Need Advice on Soil Mix for New Raised Beds

[gtaus]

I struggle with peppers mainly because we just don't get long enough stretches of hotter weather to get them to take off. Depending on how the peppers do this year, I might just call it quits on most varieties (Shishitos do well for me each year so I know I can safely grow those).

My pepper plants have been very discouraging the last 3 years. At some point, I might have to admit it's not just the weather. I don't know. Anyway, just bought 18 pepper plants yesterday to put in the raised beds again this year. Will be getting more pepper plants as I find other varieties at other nurseries.

 

[gtaus]

I still have some perlite and vermiculite left over from when I mixed my own potting soil. I always thought the reason to use them was to "fluff" up the soil for more air/water and so the soil didn't compact.

From what I understand, both perlite and vermiculite are good for aeration of the soil and keeps it "fluffy" instead of compacting. Vermiculite has the added benefit that it will retain water, whereas perlite will not.

 

[BReeder!]

I'm with all the people mentioning compost. My potato beds are raised rows that are half native soil and half unsifted compost. The native soil isn't the greatest, with a fair amount of gravel and clay. However, that compost makes a huge difference and helps keep the soil loose and moist. If I was to fill raised beds, I would mix in some sand too. I don't go crazy with sand in my own garden only because I have a fair amount of clay and sand and clay make for a nasty compound that becomes hard to break up and dig through (like concrete).

 

[gtaus]

I wouldn't do 100% compost, but if you can get that $50 mound of topsoil (nice price!), mix it with however much compost you have to be able to fill up the remainder of the beds on top of the hügelkultur, and I think you should be good to go.

Thanks. I just finished leveling the raised beds, put down the rotten logs in the bottom, topped it off with wood chips to fill the cracks. I now have about 7-8 inches left in the raised bed to fill. As I said, the owner at one of the local nurseries suggested I mix 1/2 compost and 1/2 topsoil for the top layer of the raised beds. He sells the topsoil, and I don't know if that factored into his suggestion or not. But he does have the best black soil for sale as he ships it in from the Red River Valley about 100 miles to the East of where we live.

I don't mind paying $50 for excellent black top soil, and mixing that with my chicken run compost. But can you tell me why you would not recommend using 100% compost? I know some people have suggested just filling up the bed with 100% compost, which I could do because I have more than enough chicken run compost to harvest. I have always mixed soil and compost in the past, but I really don't know why one method would be better than other. I'm still learning and trying to improve. Thanks.

 

[gtaus]

My potato beds are raised rows that are half native soil and half unsifted compost.

I built a cement mixer compost sifter, so I can sift about 6 cubic feet of compost in around 20 minutes. It's just great for that. And I have different sized screens to use, a 1/4" mesh, a 1/2" mesh, and the barrel without any screen uses 1X1/2 inch wire.

Having said that, I am now thinking the only reason to sift compost is if I am using it in a potting soil mix. If I was to start filling my raised bed with compost, would I even have to sift it? Maybe only the sift out the biggest stuff with the 1X1/2 inch screen?

I can tell you that when I used the 1/4 inch screen, the compost was so fine and fluffy that I could hardly believe how good it was. I saved that finely sifted compost for Dear Wife's flower pots, which she really appreciates.

 

[BReeder!]

Having said that, I am now thinking the only reason to sift compost is if I am using it in a potting soil mix. If I was to start filling my raised bed with compost, would I even have to sift it?

This is my opinion and observation exactly. I have a simple screen of hardware cloth and 2x4s. I sift and use it for seed starting and in potting mixes. When it comes to using compost in the garden though, I use it unsifted. I do pull it any large sticks, but everything else just gets put into the garden. Whether it's filling a bed, making a raised row/mound or top dressing I just take compost from my "finish" bin and put it in the garden as needed. It works great.

 

[BReeder!]

Thanks. I just finished leveling the raised beds, put down the rotten logs in the bottom, topped it off with wood chips to fill the cracks. I now have about 7-8 inches left in the raised bed to fill. As I said, the owner at one of the local nurseries suggested I mix 1/2 compost and 1/2 topsoil for the top layer of the raised beds. He sells the topsoil, and I don't know if that factored into his suggestion or not. But he does have the best black soil for sale as he ships it in from the Red River Valley about 100 miles to the East of where we live.

I don't mind paying $50 for excellent black top soil, and mixing that with my chicken run compost. But can you tell me why you would not recommend using 100% compost? I know some people have suggested just filling up the bed with 100% compost, which I could do because I have more than enough chicken run compost to harvest. I have always mixed soil and compost in the past, but I really don't know why one method would be better than other. I'm still learning and trying to improve. Thanks.

100% compost needs to be very aged to prevent nitrogen levels from being too high. If the compost is coarse, it may not have an ideal structure by itself for root support.

 

[jonalisa]

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.

I have all 3 foot raised beds. I fill them with fall leaves, to the top. My soil mix goes on top of this, pushing and weighing down the leaves and ends up filling the top 12" to 18". I use a mix of Happy Frog Garden Soil and finished compost, amended with peat moss. I use leaves, chicken poop and coffee to make my compost so it doesn't need to be sifted. If you are on a budget, buy cheap bag soil and amend with a good compost. Add peat moss for aeration and water retention. I only use vermiculite and perlite in my seed starter.

 

[Percheron chick]

I like to sift the compost to remove the chunks and have a more uniform texture. Improves seed to soil contact. The chunks go in the bottom of the beds

 

[rosemarythyme]

I don't mind paying $50 for excellent black top soil, and mixing that with my chicken run compost. But can you tell me why you would not recommend using 100% compost? I know some people have suggested just filling up the bed with 100% compost, which I could do because I have more than enough chicken run compost to harvest. I have always mixed soil and compost in the past, but I really don't know why one method would be better than other. I'm still learning and trying to improve. Thanks.

Probably depends on your compost, but stability, water retention issues, nutrient balance are all possible problems that crop up if you try to plant in compost only: https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/planting-in-pure-compost.htm

Google "Planting in 100 percent compost" for additional articles