I have zero topsoil!!! what do I do?

meemzyinphillyJanuary 20, 2014

I live in Philadelphia, which as some of you may know I'd filled with vacant lots (about 40,000 of them). I have plans to turn one of them into a kitchen garden. It's about 1200 sq feet The location is perfect, its only a two blocks from my house, and it's gated.

However, it has no topsoil.

This particular lot was cleaned up about 15 years ago. It was planted with decorative perennials only to be forgotten and weeded over. When I checked it out initially I saw spots of deep humus rich black soil. When I checked again this afternoon to do a simple mason jar soil sample, I found to my surprise the the good stuff was just 3 or 4 inches deep.
Under the compost was black plastic and under that, fill dirt.

So now I'm trying to figure out what to do that won't make this project too costly. I can maybe afford to buy 4 cubic yard of unscreened leaf compost or split it in some ratio with composted manure.

Should just cover the whole thing and make it a giant "raised bed"?

Could I mix in the stuff that already there with the fill dirt to make an artificial topsoil?

I really don't want to make individual raised beds since they are pretty expensive.

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1200 sq ft is a nice size. I do prefer beds because no one walks on them.

If you want to do it nicely and cheaply, you will have to have a little patience. Wood chips are free and they will give you good soil, but it will take time. In the first year, you will fill the beds with chips and plant large plants through the chips (tomatoes or squash seedlings, etc.). You will have to fertilize chemically, specially with nitrogen (it is worth buying a 50lb bag of urea at an ag supplies store). You can also plant large seeded plants, such as garlic, potato and beans.

In the second year and beyond there ought to be enough humus that the garden only needs nitrogen. In each bed, you should put over one foot of wood chips to get that first inch of top soil everywhere. In later years, if you can bring leaves and kitchen scraps, earthworms will keep on working your soil.

My current garden has beds made of cinder blocks, but in my first garden I used recycled aluminum window shutters and shower doors, held in place by stakes made of recycled plumbing. If you are patient enough, you will find a tree company that will dump a 30 cubic yards load of chips in the garden.

    Bookmark   January 20, 2014 at 9:49PM
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mad_gallica(zone 5 - eastern New York)

Buying leaf compost. That is definitely a new one.

Start calling around. A lot of municipalities do their own leaf composting, and offer it free to their residents. Sometimes residents means you have to show some proof. Other times it means you live close enough to get there with a car and a shovel. Sometimes they just want somebody to take it away. Anybody who is doing leaf collection has a pile somewhere. All you have to do is find it.

So long as the fill dirt is 'clean fill' - no trash, glass, or things like that, it can be improved with organic matter. Depending on what the added soil is made of, it is possible that simply mixing the two will do what you want.

    Bookmark   January 20, 2014 at 10:54PM
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If possible remove that plastic. It does nothing good and can inhibit the drainage you need. Then concentrate on making the rest of what you have into good , healthy soil.

"Topsoil" is the top 4 to 6 inches of soil, That usually contains about 5 percent (I like 6 to 8) percent organic matter, that leaf mold.

    Bookmark   January 21, 2014 at 7:41AM
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wayne_5 zone 6a Central Indiana

I'm assuming that that black plastic is weed block. I tend to favor removal of it to help build a deeper base.

    Bookmark   January 21, 2014 at 11:07AM
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I too would remove the plastic. Start in a small area the first year and work your way around at a reasonable pace.

Tilling compost into the soil beneath is good. It's not exactly artificial topsoil, it's actually the way nature does it, adding decomposing organic matter to the soil. It's just artificially sped up. :-]

You might consider testing the soil for lead though, since inner city lots often have high lead levels. It's fairly inexpensive to have done.

    Bookmark   January 21, 2014 at 11:47AM
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First of all, that you for your responses.

The city does have leaf compost, but you only get 30 gallons a week if you're a resident. Otherwise you have to pay by the ton. Since I don't have a truck I would have to get it delivered so I figured I would go with a landscaping company that delivers. I'm starting a worm bin so hopefully I will never need to buy compost again!

I was also worried about lead contamination, but the soil is a replacement, and the houses in the vicinity are red brick and haven't been painted at all. I'm pretty sure the site was tested for lead in 2001 because it was part of the city's mural art program. Kids usually paint the murals and they have to ensure safety. I am still planning on taking samples to the "soil kitchen" where it can be tested for heavy metals free of charge.

It's pretty clear that I should rip up the plastic.
I'm pretty sure that the black upper soil is a mixture of leaf compost, decomposed wood chips, decomposed weeds, and remnants of the what they planted originally.

My plan would be to rip up the plastic, till the soil mixture and subsoil in about 8in to a foot and then put the new compost on top. I could also add some composted manure in there too.

    Bookmark   January 21, 2014 at 12:25PM
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My plan would be to rip up the plastic, till the soil mixture and subsoil in about 8in to a foot and then put the new compost on top. I could also add some composted manure in there too.

You don't need to till - just get that plastic out of there and the roots and worms will do it for you.

Focus on a small enough area that you can do it thoroughly. It's better to do a small section well than skimpily adding compost to the whole 1200 feet.

1 - Rake back the top layer and remove plastic from one area of suitable veggie bed size - maybe 5x20.

2 - Replace the top layer in that area and plant vigorous and reliable species.

3 - Do another section, leaving the paths between them, but instead of planting, every week get your 30 gallons of compost and spread it thickly over part of the new bed ... after the bit is covered, plant something.

Over the course of the season you should be able to improve the growing beds considerably without spending a lot of money on improvements.

    Bookmark   January 21, 2014 at 9:00PM
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I believe lazygardes' plan is a good one. A single 40' row done right is more productive than 6 improperly prepared rows. Not to mention far less labor. If fertilizer is to be applied,I would broadcast it before removing plastic so it will be mixed while moving soil. Once plastic is gone you might consider building 4' wide beds by moving good soil from a 3' path to the bed,leaving the 3' path bare to fill dirt. As lazyg mentioned,grab and use your allotment of compost every week for the beds. Any excess compost plus leaves,grass clippings,shreaded paper,kitchen scraps and other material can be put on paths to walk on and/or tilled in to build soil for next year. You need to start composting material on site for use as it matures. Hopfully water is available.

    Bookmark   January 22, 2014 at 12:50AM
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I was going to have the compost delivered since I don't drive. I have to buy a minimum of 3yds. The compost is only $26 a yard plus a $65 delivery fee. It comes out to be only $30 more than buying from the city and its delivered right to the lot. I figured that way I could use the free allotments for manure and mulch.

Labor is the one factor I'm not short on. My best friend and boyfriend are both contract workers who will be on a long vacation for most of March and they love doing stuff like that. I know I can't get it done in a weekend. But in a week I think the three of us could tackle it. I planned on 8, 5'x10' beds and 8, 3'x3' mounds for melons and other cucubits. So only about 500' sq.I thought

So do you guys think I shouldn't till? I should've taken pictures and now the city is covered in snow.

Water is a big concern. It does average about an inch a week but I'm also having rain barrels installed. The city does it for free and it includes the rain barrel. I'm also getting a worm bin started for extra compost and worm tea.

    Bookmark   January 23, 2014 at 1:51AM
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prairiemoon2 z6 MA

There's an article on GW about the Interbay Mulch system that some people are trying now, that according to reports and testing done, produces a lot of very biologically active humus in a short period of time. Just do a search on GW for Interbay Mulch.

    Bookmark   February 1, 2014 at 7:19AM
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wayne_5 zone 6a Central Indiana

"So do you guys think I shouldn't till? "

For myself I prefer at least an original till or stirring to incorporate organic matter deeper into the soil structure.

    Bookmark   February 1, 2014 at 10:20AM
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3-4 inches of "good stuff" isn't bad at all as a top profile. A lot of people are barely working with 1-2" in disturbed soils.

Improve aeration/infiltration and/or provide an environment for microbes/worms to do their thing below that...along with what the roots of what you plant will do in mixing it deeper...and you should be good to go in short order with some top applying or light tilling of composted organic matter.

I, too, prefer an initial tilling of organic matter into a new soil bed. It's a lot easier to go no-till after an initial conditioning. It rarely leads to disadvantages of tilling such as hardpans or "burning" of organic matter that may occur when you do it every season.

This post was edited by nc-crn on Sat, Feb 1, 14 at 11:15

    Bookmark   February 1, 2014 at 11:12AM
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prairiemoon2 z6 MA

I think you can do it either way, you can use methods that are more 'permaculture' and do sheet composting, lasagna composting or Interbay mulching which piles up 6-18" of organic matter on the surface of the soil. Any of these methods will transform your soil to healthy workable soil. This can be a no dig method. Many many books on the subject, starting with Ruth Stout and no digging, and many versions of that since then. There are people who believe you are better off not disturbing the structure of the soil by 'turning it over'. And if it's true, that 2/3 of the microorganisms in your soil are on the surface or very close to it, it's easy to see how 'turning' it over is a disadvantage, when you are trying to get those same microorganisms to work on your organic matter.

I agree with nc-crn, that to open the soil to air will speed things along, and you could still sheet compost on the surface after you dig. Personally, I would want to double dig by hand rather than use an electric tiller that has it's drawbacks. If you have people to help you, it is doable, and if you take your time it is doable. In my own garden, I 'loosen' the soil with a pitch fork, but I try not to actually 'turn it over'.

You could also do half the garden with one method and half with the other and find out for yourself which way works best for you. I've been reading books lately and getting a better understanding of what I'm trying to do when I think about improving my soil. I want to increase the organic matter, and the biological activity of the soil too, which should be largely responsible for reaching the other goals of improved water retention, fertility and good soil structure. So that has helped me to focus on where I should put the lion's share of my efforts.

I have some practical experience using lasagna methods and have seen wonderful results. I also did double digging in the long distant past. I lean toward permaculture methods. But some of the concepts about improving the soil in the garden are new to me, so if I have any errors in my presentation of that information, anyone jump in and correct me.

    Bookmark   February 1, 2014 at 11:34AM
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You may want to conduct a lead test despite the absence of painted homes. Leaded gasoline, used prior to 1970, is the main source of lead contamination. Especially in an old city like Philadelphia.

    Bookmark   February 2, 2014 at 10:10PM
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Keep in mind that Ma Nature has been making soil for eons, far longer then we have been, She takes whatever the mineral portion (the sand, silt, clay) in whatever proportion that is there and adds organic matter to that mineral portion. I have yet to see Ma Nature purchasing exotic materials to add and she grows the organic matter, every year.
The primary source of lead in soil is paint, although leaded gasoline has contributed some to that. Lead enters the body via inhalation (you breath it in as you work the soil) or ingestion (it is on you hands or food and you do not properly wash). Some places with high soil lead levels do recommend raised beds for growing foods to limit exposure when working the soil.
Tilling that compost in may be necessary, initially, but if due care is used and traffic across that planting bed is limited you may not need to till again.

    Bookmark   February 3, 2014 at 6:24AM
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I think I'm going to till. It just feels right to do it. My neighbor just volunteered to purchase and lend me tools for the job. That just saved me a lot of money (well I lot for me, I'm frugal) so I feel a bit better about buying compost.

I have a lot of free time so I don't mind something that is labor intensive as long as it's effective. Since I now have three pledeged volunteers I quite optimistic about the prospects. I'm planning on donating a majority of the produce to charity so I want to grow as much as possible. And I know I can easily give 30 hours a week or more just to getting soil ready before the last frost date. I cant wait for the snow to melt so I can get out there!

    Bookmark   February 9, 2014 at 12:23AM
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How about growing your own compost? Cover crops like clovers, blue lupines, birdsfoot trefoil add nitrogen and the roots help "till" the soil naturally. Grow your own brown matter with wheat or barley, flax or kenaf, and at the end of the year, chop it up and use it to suppress weeds while it decomposes, or mound it in piles to compost faster. A less immediate result, yes, but this will help to combat the years of weed seeds waiting just for you.

    Bookmark   February 14, 2014 at 3:35AM
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Just a random thought, an empty lot does not necessarily mean an unowned lot.
You can see whether the owner is paying taxes on that lot annually. If they are, it might be worth asking permission and asking about the plans for the lot.

Here is a link that might be useful: Property info

    Bookmark   February 14, 2014 at 6:59AM
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I am impressed with your initiative!

I agree with your decision to till or hand dig initially since removal of whatever was on the lot before it was vacant involved heavy equipment and compaction of the fill used. It can be difficult for plants' roots to penetrate highly compacted soils. Someone suggested that you pull topsoil/compost from your paths onto your beds; that's a good suggestion since you won't need to have good soil there.

A few random thoughts and suggestions:
- Having mulch of some kind, such as wood chips over corrugated cardboard in your paths will give a neat appearance, help conserve moisture, and reduce weeds.
- Having mulch such as compost on the surface of your beds after planting will help keep moisture and soil temperature more even as well as feeding the soil and plants.
- I notice that you are planning for 5' wide beds. I suggest that you reduce that to 4' wide so that you can easily reach to the middle of the bed from the paths. I am about 5 1/2' tall and DH is a couple inches under 6', and 4' width has worked well for us, allowing us to reach everything in the bed without having to walk on the soil.
- Being between brick buildings in the middle of a city, you will have something of a heat sink in the walls, so you may escape later spring and earlier autumn frosts, extending your season.
- Veggies need sun and sun angle will change over the course of the season. Start checking soon to see where the sun hits and for how long each day, and continue to check periodically as the season progresses. This will give you some idea where to best place the beds and the different veggies within the beds as some will be more tolerant of a bit of shade than others. Also take into account plant height and location in figuring shade for other plants.
- Since much of the produce is intended for a food pantry, talk to those who run it to find out what they will be most likely to find useful to their customers. Having produce that looks familiar (think about avoiding unusually colored varieties) and that is used locally will give you the biggest bang for your buck.
- Consider a couple of herbs if you have room and they will be used; basil and parsley are used in many different cuisines and tend to be expensive to buy. They can be dried or frozen for winter use.
- Have fun. The first year tends to be the most difficult, but having a veggie garden is also rewarding IME, both in terms of the produce, but also in terms of being outdoors watching the changes in the garden and the seasons.

    Bookmark   February 14, 2014 at 1:56PM
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seysonn(8a WA/HZ 1)

A lot of posts. I did not read them all.

What is topsoil ?: Naturally its is composted organic matter (mostly of plants origin) mixed with the ground underneath (Inorganic soil). Also, a well worked farmland or garden soil is considered topsoil.

So then you know how to make topsoil : Just till it(your navive ground) and add/mix in a lot of organic matter, simply compost. If you don.t have time to do it, just go to a nursery and have them deliver some that is already mixed and sold as garden soil.

    Bookmark   February 16, 2014 at 2:24AM
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From Merriam Webster dictionary, ": surface soil usually including the organic layer in which plants have most of their roots and which the farmer turns over in plowing".

Here is a link that might be useful: definition of topsoil

    Bookmark   February 16, 2014 at 6:20AM
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jbclem(z9b Topanga, Ca)

I'm glad to see someone mentioned planting cover crops. If you're only using half of the plot, plant the rest in cover crops. That can add nitrogen and vegetable matter to the soil, and some cover crops have strong deep tap roots that will open up the soil and also bring minerals up from the deep.

    Bookmark   February 19, 2014 at 6:38AM
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