vnmjohnson
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Raised bed vegetable garden with half mushroom compost

We are building 4 raised vegetable gardens, each are 16'x4'x18". I think we'll use half mushroom
compost (straw, peat moss, chicken manure, cottonseed meal, soybean meal, gypsum and lime. PH=6.8 )
and half 4 way soil (a mixture of topsoil, Composted cow manure, yard debris compost and sand). This
is our first attempt at a garden. Can anyone tell me if we are on the right track with this soil combo?
We are growing tomatoes, peppers (hot and sweet), onions, carrots, zucchini, eggplant, and herbs.
We have about 200 plants started! I know that's a lot, but I had no idea EVERYTHING would germinate. Completely new at this! :shock: :shock: :shock:

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rainbowgardener
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Soil mix doesn't sound bad, but a bit rich and heavy/dense -topsoil, manure, two kinds of compost. It may tend to compact in your beds, which is not good, because it shuts out air and water. The sand (coarse sand!) is a good addition. You might think about some peat moss or coconut coir as well to help keep it lighter and fluffier.

256 sq ft of veggie beds is a lot to start with when you are brand new at it. Don't crowd your beds. You will probably have to cull your herd of seedlings a bit. You will be better off only planting the strongest ones. By not crowding, you give them better conditions and reduce your work.

Once everything is planted and growing, MULCH!!! For veggies, I like to do a mixed "brown" and "green" mulch with grass clippings, fall leaves, pulled weeds, sometimes straw, mixed or layered. But you can use pine straw, wood chips, shredded paper, or whatever organics you have handy. A 3-4" thick layer of mulch over everything will save you a ton of work in watering (conserves soil moisture) and weeding.

Then start your compost pile, so you won't have to keep buying compost. Homemade compost is the best! If you aren't familiar with composting, read the basics and 101 threads at the top of the Compost Forum.

Welcome to helpfulgardener and the wonderful world of homegrown veggies!!!

vnmjohnson
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Thank you so much, Rainbow Gardener! That was so helpful!!! I'm going to read the space instructions for each plant. If there isn't room for the herbs, they may just be planted in the ground around the edge of the forest. Hopefully if I plant enough of them in enough different places the deer wont eat them before we can enjoy a few.

I would not have known about the mulching part. OMG...that could have been disastrous. Then again, it is just one grand experiment this year. We are going to get a chipper and chip the yard debris from the fall winds--we have a LOT of it. We are going to use it to mulch around some stands of trees. Any chance this would also work as mulch for the garden? It is made up mostly of evergreens--cedar, fir, pine. And we are in the Pac NW, with a rain forest leading to our living area...so moss.

Thank you so much!!!

imafan26
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Your pH is 6.8, why are you adding, chicken manure and lime? The mushroom compost is also alkaline. The peat moss is
acidic but if you are adding so much base, then it won't be much of an offset. Gypsum would not be needed unless you have a saline sodic soil. If you are doing a raised bed the soil is not compacted. Gypsum is often used to make breaking through compacted clay soil easier and lime and chicken manure have calcium, so you should not need both gypsum and lime. Chicken manure can raise pH by as much as 0.5 higher.

https://fabe.osu.edu/sites/fabe/files/I'm ... lletin.pdf

vnmjohnson
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Thanks for your reply, imafan. The ph 6.8 was the ph for the mushroom compost not my garden. I don't have any dirt in the raised beds at all yet. I'm trying to figure out what to put in it. Do you have a suggestion as to what to fill them with?

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rainbowgardener
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I think the gypsum and lime were not separate additions, but just components of the mushroom compost:

"The recipe for mushroom compost varies from company to company, but can include composted wheat or rye straw, peat moss, used horse bedding straw, chicken manure, cottonseed or canola meal, grape crushings from wineries, soybean meal, potash, gypsum, urea, ammonium nitrate and lime." https://extension.oregonstate.edu/garden ... -carefully

If the pH of the mushroom compost is 6.8, just south of neutral, then there is not so much of the gypsum and lime to make it alkaline. I use mushroom compost as a basic ingredient in my homemade potting soil and I like it for the texture. But I find that it is not very high in nitrogen. The composted cow manure in your 4 way soil will be important. I don't know what the proportions of the ingredients in that are. If it isn't real high in the composted manure, you might need to add more or more composted poultry manure or other N sources like alfalfa meal, fish meal, etc.

vnmjohnson
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Thanks again, Rainbow gardener!

imafan26
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Thanks for the clarification.

I used to use mushroom compost, but I also limed every two years. These were the days before I even knew about how to get a soil test done. I just assumed the soil would get more acidic because of the acidic fertilizer I was using (miracle grow every two weeks). After a few years, Okra, which had no problem growing got smaller and to the point where I couldn't even germinate it. Cabbages did fine and actually liked it.

By adding lime as a routine rather then when needed, I crept the pH up to the point where the alkaline cabbages were the only things that was happy there. It took years before I could grow anything acid loving there again.

Blood meal would be higher nitrogen if you want organic, but it is expensive unless you can get it from a slaughterhouse.
You don't really need to add a lot of nitrogen in the beginning, nitrogen is very volatile and best to apply in 2 or three applications over the life of the plant. You can also increase the nitrogen if you plant a green manure like inoculated cow peas first to help give the following crop additional nitrogen.

Fish emulsion and manure teas can help with nitrogen and if you are doing organic you will need to supplement since it will take a while for the garden to build up the soil organisms to make conversion efficient.

I I were building a new bed, I would still do a lasagna bed as it would be the most cost effective way to do it. Only the top 4 inches would need to be good topsoil to plant. Lasagna beds are better put together in the fall so they would be ready for Spring planting.

I don't know about where you live, but at the local composting facility they do sell a special mix for raised beds it contains compost, topsoil, manure, and cinders. Sand would be better but cinders are cheaper here and provide good drainage but some people do not like it for root crops. It is also cheap by our standards. If you have a 1/2 ton truck and go to the facility it was $38 for a truckload and it was enough to fill a 4ft x 8ft x 8in raised bed.

vnmjohnson
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Thank you Imafan. We found a local supplier in Washington, where we are, that has a mix they say is especially for PacNW gardens. I don't know what's in it yet. Will visit them this week. They don't have a website. Well they do, but it's limited. Doesn't list products. I'm going to go there and check it out this week. All the information you and Rainbow gardener have given me will help me make the right choice for here. We just bought this place in October, so there was no time to plan ahead and I can't bear to wait until next spring, so we'll just see what we can do first year out. : ) Must be nice gardening in Hawaii--all that sun. I still have to be careful of a sudden freeze overnight until May. But, that's why I have started them under grow lights.



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