What is the best combination to fill a raised bed

Poll ended at Sun Jan 20, 2013 11:22 am

100% compost
20%
2
33%peat 33% sand or perlite 33% compost
10%
1
20% compost 50%native soil 15% peat 15% sand or perlite
40%
4
25% Peat 25% Perlite 20% compost 30% native soil
20%
2
50% Peat 50% Perlite + fertilizer (your choice)
10%
1
 
Total votes: 10
imafan26
Mod
Posts: 11439
Joined: Tue Jan 01, 2013 1:32 pm
Location: hawaii, zone 12a 587 ft elev.

What is the best planting mix?

I have read a lot of things about the best mix for a raised bed.
Some people believe even in pots there should always be some soil in it.
Everything from 100% compost to varying combinations of peat/sand or perlite/compost have been recommended. What is your optimum mix?

I've planted in mostly compost from derived from city greenwaste
It did fine for cabbages and root crops but not so much for acid loving plants.
Tested compost pH 7.8 high Phos, high K. Needed supplemental N. Plants were short but healthy
Peatlite (50% peat,50% perlite- my basic mix for all pots works for most things. Needs supplemental fertilizer.
60% native soil (mostly red clay) 15% cinder and perlite for drainage and the rest redwood compost, organic compost, and peat moss. Slow release, granular and water soluble fertilizers ( I use citrus fertilizer the most).
Tomatoes, cabbage and greens are big and productive. Root crops taro, beets, daikon produce mostly tops. I have been told I have too much nitrogen and it is probably true. I need to find a mix of amendments and fertilizer that works for both my greens and my roots. My philosophy is to be as organic as is practical, but I don't have any issues with using commercial fertilizer. I use vermicast when it is available, but I do not use manures anymore. I would have to forgo planting for 120 days or plant a green manure instead of vegetables if I used manure.
Happy gardening in Hawaii. Gardens are where people grow.

User avatar
jal_ut
Super Green Thumb
Posts: 7480
Joined: Mon Jan 19, 2009 3:20 am
Location: Northern Utah Zone 5

I chose your third choice that was heavy on native soil.

I am sorry, but peat, and perlite may serve to anchor roots, but are devoid of nutrients.

Compost is a good soil amendment and full of nutrients, however too hot to be used alone.
Gardening at 5000 feet elevation, zone 4/5 Northern Utah, Frost free from May 25 to September 8 +/-

DoubleDogFarm
Super Green Thumb
Posts: 6113
Joined: Mon Mar 29, 2010 3:43 am

75% native soil
25% Compost

Eric

User avatar
ReptileAddiction
Greener Thumb
Posts: 866
Joined: Sun Jun 17, 2012 4:52 am
Location: Southern California

I have been watching the videos of a man who has thousands of square feet of raised bed space and fills all his beds with 100% compost. He has one of the most productive gardens I have ever seen. He did mix in rock dust with every plant so that probably helped.

On a side note I am against using peat moss because it is a non renewable resource (and it is acidic). I don't not use anything with peat moss in it but I generally try to avoid using it. I certainly wouldn't use it in any major amount filling a bed.

User avatar
rainbowgardener
Super Green Thumb
Posts: 25303
Joined: Sun Feb 15, 2009 11:04 pm
Location: TN/GA 7b

Yeah, I would suggest coconut coir instead of peat moss.

I'm sure different composts are different. I would not use pure compost for a raised bed, because mine tends to be too heavy and dense. Over time it would compact.

Some combination of about half native soil, with compost, aged composted manure, coconut coir, a little bit of perlite, and whatever other organics you have around. I put a bunch of fall leaves in mine, because that is what I had.
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

User avatar
applestar
Mod
Posts: 28047
Joined: Thu May 01, 2008 11:21 pm
Location: Zone 6, NJ (3/M)4/E ~ 10/M

I had trouble choosing from the options so I didn't vote.

If this is raised bed directly on the ground, I prefer sheet mulching/lasagna bed style with a bit of hugelkultur concept thrown in. I also like the idea of scraping sod and topsoil from the paths down to subsoil and tossing the good stuff on the raised bed.

I haven't actually tried burying entire logs, but the bed I made by burying wrist-arm size branches as well as all the sticks and leaves turned out very well. Fall leaves, straw, hay, weeds, garden waste, alfalfa pellets, mushroom compost, own homemade compost, coffee grounds, bagged manure, bokashi, sand (I have clay subsoil), rockphosphate, greensand, lime.... All piled up on top of existing lawn poked full of holes as deep as garden fork would go. Weedy/weed seed suspect materials covered with cardboard, then piled with non-weedy materials. I don't add peat, coir, or perlite/vermiculite.

This season, I'm going to test hugelkulture some more. I have an area that gets very soggy during spring thaw. I want to build this area up a bit. Initially thinking I want to get a lot of sand and topsoil in there, I had been stumped (:P) about buying sufficient material. But someone recently reminded me about hugelkultur, and I happen to have a bunch of rotting tree stumps (:wink:) that need to be disposed of, as well as a woodpile that could use some cleanup. So hopefully I have enough material to bury. 8)

User avatar
ReptileAddiction
Greener Thumb
Posts: 866
Joined: Sun Jun 17, 2012 4:52 am
Location: Southern California

I am sure the ratio of browns to greens in your compost is what makes it more dense or less dense. Coconut coir is pretty much worthless except to loosen soils. I use it in reptile cages all the time.It is basically void of nutrients. Btw what is hugelkultur?

I did some research on hugelkutur and it is very interesting. That is the first time I have heard of it. What I do not understand is after a couple years they turn into basically compost. Couldn't you just build a huge bed like that out of compost and native so?

User avatar
applestar
Mod
Posts: 28047
Joined: Thu May 01, 2008 11:21 pm
Location: Zone 6, NJ (3/M)4/E ~ 10/M

My in-a-nutshell understanding of hugelkultur is that the technique initially and quickly creates a tremendous mycorrhyzae incubator which will set down a mycelium mat over a large area over time and establishes a network of soil foodweb. It is also a way to sequester carbon which left above ground will eventually find their way into the atmosphere, and it becomes a long-term carbon bank that lasts much longer than compost.

Hopefully other members here who have been doing this on large scale already will give us a little more insight, but we have several threads on the subject in the Permaculture Forum :wink:

DoubleDogFarm
Super Green Thumb
Posts: 6113
Joined: Mon Mar 29, 2010 3:43 am

I did some research on hugelkutur and it is very interesting. That is the first time I have heard of it. What I do not understand is after a couple years they turn into basically compost. Couldn't you just build a huge bed like that out of compost and native so?
Maybe, Do you have a large supply of cheap compost. Most hugelkultur systems are built from forestry slash. Debris leftover from logging. It already on site and they found a good use for it. Traditionally it was burned.

Hugelkultur berms are big sponges that require little water if any.

Eric

User avatar
digitS'
Super Green Thumb
Posts: 3562
Joined: Sun Sep 26, 2010 5:10 pm
Location: ID/Wa! border

"Tested compost pH 7.8 . . ."

Wow! I am surprised that it is so high! Where are the humic acids in that compost? And, about that redwood compost and the fir mulch you mentioned in the other thread -- now I know where our West Coast organic material is going :wink: !

Anyway, with very much compost in the mix there will be a very important need to replace what is in the beds probably on a yearly basis. I'm not terribly happy with even a 1/3rd soil mix and the 3-way mix they sell around here (1:1:1, compost:soil:sand) seems like just a recipe for sandy soil to me.

Of course, it depends on your native soil and, in general, the more organic matter in there the better but it might get to be something like shoveling sand against the tide. Only, it is shoveling organic material against decay.

I quite often make my own potting soil with equal amounts of soil, compost and peat, with a shovel or 2 of perlite in each wheelbarrow. This is for the larger pots of perennials. The plants will only stay in those pots for a year or 2 without re-potting.

Hugelkultur? I once asked a Southeast Asian farmer why he didn't bury his trees instead of burning them . . . He looked at me like I was out of my mind. I tried to imagine bringing in a backhoe to a place that didn't even have hand shovels. Actual weeding often involved an awful lot of burying the weeds with heavy hoes. THAT seemed like a good idea.

Steve
We are each other's harvest; we are each other's business; we are each other's magnitude and bond. ~ Gwendolyn Brooks

imafan26
Mod
Posts: 11439
Joined: Tue Jan 01, 2013 1:32 pm
Location: hawaii, zone 12a 587 ft elev.

Thanks everyone for your input. I think I'll try adding more organics and compost. My soil is heavy clay in my home garden with < 1" of compost added with each planting. I may be watering too much, so I will try to back off watering...once the rain stops. I water nearly everyday. I will retest my soil again it has been awhile. I'll back off on peat moss a bit. I'll try some sort of mulch to retain surface moisture. This garden is slightly acidic and is good for greens, tomatoes, peppers, eggplant. Not so much for root crops.

As for the other garden locations. Alkaline conditions prevail, but they are good for cabbages, and root crops. I will add sulfur and nitrogen there. These plots had hefty amounts of compost and I thought the compost actually was causing the alkaline problem and why tomatoes do poorly there.
:P
Happy gardening in Hawaii. Gardens are where people grow.

User avatar
rainbowgardener
Super Green Thumb
Posts: 25303
Joined: Sun Feb 15, 2009 11:04 pm
Location: TN/GA 7b

I water nearly everyday.

Definitely too much, especially in a humid climate. You will do much better to water deeply but less often. I water once a week- ish (depending on the plant, weather, etc) IF there has been no significant rain.
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
Mod
Posts: 11439
Joined: Tue Jan 01, 2013 1:32 pm
Location: hawaii, zone 12a 587 ft elev.

Thanks rainbow. I water more out of habit. The top of the soil in my home garden(500ft, 16 in./yr rain) does get crusty, so I think more compost and mulch will help that. It actually takes a long time to dry when it is wet

One of my alkaline plots is actually in a high rainfall area(827ft, 20 inches a year), I water it once a week (for an hour) at most. Mostly it lives on rain

The second alkaline garden is in opposite conditions. That is where the soil tested pH 7.8. it is on a sprinkler system, very short 3 min twice a day. 17 ft above sea level. When it rains hard, it floods. Otherwise ave 8 inches a year.
Very poorly drained. Phythoptera is a problem. Deep rooted, acidic and heat intolerant plants just don't survive. 9-14 degrees warmer than the other 2 gardens.
Happy gardening in Hawaii. Gardens are where people grow.

User avatar
rainbowgardener
Super Green Thumb
Posts: 25303
Joined: Sun Feb 15, 2009 11:04 pm
Location: TN/GA 7b

Interesting. I think of Hawaii as being very high rainfall. But where I am, in an ordinary year we get 40 inches of rain.
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

Bobberman
Super Green Thumb
Posts: 2437
Joined: Tue Nov 16, 2010 3:31 am
Location: Latrobe Pa.

Raied beds or cold frames I like to put something a foot down that will decompose over a few months. i even like to add a little fertilizer down deep like bloodmeal or just about anthing even leaves! I cover it with strained garden soil since straining takes ut alot of the grass roots! I even mix things in as I strain like maybe a bag of bought rganic compost or anything you have on stock will work!
+++
Sand is one of the best especially river and. The top layer I like about 2 inches of bught top soil or a good compost with no weeds! As the season progresses the roots will get down to the composted material at the bottom. I also like dirt from under pine trees mixed in with the strained garden soil! Try some shredded paper at the bottom of the raised bed or a layer of straw!
I enjoy fishing ,gardening and a solar greenhouse! carpet installation repair and sales for over 45 years! I am the inventor of the Bobber With A Brain - Fishing Bobber!

imafan26
Mod
Posts: 11439
Joined: Tue Jan 01, 2013 1:32 pm
Location: hawaii, zone 12a 587 ft elev.

We have mostly sunny days with light rain. A bad day is when it rains all day.
Most of the rain falls on the windward sides of all the islands and in the mountains. The Koolau's get 200 inches of rain a year, so that is where most of our water comes from.
I live in the high central plain created by lava from the two main volcanoes that created the island. It is cooler than the lowlands and relatively wet compared to the dry leeward side.
Except for the garden near sea level, the other plots drain well and subside in a few hours even after flooding rain.
The garden at sea level is in a flood zone and will stay flooded for days. I think I might do more research on hugelkultur. There are logs, tree trimmings, and compost available at that garden to make it work.
Happy gardening in Hawaii. Gardens are where people grow.

User avatar
digitS'
Super Green Thumb
Posts: 3562
Joined: Sun Sep 26, 2010 5:10 pm
Location: ID/Wa! border

Semi-arid conditions on a tropical island where mountains catch an enormous amount of the rainfall !! The Koolau Range on Oahu is there in dark blue:

Image
Giambelluca, T.W., Q. Chen, A.G. Frazier, J.P. Price, Y.-L. Chen, P.-S. Chu, J.K. Eischeid, and D.M. Delparte, 2012: Online Rainfall Atlas of Hawai‘i. Bull. Amer. Meteor. Soc., doi: 10.1175/BAMS-D-11-00228.1.

I garden in a semi-arid location with less than 20" of precipitation each year but much of that falls as winter snow . . .

Interesting contrast & similarity :)

Steve
We are each other's harvest; we are each other's business; we are each other's magnitude and bond. ~ Gwendolyn Brooks

imafan26
Mod
Posts: 11439
Joined: Tue Jan 01, 2013 1:32 pm
Location: hawaii, zone 12a 587 ft elev.

It actually is not that arid. There is a marked difference between the green and lush windward side and the dry leeward side. Most of the wild plants, have adapted, they will dry and look almost dead but will green up with just one good rain.
I just realized a problem with Hugelkultur. Termites! Buried wood is an open invitation and they will also eat woody plants and sweet potatoes.
Most native tropical cultures just cut down a part of the forest for crops. When the land was no longer productive and nearby resources became scarce, they moved to another part of the forest. Composting was done by the forest. They did not have metal tools until after the western ships arrived to cut down large trees. Plantations learned the hard way that native trees don't come back after being cut. When the rains came the soil washed away.
Wherever you garden, you need to take into account practices that are in harmony with the whole ecosystem.
Happy gardening in Hawaii. Gardens are where people grow.

Return to “Vegetable Gardening Forum”