Fixed shallow bed?


#1

I bough an XL last month and am now designing the fixed bed. So far, in every example I’ve seen or read, the wooden raised bed is quite high–12 to 24 inches.

Is there any reason not to use garden soil “in-place” and just build a low/shallow frame? For example, would a depth of 4" or 6" of frame around the garden plot be sufficient? The soil in our garden is already pretty good, and I see no reason to add a great deal of height to the frame unless I’m missing something.

Thanks!


#2

Hey Canada Duane,

Thanks for the post. There’s differing opinions on this but from a Farmbot reliability perspective you will want to build a sturdy frame for the Farmbot. Ideally the frame will not be susceptible to heaving, bowing, cracking or rotting. If the Farmbot X-Axis tracks shift and become uneven it can put unnecessary stress on the motors and the aluminum parts. If the tracks become distorted or misaligned it’s possible that the Farmbot will get stuck and it will have difficulties servicing the whole soil growing area.

There’s a few gardening advantages to having a raised bed.

  1. Soil Compaction - for many vegetables soil that’s too compact can reduce growth. In a raised bed it’s easy to get and maintain soil that is optimally compacted for oxygen levels and microbes. With a traditional garden it’s still possible to get optimal compaction you just need to work at it more to till up the soil and allow more air to get into the lower levels 3 to 6 inches deep. With the raised bed it’s easier because the soil protrudes out of the ground giving more surface area availability to the air.

  2. Water Management / Drainage - Its easier to manage soil moisture levels in a raised bed because the water has some place to travel and drain off. The raised bed also significantly reduces the chance of root rotting.

  3. Soil temperature - It sounds like you may be from the Great White North, so you’re likely to want to get your soil temperature up as much as possible to promote plant growth. You can start your season earlier and increase the soil temperature with a raised bed. It will also extend your season longer into the fall because of the direct sunlight that hits the raised bed and because it protrudes out of the ground which typically stays cooler in the spring as the ground thaws out. (Take off eh!)

  4. Pests - I won’t get into all the different kinds of pests but I will say that some pests can’t climb the sides of the raised bed.

Here’s a few videos that go into a bit more detail on the topic:

Have fun

Marc


#3

Oh wow, thank you for the detailed post! This does help quite a bit when making this decision. So it sounds like there isn’t anything mechanically wrong with building a farmbot that is low to the ground, but there are a lot of benefits to simply raising the garden anyway, and farmbot has built this paradigm into some of its assumptions (such as the instructions on building a raised bed).


#4

Duane,
Yes that’s correct. The instructions for building a fixed raised bed that you mentioned in your previous post are located here:

When you decide and you build it please post photos of your build so that others can see.

Marc