Raised bed mix

creeker · January 2, 2017

I have built 2 raised beds 4ft x 16ft and 11inches deep. Now to fill them. I have oeat moss, Black Kow composted cow manure, lots of it cause it was on sale at
WalMart last fall at about half price. Also have a good sized pile of last year's semi composted leaves. What would you all suggest as a mix for growing greens, root crops and other garden plants other than tomatoes, peppers and okra. Will also be getting pecan shells. Do I need pearlite or vermiculite in the mix? All help appreciated. Ron

garyjr · January 3, 2017

I use pretty much the same mix as described. If not the Black Kow then local composted horse manure. I work close to a nursery supplier and purchase course vermiculite from them. Nice fluffy mix that works well for lettuce, spinach, carrots, onions and potatoes.. When starting a new bed I put down a layer of newspaper and semi composted leaves then add that mix on top. It will settle down throughout the season. Just top it off at the end of the season with more compost and mix in well in the spring.

creeker · January 3, 2017

Thanks Garyjr. What I am interested in is what proportions of each ingredient to use in the mix. Is one third each reasonable along with some minor ingredients or would you use more of one or two ingredients?

garyjr · January 4, 2017

I do 1/3 of each when starting a bed. This is essentially Mel's mix or the square foot gardening method. 1/3 variety of compost (yours, black kow, aged horse manure, etc) ,1/3 peat moss, and 1/3 coarse vermiculite. As I mentioned before this fluffy mix will settle by season end so top off with your favorite compost and some peat at the end of each season and mix in well come spring. With this mix you can retire your shovel and hoe.

creeker · January 4, 2017

Thank again, that answers my question.

creeker · January 4, 2017

Neither pearlite or vermiculite seem to be readily available in this area at this time of year and are pretty expensive, around $20 for 2 cubic feet. I'm wondering if crushed pecan shells could be substituted as part of the mix. It is $12/cu yard in bulk and I have the means to haul it. It would help with drainage if not water holding capacity. Any thoughts?

greenthumbomaha · January 4, 2017

This may not apply to your climate, but perlite has been discussed as floating to the top of the bed after a heavy rainfall. I have experienced this when I experimented and used a significant amount in a mix. Vermiculite not as much for me but I don't want too wet a mixture either. I often get downpours and it stays too wet.

I used a lot of the black cow in my new bed and it is good stuff but heavy when not well amended. You have a good start in your leaf pile. Many board members and extension agents also suggest mixing in shredded leaves for maintaining a fluffy mix, if you have the luxury of time and the right leaves. There are post suggesting which tree leaves to use and more importantly not to use, and the timing of application.

Can't help with the pecan shells. Cocoa shells stained the sidewalk if that is a concern near your beds.

- Lisa

Cole_Robbie · January 4, 2017

The pecan shells sound great. But I would try to find someone local who was using them in their garden with success. I would have a lot of concerns about PH, nitrogen fixing, and possible contaminants. The shells may serve you better as mulch.

The link below is from Texas and mentions they are very acidic, but that's good if you have alkaline soil
http://livingearth.net/pecan-shell-mulch

Gardeneer · January 5, 2017

If I had decent native soil I would add some of that too. I think adding perllite and vermiculite to raised bed is not an economical option and probably not necessary. Instead I recommend pine bark mulch ( finely crushed or very small nuggets ). It is better than peat moss (IMO) and it should cost less as well. Over the past 4 years I have built and filled close to 250 square foot of raised beds ( close to 7 cubic yard volume/fill). Most of the fill was garden mix , purchased by the yard. The rest was manure, compost, pine bark fine. And some native soil at the bottom.

Ricky Shaw · January 5, 2017

Timely thread, I'm bringing back a couple of raised beds this year. A lot of what I'll be working with is used promix, so I'm also needing ideas for better water retention.

AKmark · January 5, 2017

Ricky, I think your media drying out and your feeding program in combination is why you were so successful last year.
I don't mind anything drying out, then I can feed them, again, and again. Of course I don't actually let them dry out, instead I see opportunity.
What you need is two tanks, a pump, a timer, irrigation hose, a filter, a check valve, and drip emitters. Then keep feeding them like they are starving. Just sayin...

Ricky Shaw · January 5, 2017

Yes I'm happy with the promix and the chemgrow ferts in the fabric pots. They were so productive I don't need to plant as many, I'm going to 24 plants instead of 34. Something to add water retention is for the used promix I've half filled those raised beds with. Vermiculite would work well, but it's expensive. I've added 6 inches of leaves since those pics and will try to find some clean compost. The beds in the pic will be for squash and cukes.

Your right though Mark, I do need to look into a good two-tank fertigation system.

AKmark · January 5, 2017

Two tanks will save you the high cost of dosatrons, and they will empty at the same rate when plumbed together.

Cole_Robbie · January 5, 2017

What's the rationale for the $400 Dosatron over the $40 Mazzei? Is it that you can control the strength of the mixture more easily? Do Dosatrons work at a wider range of flow rates? Mazzei injectors are cheap, but they only work within a narrow range of flow rate.

With my drip tape, my high tunnel is 1.5 GPM when just only it is being irrigated, but when I turn on everything, it is 9 GPM. I still haven't found an injector that will work at both of those rates.

AKmark · January 5, 2017

Cole, they work perfectly at different flow rates, they are also very precise. Mine operate at up to 20GPM, so I can do several stations at once. I think I can do 570 drip emitters at once if they are 3.2 GPH. Most of my friends use dosamatics, and have different feed lines to deliver CaNO3. I went with dosatron, because that's what our state agronomist told me to do, and they are what they use.
I can control ratios very easily, yes, but have mine set at 100-1 which makes it easy math to calibrate them.
I am in this for the long haul, and have not had good luck with cheap anything, I hate replacing stuff.

January 2, 2017	#1
creeker Tomatovillian™ Join Date: Dec 2015 Location: Southern New Mexico Posts: 106	Raised bed mix I have built 2 raised beds 4ft x 16ft and 11inches deep. Now to fill them. I have oeat moss, Black Kow composted cow manure, lots of it cause it was on sale at WalMart last fall at about half price. Also have a good sized pile of last year's semi composted leaves. What would you all suggest as a mix for growing greens, root crops and other garden plants other than tomatoes, peppers and okra. Will also be getting pecan shells. Do I need pearlite or vermiculite in the mix? All help appreciated. Ron

January 3, 2017	#2
garyjr Tomatovillian™ Join Date: Mar 2016 Location: Mechanicsville, VA zone 7a Posts: 97	I use pretty much the same mix as described. If not the Black Kow then local composted horse manure. I work close to a nursery supplier and purchase course vermiculite from them. Nice fluffy mix that works well for lettuce, spinach, carrots, onions and potatoes.. When starting a new bed I put down a layer of newspaper and semi composted leaves then add that mix on top. It will settle down throughout the season. Just top it off at the end of the season with more compost and mix in well in the spring. __________________ "The task of the modern educator is not to cut down jungles but to irrigate deserts." C.S. Lewis

January 4, 2017	#4
garyjr Tomatovillian™ Join Date: Mar 2016 Location: Mechanicsville, VA zone 7a Posts: 97	I do 1/3 of each when starting a bed. This is essentially Mel's mix or the square foot gardening method. 1/3 variety of compost (yours, black kow, aged horse manure, etc) ,1/3 peat moss, and 1/3 coarse vermiculite. As I mentioned before this fluffy mix will settle by season end so top off with your favorite compost and some peat at the end of each season and mix in well come spring. With this mix you can retire your shovel and hoe. __________________ "The task of the modern educator is not to cut down jungles but to irrigate deserts." C.S. Lewis

January 5, 2017	#9
Gardeneer Tomatovillian™ Join Date: Feb 2015 Location: NC - zone 8a - heat zone 7 Posts: 4,916	If I had decent native soil I would add some of that too. I think adding perllite and vermiculite to raised bed is not an economical option and probably not necessary. Instead I recommend pine bark mulch ( finely crushed or very small nuggets ). It is better than peat moss (IMO) and it should cost less as well. Over the past 4 years I have built and filled close to 250 square foot of raised beds ( close to 7 cubic yard volume/fill). Most of the fill was garden mix , purchased by the yard. The rest was manure, compost, pine bark fine. And some native soil at the bottom. __________________ Gardeneer Happy Gardening !

January 4, 2017	#7
greenthumbomaha Tomatovillian™ Join Date: Nov 2011 Location: Omaha Zone 5 Posts: 2,514	This may not apply to your climate, but perlite has been discussed as floating to the top of the bed after a heavy rainfall. I have experienced this when I experimented and used a significant amount in a mix. Vermiculite not as much for me but I don't want too wet a mixture either. I often get downpours and it stays too wet. I used a lot of the black cow in my new bed and it is good stuff but heavy when not well amended. You have a good start in your leaf pile. Many board members and extension agents also suggest mixing in shredded leaves for maintaining a fluffy mix, if you have the luxury of time and the right leaves. There are post suggesting which tree leaves to use and more importantly not to use, and the timing of application. Can't help with the pecan shells. Cocoa shells stained the sidewalk if that is a concern near your beds. - Lisa

January 4, 2017	#8
Cole_Robbie Tomatovillian™ Join Date: Jun 2012 Location: Illinois, zone 6 Posts: 8,407	The pecan shells sound great. But I would try to find someone local who was using them in their garden with success. I would have a lot of concerns about PH, nitrogen fixing, and possible contaminants. The shells may serve you better as mulch. The link below is from Texas and mentions they are very acidic, but that's good if you have alkaline soil http://livingearth.net/pecan-shell-mulch

January 5, 2017	#11
AKmark Tomatovillian™ Join Date: Jun 2013 Location: Wasilla Alaska Posts: 2,010	Ricky, I think your media drying out and your feeding program in combination is why you were so successful last year. I don't mind anything drying out, then I can feed them, again, and again. Of course I don't actually let them dry out, instead I see opportunity. What you need is two tanks, a pump, a timer, irrigation hose, a filter, a check valve, and drip emitters. Then keep feeding them like they are starving. Just sayin...

January 5, 2017	#12
Ricky Shaw Tomatovillian™ Join Date: Aug 2015 Location: Zone 6a Denver North Metro Posts: 1,910	Yes I'm happy with the promix and the chemgrow ferts in the fabric pots. They were so productive I don't need to plant as many, I'm going to 24 plants instead of 34. Something to add water retention is for the used promix I've half filled those raised beds with. Vermiculite would work well, but it's expensive. I've added 6 inches of leaves since those pics and will try to find some clean compost. The beds in the pic will be for squash and cukes. Your right though Mark, I do need to look into a good two-tank fertigation system.