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Super Green Thumb
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Joined: Mon Mar 23, 2009 5:59 pm
Location: TN. 50 years of gardening experience.

Why do plants grow so well in peat moss?

PEPPERS. I have noticed if I till a 3 cu ft bale of peat moss into my bell pepper row the plants grow very large they are typically 6 ft tall at the end of the growing season and bell peppers are 4 and 5 inch diameter. I want the soil to be about 50/50 peat moss and soil. If I grow the plants in soil along the pepper plants all stay very small sometimes they are only 1 ft tall by the end of the growing season and bell peppers are the size of golf balls. Compost helps but its not as good as peat moss. I have read peat moss makes the soil acid. Banana peppers are giant about the size of a real banana. Chili peppers like peat moss too. Do peppers like acid soil or do they have an easier time growing roots in soft soil?

HERBS. I have noticed if I till in a 3 cu ft bale of peat moss into my 4 x 8 herb garden all the herbs grow very large plants. I tilled in a large quantity of compost one year to compair what happens but peat moss always works best.

POTATOES. I tilled peat moss into the soil for potatoes but the potatoes don't seem to care. The crop was no different than usually.

TOMATOES. If I till a lot of peat moss into the soil my tomato plants grow 6 ft tall. I also seem to have more tomatoes with better flavor. I have tried plant compost but peat moss always works best.

Peat moss always seems to be much better than plant compost. Why do plants do so well in peat moss there must be something their they like?

The plants that like peat moss the best are peppers and herbs. The soil in TN is pretty bad, hard as stone in dry weather and very little organic material. I have had the soil tested many times they always say, add lime, organic material, manure, fertilizer, nitrogen. I always add a little lime especially to the tomatoes, organic material and sometimes a little 15/15/15 fertilizer. Manure is hard to get sometimes.

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Green Thumb
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Joined: Mon Mar 22, 2010 5:10 pm
Location: Sacramento, California

Well, from what I have heard, peat moss holds in moisture, so in your dry climate any help the plants are going to appreciate. Plus since you already stated your soil is very dry and lacking many nutrients the peat moss adds some of those and again helps retain moisture.

I used to live in TN, and never attempted gardening because the soil was just too hard to work and well, I didn't have ANY gardening knowledge as I do now :oops:

I remember I couldn't even get grass to grow!!!
Because all things need to be cherished
USDA zone 8A (guess it changed... not sure why I was a 9!)

Green Thumb
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Joined: Thu Jul 14, 2011 9:19 pm
Location: Pacific NW

Most likely the peat moss is creating more pockets for the water in the soil, ground up coconut husks (coir) would probably do the same and less stressful for the environment, if you can get it. It usually comes compressed and you have to rehydrate it first. Peat moss is essentially mined as it were.
Compost will help overtime in compacted, clay or clay like soil. Also, tilling is killing most of the earthworms and distroying the tilth of the soil, so what are we going to do.
As for the ph thing, it takes a long time to change the ph if you aren't using lime to raise it or sulfur to lower it and even then the changes can be short lived. Have you had your soil tested?

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Super Green Thumb
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Location: Northern Utah Zone 5

Peat moss is devoid of plant nurtients. It may help with the tilth of the soil and perhaps make the ph a little more acidic.
Gardening at 5000 feet elevation, zone 4/5 Northern Utah, Frost free from May 25 to September 8 +/-

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Greener Thumb
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Location: Los Angeles

Do any of the major chains carry coir? It's too bulky to ship affordably.
Sunset 23/USDA 11a, Elev. 783', Frost free since 8,000 BC. Plagued by squirrels, gophers, and peafowl, but coming to terms with it!

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Joined: Tue Jul 05, 2011 12:21 am
Location: Ontario Canada

Re: Why do plants grow so well in peat moss?

I've never heard of a 6 foot tall pepper plant.. I'll have to try that next year.

My tomatoes are around 8 feet tall now and they are just in my regular compost mix.

Green Thumb
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Joined: Thu Jul 14, 2011 9:19 pm
Location: Pacific NW

A soil scientist said I should have replied like this:
Tilling in peat most or coir, either into hardpan type soils like clay will loosen up the soil allowing the roots to grow faster, better, longer. This will allow the plant to better absorb water and the nutrients in the surrounding soil. The peat moss or coir will not add more nurtients and infact they are both very slow to decompose, therefore after several years it may not longer help much to till it in anymore, for a very long time.
This ability of the plant to quickly form a larger root mass, will benefit plants that grow mostly above the ground like tomatoes, eggplant, but not so much those that grow as root crops or tubers as they tend to be more shallowly rooted.
As to the issue of whether this will work for others, maybe if they have clay based soil and till enough of the peat moss in to make a difference. If you have loam, sandy loam probably not.
Note that in very sandy soil any organic matter that you add to soil will help it drain more slowly again giving the roots longer to absorb water, in the case of sand the roots grow through it just fine and the real benefit is water retention
I appologize for using the terms soil structure, tilth etc. If you were comfortable with those concepts you probably wouldn't have asked the question. The soil scientist is right, we over educated science nerds need to be more careful how we explain things.

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