Gardening can be time-consuming and expensive! However, having a good seedling table will help you start your garden off right and get a jump on the season.
You can build a seedling table over top of your grow boxes in your greenhouse to make even better use of the Mittleider Gardening system. First, you attach the frame to the existing grow boxes, then create a removable tabletop that you can use as a seedling table. The seedling table allows you to use heat mats and grow lights if you desire. The tabletops are removable when the seedlings are ready to be planted into the grow boxes below.
In this article, we’ll talk about how to make a LDS Prepper style garden bed seedling table over top of your greenhouse Mittleider grow beds. We’ll go over the steps and the lumber that I used. You can see each step in action in the accompanying videos to make it even easier. But, first, let’s quickly talk about what a Mittleider Garden is and why you need a seedling table.
The Mittleider Garden Explained
The late Dr. Jacob Mittleider, the Garden Doctor, developed a garden system built on the best characteristics of raised bed gardening and hydroponic gardening. This system is designed to grow a lot of highly nutritious vegetables in a small space.
First, you use a system of raised beds or boxes filled with a soil mix that is usually comprised of ¾ sawdust and ¼ sand. This type of substrate helps water and nutrients easily get to the plants’ roots.
A pre-planting mixture of nutrients is added to the soil before planting your seeds in it. Plants are spaced close together, and a trellis is used to grow vertically. That way, you can grow more plants in a small space. A special nutrient mix is added once a week, and a watering system is put in place to slowly but continuously deliver water to the plants.
This system saves water, work, and time. It also cuts down on plant diseases and weeds while increasing the amount of produce you’ll get from your plants.
After the initial setup, this is a low labor system that yields lots of highly nutritious vegetables in a small space. The system works with any kind of natural soil and any climate.
You can use this system in a greenhouse to really extend the growing season. Once you build your grow boxes in the greenhouse, then you can build a seedling table to go with it.
Why You Need a Seedling Table in Your Greenhouse
You can easily build a seedling table over top of your raised beds. You can start your seedlings on these tabletops early in the season, raising them up off the floor (where they are easier to care for) and away from the cold ground. You can also use heat mats and grow lights on the table to give your seedlings an even earlier start.
Once the seedlings are established, then you can plant them underneath the table in your grow beds and sell any extras if you wish. Then you can remove the tabletops to allow the plants below to get the optimum sunlight for growth.
These tables are designed to maximize the space in your greenhouse by using the frame of the grow beds as a base. Use the tabletops when you’re starting seedlings and remove them when the seedlings are ready to plant. Then, you can stow away the seedling tabletops until the next time you need them.
Building My Mittleider Greenhouse Seedling Table
I used LDS Preppers design for my seedling table, making some minor adjustments so that it would fit the size and shape of my existing geothermal greenhouse. LDS Prepper used plastic pallets for the tops of his seedling tables, and they served his purpose well. But they just wouldn’t fit my setup, so I custom-built wooden tops for mine to accommodate the size of the bed and greenhouse that I had already built.
You can see LDS Preppers Greenhouse Seedling Table in his video here. He also talks about his tomato plant sale.
Just like I did, you may need to adjust the size or shape of your seedling tables to fit the size and shape of your grow beds. Or, if your grow beds aren’t built yet, you can make them any size and shape you wish, although you probably want them to be long and skinny so that you can easily reach all of the plants.
Building The Frame for the Seedling Table In My Geothermal Greenhouse
When I started building my seedling table, the first thing I did was build the frame that attached to the grow bed that I already had in place. I used some leftover lumber to keep the cost down, but you can use scrap wood or purchase new lumber. If you don’t have a saw, you can usually have your local hardware store cut it to size for you.
Lumber for the Seedling Table Frame
This is the lumber that I used to create the frame for my seedling table.
- 2 10 foot 2x4s
- 6 36 inch 2x4s
- 3 18 inch 2x4s
I used the 36 inch pieces of lumber to make the 6 posts. I attached a post at each of the 4 corners and one in the middle on each side of the grow bed. You want to make sure all of the board heights are level so that your tables will end up level. If you set a board across the posts, you can put a level on it to see if they are actually level. Also, use a piece of string strung across each side of the bed to make sure the middle post is the same height as the others.
Once the posts are in place, you can put in the cross braces. Mine are 18 inches long because they match the width of the grow bed. I used the 10 foot long 2x4s to finish out the frame on each side.
The final frame ended up being 24 inches wide by ten feet long because that’s what worked with my grow bed. Yours might be slightly different.
You can see the details on how I built the posts and the braces here in my video. The video will give you a good idea of how you can get started on building your own seedling table.
Building the Tops for the Seedling Table In My Geothermal Greenhouse
Now that the frame is completed, I’m going to build the removable tops for the seedling table. These tops won’t be attached so that I can remove them when I want to plant in the grow bed underneath the tabletop.
Lumber for my Seedling TableTop
For the tabletops, I used the following lumber. If you would rather use a pallet, like LDS Prepper, that’s fine, too. But I needed to custom make mine to fit the size of my grow bed and table frame.
- 6 2x2s at 21 inches long
- 6 2x2s cut at 40 inches long
- 21 cedar fence boards cut to 24 inches long
I put the 2x2s together into rectangles, then put the cedar fence boards on top. These look like small, rectangular pallets that fit the top of my table frame.
If I needed to, I could put a few screws into the tops to stabilize them, but so far, they are stable enough that I won’t.
You can check out my video to see how I put each section together and placed them on top of the frame.
With the tops in place, my seedling tables are ready for planting!
Final Thoughts on Building a Seedling Table
Building the seedling table took a little bit of planning and a little bit of lumber, but it will be worth it in the long run. I’ll have easier access to my seeds, and I can plant them in the garden bed below when they are big enough. Also, since the seeds are being started in the greenhouse, they won’t have to acclimate after being started indoors, too. Starting seeds right in the greenhouse saves a little bit more work! Once the seedlings are planted below, I’ll just remove the tabletops and store them until next year.
Is a seedling table necessary to use the Mittleider gardening method?
No, it isn’t necessary, but it does help you to have better control of the conditions for your seeds. For example, you can use a heat mat or a grow light on top of your tables, or you can just plant your seeds in small containers.
Is your greenhouse heated?
Yes, I have a geothermal greenhouse that uses warmed air from underground to heat the greenhouse enough to keep it above freezing. However, you don’t need a heated greenhouse to use the Mittleider Gardening method or seedling tables.