Homemade Potting Soil

I make potting mix every year for my greenhouse seedlings.  I have written about it many times here & here, but every year I refine it, learn more, change things, or get my hands on something new.  This year I learned it is probably best to gather my ingredients in the fall, when it is warm and lovely and my compost is harvestable and not freezing as it is today.

Beacause I wanted potting soil in January and my compost was yes freezing, I bought compost this year.  It is Bio-dynamic compost made with Cow manure from Terra Flora and it looks pretty darn good.  The creator even sent me pictures of it’s microscopic crystals.

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Because I like to deepen my practice of gardening every year I plan to do trials with my seedling mix ingredients and watch and learn, that is once my compost thaws.  I plan to try a mix I got from Santa Fe Greenhouses (during their going out of business sale) a mix with the Terra Flora compost and a mix with my own.  I will of course let you know how it all goes.

So to make your own soil mix for your wooden planting trays (that is what I use and what I think this mix works best for) You must gather you materials–

Compost from your own pile (or another source if not is available)

Soil from your garden

Sand from your arroyo

Peat moss or Coco Peat from your Nursery…(unless of course you have homemade leaf mold composted and ready to go, by all means use that first!!)

I get all this stuff in advance and store it in bins so everything is ready to go when I need to mix.

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Plastic is gross, I know, wooden bins would be ideal, but for now this is what works for me.

Once I have everything gathered I get my wheel burrow, a 5 gallon bucket, my 1/4 shifter screen, a shovel and a hoe.IMG_8859IMG_8870IMG_8860IMG_8863

Here is my the recipe I use, from my Alma Matar, CASFS.

It is a parts recipe, but if you use a 5 gallon bucket as your measuring cup and follow this recipe you will get a full wheel burrow, which will be enough soil for 6 2x1ft seedling trays.

Pour into wheel burrow through a 1/4 screen

1.5 Buckets-Compost

1Bucket- Garden soil

1/2 Bucket-Sand

1 Bucket Peat Moss or Coco Peat

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Anything you shift off can be saved for potting soil for plants that will live only in pots, or can be added back to the garden or compost pile.

Mix everything well with a hoe and sprinkle occasionally with water.

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The moisture level is key, not only does it cut down yucky dust, but you want a nice moist mix in your flat before you seed.

If it is too dry it will actually repel water and you tiny seeds will float away in the run off.

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Give it a squeeze and release

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If it stays in a loose ball and breaks apart when you bounce it in your palm you have got it.  Now store it in a bin with a lid to keep that perfect moisture, or put it directly into you flats and sow away!

And that is that.  Once you have your flats made & potting mix made, now all you have to do is decide what and when to sow…..more on that soon.

Planting into pallets

Is there anything you can’t make out of an old pallet?  Yes, it does take more time and a bit more know-how to upcycle a pallet into a totally different and functional thing, but luckily I have an expert on my side.  Yep, Joel does it again.  This time he made me a new seed planting flat out of recycled pallet wood.

(Note: I do also do make these out new wood too, see here)

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Cool Huh?  Want to try? Here is how he did it.

First, he tore the pallet apart with a flat bar to get the the lumber in order. Image

Then he used the cross pieces which were 3.5inches wide and 1/2 to 3/4 inches thick.  There was mix of oak (harder, longer lasting, heavier) & pine (softer, easier to work with lighter)

 

Then he cut off the split tips with the nails in them- to have clean, split free ends and not to bother with pulling out the nails.Image

Then he cut 2 pieces at 1ft long and 6pieces at 2ft long

He nailed 2 of the 2footers & 2 of 1footers into a rectangular box.  The 2 footer edges over lapped the edges of the 1 footers.  Unfortunately he moved so fast I didn’t get to photograph every step… but I hope you follow.

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Then he nailed the remaining 4 2footers to the bottom of the box using 4d galvanized nails. These are rust resistant and small enough that they will keep the wood from splitting, but large enough to hold your box together when it is full of heavy, wet soil.  Because the wood was irregular enough he just pushed the bottom slats together and nailed…but it is important to note during this step to leave a little space between the slats for water to drain out, but not soil.  I usually stick a quarter between the slats which has always proven to be just right.

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And there you have it.  Here is one I made from Redwood and screws in 2010 (in front) and the new Pallet one (in back).  Image

Similar—-but there are few subtle differences.

*The new one is a bit wider than the other.  As far as size go, I pretty much try to maximize my table space.  If you table is a 3×6 (which many tables are) you can fit 9 2×1 flats on it.  That should be more than enough (much more in fact) for all your seedling needs.  Remembering, when you start seeds in wooden planting flats you will need to divide them or thin them before they reach the garden, so leave space in you table(s) for transplants.  This is basically bio-intensive gardening, but more on that later…here is the next step if you are eager.

*The other difference is that my new flat is mostly oak and the older one is Redwood.  Both have their pros and cons

Oak- Hard, Heavy, Durable,Rot Resistant, Brittle-(Available in Pallets)

Pine- Soft, Not Rot resistant, Light weight, Cheap or free-(Available in Pallets)

Redwood- Light weight, doesn’t spilt easily, VERY Rot Resistant-(Must buy)

Wooden Flats are a great thing to add to your garden shed if you find yourself starting seeds every year.  They are pretty simple to make, relatively cheap and last many years, not to mention they are NOT plastic.  They work beautifully to hold moisture and give ample space for those babies to grow.  Many farms use them, which is where I learned about them.  Here are a few I stumble across while ambling through a sleepy farm in Colorado last spring.

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Yes, I take pictures of other people’s planting flats, I told you I was a farm tourist.

Good Luck and I hope you help rescue one more lonely pallet from the back of your hardware store and put it to good use.

When you are ready here is a link to how to make potting soil for the flats and one on how to plant into them properly.  Let the sowing begin!!