New raised bed.... 60% compost, 40% mushroom soil?

[Gardener123]

I called a place today to get 6 yards of soil for my new raised bed.

The lady asked asked me how deep the bed is. I told her that it was about 28" deep.

She then said "I only need to know the depth so that I can get you the right soil mix, and for a brand new bed, a 60% compost / 40% mushroom soil mix is perfect."

I was about to ask if that was really correct, and she said "Trust me, you will thank me for this."

Does that sound right?

[applestar]

It depends entirely on how much actual soil is SCRAPED UP AND ARE MIXED IN with these materials which are normally considered soil AMENDMENTS.

Hmmm "mushroom soil mix" -- this might not be pure "mushroom compost" which is what I was thinking, so it probably does contain some amount of soil.

[imafan26]

I guess it depends on what your soil is like an what you are growing. I used to like mushroom compost a lot but I added too much over time and had problems with the more acidic plants. It was fine for cabbages which like alkaline conditions. It has a lot of nutrients but it also contains a lot of salts and some plants are very sensitive to that. It can apparently cause problems with some seed germination. Are you going to mix this with or soil or are you using it as a planting mix? If it is a planting mix, it should contain some soil as well. If this is a place that regularly sells planting mixes you should ask them how to use it. If it can be used as a planting mix for the whole bed or if it needs to be mixed in with the soil and how many inches of mix to work into how many inches of soil.

https://extension.oregonstate.edu/garden ... om-compost

[JC's Garden]

That mix just sounds like it would hold too much water. The only thing I've ever used that much compost for was watercress in a bog pot. Like was already said, their definitions and ours might be a lot different. If you can get a sample, put it in a plant container, add a significant amount of water and observe how quickly it drains and how much drains out. Do the same with soil you are familiar with. Compare the results.

[Taiji]

Oops...not happy to find out mushroom compost can cause some seed germination problems. I just used it today as a covering for some arugula, lettuce and radish seeds. I thought they would sprout easily through it, since it's a very fine mix! Guess I shall see what happens!