Garden depth?

[Cpl. Klinger]

Last spring, we put in a small backyard garden. We built it out of 2x4s, but only the 4 inches deep. It did sort of ok, but our crop was rather lackluster. I've thought that maybe we need to make the garden deeper in order to have a better soil base. The general soil base of our addition is pretty rocky and sandy, though the farmers field at the noth end does well with corn/beans. What would be a good depth to build the garden out to in order to better the yield? I'm probably going to combine this build with building a hide spot for a rain barrel as well (keep it out of the HOA's prying eyes). I'm thinking maybe a foot of soil depth, on top of a few inches of rock base?

 

[88GT]

Are you building a raised garden surface on top of existing substrate?

IMO....No need for the rock base, especially if your underlying substrate is already rocky and sandy. Ameliorate the soil you do add with peat or some other substrate than enhances drainage. Rocky substrates are never beneficial and can be harmful, particularly to root crops. I've always read that a minimum depth of 8-12" was necessary for the best results. I have raised beds built from 2x12s. 8 of the 12 are built on an old raised flower bed area that was mulched with small rocks. I have bountiful harvests.

One more thing I just thought of...is your gardening plot one large plot or several raised areas within a defined border?

 

[Cpl. Klinger]

Right now it's one large plot with a divider in the middle, about 3' deep by 20' wide. That's where we were trying crops like peas, green beans and the like. The only thing that has even done well is the kohlrabis both years. What I'd like to do is shorten it about 3 feet for a rain barrel setup, then make it about 12" tall the whole length. I do want to make sure that drainage is well taken care of, because this setup is right up against the back of the house. We're on a slab, so no worries about leaking into a crawl or basement, but I know I don't want a lot of water dwelling around the house.

 

[88GT]

Right now it's one large plot with a divider in the middle, about 3' deep by 20' wide. That's where we were trying crops like peas, green beans and the like. The only thing that has even done well is the kohlrabis both years. What I'd like to do is shorten it about 3 feet for a rain barrel setup, then make it about 12" tall the whole length. I do want to make sure that drainage is well taken care of, because this setup is right up against the back of the house. We're on a slab, so no worries about leaking into a crawl or basement, but I know I don't want a lot of water dwelling around the house.

You're actually dealing with two drainage issues. The first is the actual permeation of water through the soil depth in the garden area. That you easily control with the proper mix of substrates. The other one, which is what you mentioned above is determined by the topography of the ground. As long as there is adequate slope now, you shouldn't have any real issues with water around the foundation. What collects in the garden will eventually make it to the base topography you have now and will simply flow off with the rest of water that didn't collect in the garden.

 

[Cpl. Klinger]

There is a pretty decent slope away from the house, so now that I think of it that shouldn't be too much of an issue. Especially if I divert a lot of the water into a rain barrel that previously would have been hitting the ground. Sounds like I have a project for the spring now...

 

[cosermann]

Soil is a good place to start, but there are LOTS of reasons your crop may not have done well.

What were you trying to grow?
How much light does the plot receive?
What are your watering practices?
Did you do a soil test?
Did you use fertilizer?
Where you bothered by pests?
Etc.

 

[ocsdor]

Since we are on the subject of soil, one thing I recommend doing now is gathering up as many leaves as possible (even from neighbors), and put them in the garden, mulch, and till them into the soil.

Your low yields of peas and beans could be from lack of sunlight and/or planting at the wrong time of year.

 

[Cameramonkey]

Since we are on the subject of soil, one thing I recommend doing now is gathering up as many leaves as possible (even from neighbors), and put them in the garden, mulch, and till them into the soil.

Your low yields of peas and beans could be from lack of sunlight and/or planting at the wrong time of year.

THIS! Until this year I didnt truly appreciate how sensitive some crops are.

Growing up, grandma always planted peas, lettuce and green onions the weekend after st patty's day. This past year I decided to try onions on top of the other two I have done since I bought the house.

I misplaced the onion seed packet during the regular planting time. about the time I decided to try a second planting of lettuce in June after I cleared some crops that failed I also found the onions so I planted those as well. The lettuce was miserable and didnt get past 1", and the onions didnt even germinate.

Fast forward to the fall. Several weeks ago I was moving around the tomato vines and other scrub I had pulled and set on top of the garden to dry so I could burn/compost it. As I was moving it I noticed something deep green. It was one of the onions. It finally got cool enough again for one of them to germinate and it was actually about a week short of being ready to harvest (had I not disturbed it).

Never underestimate when they say to plant your stuff.

Also, in this area, root veggies can be VERY hard to grow. The PH of my soil makes radishes "hotter than blue blazes" as grandma would say, and the density is hell on anything deeper than 3" like turnips and beets. Carrots are a joke in my garden.

 

[Cameramonkey]

Hoping to double the size of our garden next year, and convert it to a raised bed as well.

 

[Cpl. Klinger]

Since we are on the subject of soil, one thing I recommend doing now is gathering up as many leaves as possible (even from neighbors), and put them in the garden, mulch, and till them into the soil.

Your low yields of peas and beans could be from lack of sunlight and/or planting at the wrong time of year.

The sunlight definitely could be an issue, since this is on the backside of the house facing due west. And it might change again this year due to a new house being built right behind us. I don't realyy want to try and move this, since where it's planted is an effort to keep it out of view. May have to reevaluate things in the spring after some research over the winter.

 

[Zoub]

though the farmers field at the noth end does well with corn/beans.

That tells you everything you need to know. You are in a development. Unlike your land, his still has the topsoil, yours was removed.

Not only do you want to amend the soil but aerate and loosen deep enough so that roots will have an easier time growing in the soil and a better growing environment when they get there. When you loosen the soil dig the depth at least 1.5 to 2 times the length of your shovel blade. Dig out the first layer, then dig the next layer in the hole or trench until it is good and loose, amend it, mix it, then mix in the first layer of soil you removed and mix that, amend it as well. You will end up with a base of 18" to 24" of good soil. Then if you ever build raised beds on top of that, even more. Good soil, aeration and drainage.

It would not hurt to get a soil test done this winter so you know your PH. We are dropping one off with our local greenhouse this week because we have a new garden we are working with.

In your location, assuming the bed may be along a fence, look into using the Florida weave technique to grow certain plants taller and make use of your vertical space. If this fails, our house in Indy is for sale and there are multiple raised beds inside the fenced in backyard, some set up for the weave technique and plenty of sun. Yes, this is what you should do.

 

[Cpl. Klinger]

That tells you everything you need to know. You are in a development. Unlike your land, his still has the topsoil, yours was removed.

Not only do you want to amend the soil but aerate and loosen deep enough so that roots will have an easier time growing in the soil and a better growing environment when they get there. When you loosen the soil dig the depth at least 1.5 to 2 times the length of your shovel blade. Dig out the first layer, then dig the next layer in the hole or trench until it is good and loose, amend it, mix it, then mix in the first layer of soil you removed and mix that, amend it as well. You will end up with a base of 18" to 24" of good soil. Then if you ever build raised beds on top of that, even more. Good soil, aeration and drainage.

The ground we're on now, once you get down past a few inches turns into very thick clay. Would I bea able to get by with using a tiller to turn the soil over and then mix in top soil, building up the base as I go? I still plan on ripping out the 2x4's this spring and upgrade to 2x12's to raise the depth of the soil.

It would not hurt to get a soil test done this winter so you know your PH. We are dropping one off with our local greenhouse this week because we have a new garden we are working with.

That sounds like a plan. I'll be looking into this soon.

 

[88GT]

The ground we're on now, once you get down past a few inches turns into very thick clay. Would I bea able to get by with using a tiller to turn the soil over and then mix in top soil, building up the base as I go? I still plan on ripping out the 2x4's this spring and upgrade to 2x12's to raise the depth of the soil.

If you are going to upgrade to 2x12s, then you don't need to worry about the soil below. My beds are 2x12 plank-sided and I have done nothing to the ground below them. If all 12" of your bed will be above the current soil level, it will be a waste of time and money, IMO.

I don't recommend tillers in garden use unless you're starting the garden for the very first time and breaking up raw ground. There's a phenomenon called tiller pan which creates a specialized cased of subsoil compaction with repeated used of the tiller. If you're not familiar with hardpan, it's a physical barrier of soil which significantly slows the movement of all things through that layer, including water and beneficial worms. There is no point in tilling the ground if you will be building it up to fill the 2x12s. It wouldn't hurt, I suppose, but it's not necessary.

As you will probably have to buy dirt to fill the beds, use that opportunity to create the perfect soil. To be honest, it's not hard. I mix in some peat and composted manure every year in the spring. There are things you can add in fall to help too, but since I have found that I have to add in a few bags of dirt every year anyway, I just use spring as my amelioration time period. Then I fertilizer with a small amount of fertilizer during planting and once during the season if things are looking like they need some TLC.

You can buy home soil test kits, but I am not sure that they are really all that necessary at this stage. In my 4 years of gardening now, I have never felt the need to have the soil tested because of poor production from the plants. Note: this is only applicable if you add top soil and amendments to the beds to build it up. If you are relying on the existing ground soil for the garden, then there might be some benefit to knowing what's in there.

Finally, I recommend The Vegetable Gardener's Bible by Edward C. Smith. Quite frankly, it might be the only vegetable gardening book a man would need. It has been my go-to resource every year. Simple and easy-to-understand, it provides all the information you need for successful gardening, without overloading too much on the minutiae of the science. It covers everything from planning and prepping to sowing to cultivating to pests to harvesting and storing.

 

[dirtfarmerz]

Not trying to hurt your feelings, but there are thousands of people that grow stuff in pots just fine. Some vegetables are grown in water. It's what you feed the plants. The farmers doing the row crop stuff have dead dirt. Not very much grows in their fields between harvesting. Healthy fields will grow grass and clover, but the farm fields we see are barren until something is planted. You can see 2 foot tall yellow corn in the corners and edges where they don't spray fertilizer and 1 foot away you'll see tall, green corn where they sprayed. It's just chemical fertilizers.

Don't use chemical fertilizers. Don't waste your money on soil testing. The big farmers have to do that because their soil is so depleted that they have to find out what it will take to grow their crops. Find some compost; even better if there's chicken and cow manure in there. The link has some of the best organic fertilizer you can get. Growing stuff sucks the life out of the ground, you have to put something back into it.

AGGRAND

 

[cosermann]

Interesting "advice" in this thread.

My folks were raised on farms, and I've gardened all my life; with and without soil (hydroponics).

Plants need light, water, and nutrients.

And yes, you may NEED a soil test, if for nothing more than to determine the pH of your soil. If it's really out of whack, you're plants won't be able to make efficient use of the nutrients that are there. They'll be able to assimilate the nutrients in your soil much better once the pH is adjusted whether you supply those nutrients organically or inorganically. If you don't test, you don't know. Once you know, you can fix it or cross that variable off the list and look elsewhere.

With dirt farming/gardening, your soil can give you issues if it has poor structure, poor drainage, and/or non-uniform texture.

However, with the exception of some root crops (carrots, potatoes, etc.), most of the annuals folks tend to grow in their gardens are fairly shallow-rooted. Peas, greenbeans, and kohlrabis certainly don't need 12". So, you really do not need a 12" raised bed unless you're trying to solve another problem, like drainage, or want to grow something with deeper roots. And, FWIW, my potatoes do just fine in southern Indiana clay with a 5" raised bed on top of it.

So, do you have adequate light (how many hours of direct sunlight per day)? - a location issue, sometimes not easily fixed unless you're willing to chop down trees, etc.

Are you providing adequate moisture? - this gets at your watering practices. Too much moisture is as bad as too little. You can kill with kindness or neglect.

What is your soil structure/pH/current macronutrient content?