35 block soil blocker

Soil Block Mixes

We are giving a co-presentation at the Pacific Northwest Cut Flowers Growers Conference held as part of the Oregon state University Small Farms Conference this weekend on Feb 19th. as part of this presentation we wanted to make publicly available our soil blocking mix recipes and the suppliers that we have found to be key in successfully getting flowers germinating and growing well on  soil blocks.

Bare Mountain Farm: Soil Block Mix Recipes ( current as of 2/15/17)

¾" mini blocks  (Using 3 gal or .6 cu ft buckets = 1 part)

(Makes ~ 3.6 cu ft of mix)

All peat compost and soil are sifted to remove oversize

4 part peat moss

1 part compost

1 part plug grade perlite

Lime:

Mix 1 1/3  cup dolomite lime #65  into peat first

Base fertilizer:

1 cup calphos (powder not granular)

1 cup oyster shell ground

1 cup Activated Biochar(basalt rock powder worm castings ~ 1% by of total peat & Compost by volume)

1/4 cup humic or humates granular or ground (optional)

Std 2" and 1.5"  & 1.125” blocks (Using 3 gal or .6 cu ft buckets = 1 part)   

(Makes ~ 4.8 cu ft of mix)

All peat compost and soil are sifted to remove oversize

3 parts peat

2 parts propagation grade perlite

3 parts compost

Lime:

Mix 1 cup dolomite lime #65 into peat first

Base fertilizer:

1 cup. Feather meal or cottonseed meal or blood meal

1 cup. calphos (powder not granular)

3 1/3 cups Activated Biochar(basalt rock powder worm castings ~ 3% by of total peat & Compost by volume)

1 cup oyster shell ground

1/4 cup humic or humates  granular or ground (optional)

Std & Mini mixing formulas:

  • In sifted peat add lime first and mix thoroughly .
  • Mix in 1 or 2 parts perlite and mix thoroughly.
  • Add Base Fertilizer  evenly on top of mixture and mix thoroughly.
  • Add 1st part of compost and mix thoroughly. (Mini is finished after this step)
  • Add 2nd part of compost and mix thoroughly.
  • Add 3rd part of compost and mix thoroughly.

The mix can be stored dry in a tote or area protected from moisture for several weeks.  Its important to note that the mixes used on mini blocks and those other blocks used for seed sowing should not contain any meal products. The biologic processes used to convert these meals to plant available nitrogen has been suspected of hampering flower seed germination but not on a consistent basis. To err on the side of being safe we omit these from any block mix used for germinating flower seeds.

For our compost we use organic compost that is vegan based , no manures used in its processes.  There is some concern about the sustainability of Sphagnum Peat Moss. There is a belief among many that this resource is being depleted. We use Canadian Sphagnum Peat Moss harvested in sustainably managed way. Check this article out from the Ecologist describing what is going on in this part of Canadian agriculture.  Sunshine or Pro-mix have been the peat brands we have used.

Perlite in various grades can be purchased from Growers Nursery Supply in Salem, Down to Earth in Eugene, Concentrates Inc in Portland , McConkey Wholesale Growers Supply in Sumner Wa.

Important points on Biochar

Biochar in its raw form will initial lock up minerals in state not usable by plants.  It needs to go through a period of activation usually minimum of 2  preferably 4 weeks of composting using the following instructions:

If you start with  1 cu ft of bag Biochar = 4 parts

add:  Gia green Basalt rock powder or Azomite 1 part = .25 Cu ft

Organic Worm castings                           1 part  = .25 Cu ft

Bread Flour( Yep! wheat flour)                3  lbs

The bread flour provides a protein & carb food source for the fungi & bacteria in the worm castings

Blend well and moisten this mixture until it feels damp. you'll notice a strong charcoal smell at this point that's normal.  Store this mixture in a dark cool place with good ventilation for a minimum of 2  preferably 4 weeks. After this period of activation you'll notice the fragrance now smells earthy like compost and the texture will be crumbly . If it doesn't let it go for another week.  Once the smell and texture seem right its good to use and don't worry about using it all at once, the longer it ages it just gets better!

In the Pacific Northwest we have several sources for the minerals & meal products used in our mixes, they are:

Concentrates ,Inc.

5505 S.E. International Way
Milwaukie,OR 97222
Phone: 503.234.7501

Concentrates carries: Pacific Biochar, Gia Green Basalt Rock Powder  or Azomite,  Calphos,  Marion Ag:  Blood Meal, Feather Meal, Cottonseed Meal, Oyster Shell Powder,  Humates(Liginite)

Black Lake Organic Garden Store
4711 Black Lake Blvd. S. W.
Olympia, Washington 98512
Phone 360-786-0537

Black Lake carries: Volcanic Rock Powder or Azomite,  Calphos,    Blood Meal, Feather Meal, Cottonseed Meal, Oyster Shell Flour,  Humates(Liginite)

We haven't found Biochar on their website but would inquire Folks, might be able to get it  for you as Pacific Biochar is a Washington state based company.

Down to Earth
532 Olive Street
Eugene OR 97401
Phone:(541) 342-6820

Down To Earth carries: Azomite,  Calphos,    Blood Meal, Feather Meal, Cottonseed Meal, Oyster Shell Flour,  Humates(Liginite)

We know we have seen Bio char in their flagship Eugene store however, its not listed on their website. That being said I'd call to verify. The Folks at DTE are great and really are quite helpful.

McConkey Wholesale Growers Supply

1615 Puyallup St.
P.O Box 1690
Sumner, Washington
98390-0369

(253) 863-8111

We hope this information is helpful.  We will be posting our slide presentation on YouTube in the next week.

Thank you in advance  for viewing our videos. If you like what we are offering, become a subscriber to our Bare Mtn YouTube Channel.  If you would like to make a donation to support our efforts of sharing, that would be greatly appreciated. Just click the card with our logo in the lower right corner at the end of any video or go to our support page here on our website.

Until next time....

Real flowers, Local & Sustainably Grown!