Hello from western NC - question about bottom fill for raised bed

hopekahan 2/17/2023, 10:22 am

Hi! I am planning a vegetable garden for the FIRST time this year and I discovered SFG after I already purchased a 17" raised bed frame and filled the bottom with logs, sticks, and dried leaves (on top of hardware cloth and layers of cardboard). Today, an email came out from SFG with a reminder that it's time to create MM! (thanks for the email!) and I noticed it also says:

"New Gardener Tip: If your garden bed is deep, put clean sand or topsoil on the very bottom (not logs or branches, as you don't want your base to decompose!)."

Can you tell me why it's bad for the base to decompose? I am wondering if I need to unload what I have already put in because it's not good for the garden or if it just means I'll need to top off the MM over time as the bottom layers decompose.

OhioGardener 2/17/2023, 10:36 am

hopekahan wrote:
Can you tell me why it's bad for the base to decompose? I am wondering if I need to unload what I have already put in because it's not good for the garden or if it just means I'll need to top off the MM over time as the bottom layers decompose.

I wouldn't use the word "bad" as much as inconvenient and expensive in the long run. It is not recommended for building a SFG. As the logs, brush, etc., decompose it will be necessary to add more and more MM to the top of the bed to bring it back up to the desired level. This not only is a lot of extra work to replenish the gardens, but adds the expense of buying more compost, vermiculite, and peat.

If you have not already added the MM to the top of the bed, it would be good to remove the logs, brush, etc., and fill with topsoil, sand, etc., and then add the MM to the top of the bed.

**sanderson** 2/17/2023, 9:51 pm

What OG wrote. Fill the bottom with inert material and will not breakdown. Or be prepared to add more and more Mel's Mix.

**Scorpio Rising** 2/20/2023, 1:23 pm

So, I learned this the hard way, hopekahan, I filled my original (legacy boxes: actually old window boxes that were no longer used) SFG with raked out leaves from my front perennial garden. I had to fill these many times, almost annually to keep the level normal. Yes, it probably helped enrich the soil. But Ca-Ching! $$$$

That being said, my boxes were about 1 foot deep, most with the bottom not intact. So somethings did come into contact with the soil if they went deep enough.

They are going away this year (condition too bad) and that area will serve as a pumpkin/squash/corn planting zone. All good in the end with a lot of money in between.

Sponsored content

Hello from western NC - question about bottom fill for raised bed

Hello from western NC - question about bottom fill for raised bed

Hello from western NC - question about bottom fill for raised bed

Re: Hello from western NC - question about bottom fill for raised bed

Re: Hello from western NC - question about bottom fill for raised bed

Re: Hello from western NC - question about bottom fill for raised bed


	Hello Guest! Welcome to the official Square Foot Gardening Forum. There's lots to learn here by reading as a guest. However, if you become a member (it's free, ad free and spam-free) you'll have access to our large vermiculite databases, our seed exchange spreadsheets, Mel's Mix calculator, and many more members' pictures in the Gallery. Enjoy.