because the soil you fill them with won’t be as packed as the natural soil.
A raised bed might be nice, but I don’t think it’s a very good solution to a drainage problem - you’d be far better off digging a ditch and installing a gravel soakaway or tile drain or something like that (still do the raised bed, if that’s what you want).
Good points. I’ll add that I’m in California, so whatever watering the soil gets only happens because I’m irrigating. Which means that there’s little seepage in any case, because wet soil isn’t in contact with the wooden box. Pullet’s weather sounds quite a bit wetter than what I experience, so different concerns may apply.
OTOH, I do use sandwich bags and such without fear, so I don’t think plastic sheeting is particularly sinister.
Plastic sheeting in a garden bed will last only a couple of years before it comes apart. You can use landscape blocks for a border. Composite deck boards are usually 6 inches wide, and you can double for 12. They don’t leach anything. Still, if you don’t make a way for the water to escape, you’ll still have the problem.
The old style PT lumber was pulled from the market over four years ago - this stuff was called “CCA” and it had arsenic.
Now, the stuff you can buy is either “CA” (copper azole) or “ACQ” (ammonium copper quat) - no arsenic in either formula, although some quick poking around makes it sound like the EPA had approved CCA lumber for building gardens - apparently the arsenic doesn’t migrate from the wood and into the soil.
Redwood or cypress would be good choices - either will probably last 10-15 years without needing any special treatment or care. Of course, there’s a downside - it’s expensive! Just a week ago, eight-foot 2x4 redwood was selling for $16 a stick, so I quickly revised my plans to use the PT lumber for $9 a stick. (I was building a platform base for a garden shed.)
Depending on how big a raised bed you want, you could compromise on the construction and mix the woods. I’m looking at building something that’s going to be not so much a raised bed as a three foot high retaining wall, and I’ll probably use redwood for the bed walls and PT 4x4s for the structural posts that will be sunk into the ground on the outside of the wall.
One thing you don’t want to use is old railroad ties, telephone poles or anything that’s been treated with creosote. The EPA has listed it as a probable carcinogen. It’s also icky stuff - it’ll stain your hands and clothing, and it stinks in hot weather.
My front yard is sloped down towards my neighbors garage and all my water would drain there, despite all my aerating efforts. So the neighbors garage part looked all lush and green and my yard looked like something the devil trod upon.
So I dug out the slope into a simple rain garden so there was no more run off and it does very well for both flowers and vegetables, (cukes, zucchini and jalapenos). I am putting another one in this spring, but I haven’t decided yet whether to plant cosmos or turnips.
I’ve made a two-layer raised bed garden in my yard. The overall shape of the bottom section was L-shaped and then I added a second layer of smaller boxes on top. I love it love it love it. Weeding is easier. Watering is easier. I combine annual and perineal flowers and vegetables so the garden looks nice all season long. I started my raised bed gardening with Mel Bartholomew’s book (linked above) and found it very, very helpful.
The main thing here is: as a horticulturist, I answer this question again and again and again— even if you do raised beds, unless you have optimal loamy soil— till the area underneath the beds. Break the soil up, at least a little bit, especially if it is a new house, where the topsoil has usually been scraped away.
By breaking up the hardpan underneath, and layering in topsoil and compost (full of all the necessary microbes for healthy soil), you are allowing the plant roots and amendments to work the soil at a deeper level.
Plastic sheeting just creates a barrier to deeper plant roots, so you’ll have to water more, so, not the best choice. I am a big fan of till well once, to break up the soil, then work on that top layer: 6" good compost to start, then mulch every year, add a bit of compost as made, mulch again. Even with crappy soil, this gives you great soil in 3-5 years.
Think of compost like all the probiotics you see advertised now, for our human guts. There are good ones, which keep out the bad ones. Compost has all the good stuff, and helps plants fend off diseases, like yogurt does for our innards. Peat, by itself, doesn’t help with that. .
I could go on here, but, will just let it go to your specific questions, and, glad to answer.
Since my main goal is drainage, maybe I’ll just try the rain garden idea. If I understand it right, that would require planting right along my patio, at the nadir of the slop, right? Would that encourage the patio concrete to sink? Having all that water drain there?
Will try to post pics ASAP. That part of the yard was originally a gravel driveway. The gravel has now sunk into the clay, and the grass and weed grow wild over the top.
Should I try simple aeration first? The whole yard could probably use it. I don’t think anyone has done anything aside from mow the grass in decades.
Pictures would really help here, Pullet, also, evaluate the sunlight situation so that you can put the appropriate plants to thrive there. Forgive me if I’m not so wordy here, I’ve been answering plant questions all day long; it’s my job, which I love, but about talked out today.
