jimjabadoojr
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Good substitute for soil

I'm starting to build a raised garden bed which is approx 3.6x.9x.9 meters (11.81x2.9x2.9 feet).

I have some soil but not enough to fill it, i am wondering what else i can use.

Leaves, small branches, mulch, kitchen scraps etc.

Is there anything im missing?

I will look in the local classifieds to get the soil i need but if i have more options it will be faster

Thanks in advance

imafan26
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Location: hawaii, zone 12a 587 ft elev.

Re: Good substitute for soil

You can screen your topsoil if it is of good quality and mix it with an equal portion of screened compost from multiple sources (kitchen waste, mushroom compost, humic acids, composted manure)

You can use Mel's Mix (soil less)
1/3 peat moss
1/3 compost (good quality made from a variety of sources and not "forest products" from sawmills)
1/3 vermiculite
Peat moss and vermiculite can be purchased in 3.8 or 4 cu ft bags at local agricultural suppliers. Fertilizer is not included

If you have the time. Start the raised bed in the fall by building a lasagna bed. Essentially one big compost pile. If you want to plant sooner you can used bagged potting soil for the top 4 inches but plant low nutrient users first not the hungry high users. More compost and fertilizer will have to be added and the compost will use some of the nitrogen as it decays. The nutrients from the compost will take 6 months to 2 years to fully release.
https://extension.oregonstate.edu/lane/s ... 2015_0.pdf
https://www.growgreatvegetables.com/fert ... egetables/

When you are done give it some time to settle out to blend and compost sinks as it decomposes. Get a soil test to get fertilizer recommendations. Ask for organic if you want organic recommendations.
Happy gardening in Hawaii. Gardens are where people grow.

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rainbowgardener
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Re: Good substitute for soil

The leaves and kitchen scraps make a good compost pile. Until broken down, they don't make a particularly good soil to plant in.

One 11x3 bed isn't that big. Where I am you can buy things like compost, topsoil, etc by the cubic yard or truckload. It is WAY cheaper that way than buying bags. Three feet deep is a LOT. Is there a reason you are making it that deep? It certainly adds to the amount of soil/ compost etc you need to buy. Unless you are doing that to make it handicap accessible, half that deep would be plenty.
Twitter account I manage for local Sierra Club: https://twitter.com/CherokeeGroupSC Facebook page I manage for them: https://www.facebook.com/groups/65310596576/ Come and find me and lots of great information, inspiration

imafan26
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Re: Good substitute for soil

Agreed. I do green manure with kitchen scraps but mostly soft things like leaves and eggshells. I freeze it first so it breaks down faster and it takes a while for me to collect enough. I dig a hole in the soil about 18 inches deep and trench compost the kitchen waste and maybe some yard greens that have been chopped up. I avoid meat waste. Bury the trench and I usually have to cover it with a board or pots on a board for a couple of weeks. It keeps the mongoose from digging it up for the grubs. The soil will sink as the vegetable mass loses water then I can remove the board and level the top.

I probably should clarify the earlier post. The compost that is mixed with the soil should come from a variety of sources not one like "forest products". Compost sources should be from at least 5 sources like kitchen waste, mushroom compost, composted manure, leaves, garden waste (non diseased plants). I did not mean for the raw materials to be used but the sifted compost made from a variety of sources like the ones mentioned.

Making your own is best but it means planning at least 6 months ahead and starting a compost first.
Buying in bulk is a good option.
You can get manures from farms and stables but they will need to be composted first or nothing can be harvested for 120 days from the time the fresh manure is added because of pathogens that can be in the manure. Manures are also high in salt
You can get a truckload of chipped greenwaste if you ask the local landscapers to drop a load when they are in the area. Most would be glad to do that to avoid the cost of hauling it away and the tipping fees.
You can get a truckload of compost and other materials like sand, topsoil at some greenwaste facilities. It is usually cheaper if you pick it up. The trucking fee costs more than the product.

A bed that is 18 inches deep would be sufficient for most plants and require half the fill. Unless you are doing hugulkultur then you could fill the lower part of the beds with rotting logs which will decay over time.
https://richsoil.com/hugelkultur/
Happy gardening in Hawaii. Gardens are where people grow.

jimjabadoojr
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Re: Good substitute for soil

Thanks for the info, ideas and the resources on hugelkultur

I understand that it is quite high for a raised garden bed. I don't really want to be on my knees doing this. And i'd rather it be out of the way of kids, pets etc, that's why it's so high. It's about the height of a kitchen bench

I've built the frame and i am cladding it now with some spare time that I have

I happened to have a few logs lying around that i was going to throw into the fire. I think i might throw a few in the garden bed a la hugelkultur.

Might even do a bit at a time.

So if I understand correctly:

- I can put quite a few things in as long as there is a mix of compost sources. i.e. kitchen scraps, manure, leaves etc. ?
- Fresh manure requires time to break down before using it as compost, so maybe avoid the raw type
- Ring up greenwaste facilities to see what they provide as far as topsoil is concerned
- Take time with it

It's autumn here now where I am (Australia) so i figure it's a good time to get started

Ill keep this updated

jimjabadoojr
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Joined: Thu Apr 06, 2017 6:22 am

Re: Good substitute for soil

So i finished my garden bed and filled it with plastic
I've even thrown some newspaper on the bottom (although i don't think it will do anything) and some leaves and small branches

Now onto finding some soil

Ill post pictures in a few days when i get a chance

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rainbowgardener
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Re: Good substitute for soil

Umm... filled it with plastic?? ? :shock: :?: :eek: why?

You started by asking about a "substitute for soil." Plastic is in no sense a substitute for soil. It will not break down in the next thousand years or so, but many plastics do leach out toxins.
Twitter account I manage for local Sierra Club: https://twitter.com/CherokeeGroupSC Facebook page I manage for them: https://www.facebook.com/groups/65310596576/ Come and find me and lots of great information, inspiration

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