Need Advice on Soil Mix for New Raised Beds

[gtaus]

Hoping someone before me has solved this issue. In the past, I always filled my raised beds with Mel's Square Foot Garden mix of 1/3 compost, 1/3 peat moss, and 1/3 vermiculite. However, nobody around here sells the big 3 cubic foot bags of vermiculite anymore. The big box stores used to carry the stuff and it was not too expensive, about $18 per 3 cubic feet. I am not going to buy a small bag of the stuff for $$$ because it would just cost way too much for a raised bed, about $96 for 3 cubic foot equivalent. I know perlite can be substituted for vermiculite, they are similar, but not the same, and I know the difference. Unfortunately, perlite is no longer available in the big bags either. So what to do?

I called a local nursery and talked to the owner. He suggested, given the fact that we no longer can get bulk vermiculite or perlite, I should just use 1/2 compost, and 1/2 topsoil, and call it good.

I'm just a struggling gardener, and I don't know much about anything. Would anyone please advise me on what mix they use for raised beds today given that vermiculite and perlite are no longer available in bulk bags? Thanks is advance for any help.

 

[Acre4Me]

Hmmm...we’ve ordered the big bags of both, but haven’t checked this year. For my raised beds, I’m dealing with a lot of clay soil. So, we’ve added coarse sand, perlite, vermiculite, gypsum, sulfur (we have high pH), peat moss, and top soil. We’ve grown cover crops to turn under to rot. We are just now getting compost, so that will be a new add. We have added manure when we can get it, which isn’t very often. We basically add what we can get that makes sense. I have 11 raised beds and one really large “raised bed”. The 11 raised beds with wood sides total about 500-600 sq ft. The big single bed is about 600 sq. Ft.

 

[Percheron chick]

How tall are the beds? You only need 8-12" of good soil for the beds. You can fill the bottom with organic material that over the next year will break down and become available for subsequent plantings. Cardboard, newspaper, sticks, straw, leaves, unfinished compost, even junky native soil. All free plus you get something out of what one would consider trash. 1/2 compost and 1/2 topsoil is more than good to get up and running. Not a fan of peat because it really doesn't add much to the soil other than moisture retention. Compost will hold moisture plus offer valuable nutrients to the soil. Don't over think it. Good soil takes years to get just right. Over the summer you will be mulching and adding fresh compost. By the fall, it will be nicely broken down. You will turn it over, add some hot chicken poop, leaves and whatever else you want, let it sit over the winter, turn it again and start a new season.

 

[roosterhavoc]

Hoping someone before me has solved this issue. In the past, I always filled my raised beds with Mel's Square Foot Garden mix of 1/3 compost, 1/3 peat moss, and 1/3 vermiculite. However, nobody around here sells the big 3 cubic foot bags of vermiculite anymore. The big box stores used to carry the stuff and it was not too expensive, about $18 per 3 cubic feet. I am not going to buy a small bag of the stuff for $$$ because it would just cost way too much for a raised bed, about $96 for 3 cubic foot equivalent. I know perlite can be substituted for vermiculite, they are similar, but not the same, and I know the difference. Unfortunately, perlite is no longer available in the big bags either. So what to do?

I called a local nursery and talked to the owner. He suggested, given the fact that we no longer can get bulk vermiculite or perlite, I should just use 1/2 compost, and 1/2 topsoil, and call it good.

I'm just a struggling gardener, and I don't know much about anything. Would anyone please advise me on what mix they use for raised beds today given that vermiculite and perlite are no longer available in bulk bags? Thanks is advance for any help.

1/3 compost, 1/3 top soil and 1/3 mycorrhiza pro mix (plenty of perlite in the pro mix for raised beds)

 

[gtaus]

Hmmm...we’ve ordered the big bags of both, but haven’t checked this year.

Yeah, our local Home Depot and Menards no longer sell those bulk bags. I used to buy a couple big bags every year, but none to be had this year. Menards has some bags for clearance at non local stores (400 miles away), but they want more to ship the bags than the bags cost themselves.

 

[NatJ]

Good soil takes years to get just right.

That is the point of "Mel's Mix"--it is meant to be right from the very beginning, for impatient people, no matter what kind of soil is already in their area. I haven't used it myself, but I can see why some people would want to.

However, nobody around here sells the big 3 cubic foot bags of vermiculite anymore. The big box stores used to carry the stuff and it was not too expensive, about $18 per 3 cubic feet. I am not going to buy a small bag of the stuff for $$$ because it would just cost way too much for a raised bed, about $96 for 3 cubic foot equivalent.

Have you looked online?

For example, on Walmart's website I can find a 4 cubic foot bag, delivered for free to my area, for about $40. (Not directly from Walmart, but from a 3rd party seller on their website.)

And I can find bags of perlite, 4 cubic feet, on Amazon for similar prices, also with free delivery. (Vermiculite looks more expensive than perlite on Amazon.)

I am sure that delivery charges would be different in different parts of the country, but it could be worth looking if you haven't yet. I would also check websites for Target, Home Depot, Lowes, and so forth.

I called a local nursery and talked to the owner. He suggested, given the fact that we no longer can get bulk vermiculite or perlite, I should just use 1/2 compost, and 1/2 topsoil, and call it good.

That mix would probably work well. It might behave a little differently than the Mel's Mix, depending on what kind of topsoil is available (sand and clay would be quite different from each other, but each can grow good crops once you learn how to deal with it.)

I'm just a struggling gardener, and I don't know much about anything. Would anyone please advise me on what mix they use for raised beds today given that vermiculite and perlite are no longer available in bulk bags? Thanks is advance for any help.

I did a bit of googling, and I find there is a Square Foot Gardening forum. Someone on there was saying to just use more compost if you cannot find vermiculite or perlite. I found some other site suggesting sand if you can't get vermiculite.

Personally, I've just used local soil with lots of compost.

 

[gtaus]

How tall are the beds? You only need 8-12" of good soil for the beds. You can fill the bottom with organic material that over the next year will break down and become available for subsequent plantings. Cardboard, newspaper, sticks, straw, leaves, unfinished compost, even junky native soil. All free plus you get something out of what one would consider trash. 1/2 compost and 1/2 topsoil is more than good to get up and running.

My new raised beds are 16 inches high.

I was going to make them into sub irrigated planters using 4 inch drain pipe on the bottom, an overfill pipe at 3.5 inches, and then filled up bed with the potting mix of 1/3 compost, 1/3 peat moss, and 1/3 vermiculite. I built some elevated planters for my front and back decks of the same depth and they are great. I get more beans out of my 2X4 foot sub irrigated elevated bed then I get out in my garden with lots more space planted. I believe it is because the sub irrigated planters have a large reservoir of water sitting in the bottom of the planter all the time feeding the roots as required. However, for the system to work, it is supposed to be filled with potting soil for it's wicking effect. I don't know if 1/2 compost and 1/2 top soil would work as well in a sub irrigated raised bed. The guy on YouTube says heavy soil will not wick up and the sub irrigated system will fail.

Moving on to your other comment, my backup plan is more in line with your suggestion. I would make the new raised beds into hügelkultur beds. I have lots of old rotten wood on my property and could 1/2 fill my raised beds with that and top it off with a compost/topsoil mixture. I have tons of chicken run compost (wood chips, leaves, grass clippings) ready to harvest.

Speaking of tons of chicken run compost, can I just fill up the raised bed with the wood on the bottom and just top it off with compost and not even bother with mixing in topsoil? I live on a lake, and our soil is primarily sand. If using 100% compost is not a good idea, I can get a Bobcat bucket full of rich black Red River Valley topsoil at a local nursery for $50.00. If I have to buy topsoil, that is what I think I would do.

 

[gtaus]

1/3 compost, 1/3 top soil and 1/3 mycorrhiza pro mix (plenty of perlite in the pro mix for raised beds)

I'll have to check out the pro mix. Thanks.

 

[gtaus]

That is the point of "Mel's Mix"--it is meant to be right from the very beginning, for impatient people, no matter what kind of soil is already in their area. I haven't used it myself, but I can see why some people would want to.

I think that is right. I believe he stated something like you can grow vegetables now with his mix, or spend a number of years trying to improve poor soil to get the same results. Since I have so much compost, maybe that is no longer a concern and I really don't need Mel's mix anymore.

Personally, I've just used local soil with lots of compost.

I am leaning that way myself. Certainly the least expensive option and I already have everything I need on hand.

 

[gtaus]

For example, on Walmart's website I can find a 4 cubic foot bag, delivered for free to my area, for about $40. (Not directly from Walmart, but from a 3rd party seller on their website.)

And I can find bags of perlite, 4 cubic feet, on Amazon for similar prices, also with free delivery. (Vermiculite looks more expensive than perlite on Amazon.)

Our local WalMart does not carry bulk bags of vermiculite or perlite, but I did not consider checking online. Ditto with looking for that stuff on Amazon. I'll have to look there, too. I still have about 3 weeks to finish off the beds, so if I have to order supplies, I have time. However, given the feedback I have received from many of you, I might just try using more compost and mix in some native topsoil.