soil block mixes, seed treatment and sowing

july 31 2013

update on my soil mix experiment: I don't like it as my plants don't seem to like it. they germinate ok but then stay tiny and don't show much growth. some of them had good root growth but not much leafy growth.

the photo below shows yarrow seedlings sown at the same time, same soil mix for germination. when I bumped them up to 2 blocks I expected them to jump but they just sat there and did nothing.

so I did a simple experiment and used my soil mix recipe with coir, soil conditioner and compost and then mixed up some commercial organic potting soil and compost. both soil mixes had fertilizer (azomite, greensand and calphos) added. I potted them up the same day and all conditions are the same: light, water, air.

the yarrow plants on the right are in the coir mix. the yarrow plants on the left are in the potting soil compost mix. huge difference. now I have to repot all the other plants I put into my soil mix and hope they rejuvenate themselves.

I plan on sending in the coir and soil conditioner to be tested before I use it again in a mix. I could send in a sample of my mix but I won't be able to tell which ingredient is causing problems. if I send all the components in separately, I will be able to tell the effects of each one.

the compost I used came with a complete nutrient analysis so I will not need to send that in. I may also be able to find the nutrient analysis from the companies that made the coir and soil conditioner.

I found this analysis of coir for agrococo. it looks great and in fact I think I saw this article before I decided to use coir. I may have to leave out the fertilizer since it is higher in macro and micro nutrients.


february 20 2013

some seeds need pre-treatment before planting. stratification and scarification are 2 terms you may come across when researching seed starting methods.  

cold-moist stratification. some of the seeds I purchased (echinacea, ascelpias, vervain, comfrey) needed a cold-moist stratification. I took unbleached coffee filters and let them soak in warm water for 10 minutes or so. then I squeezed the excess water out, split it in half and placed the seeds on the filter. then I rolled it up and put it into a ziplock bag and placed the bag in a jar and put the jar into the fridge. I made sure to put plant info, length of time for stratification and date with each seed bag. I checked the seed after 1 week and all were fine. 2 weeks later I sowed the seeds that needed a 2-week period. the rest are still in the fridge for 2 or more weeks.

butterfly weed seeds on a moistened paper towl

warm-moist stratification. other seeds (calamus and black cohosh) needed a warm-moist period. I used the coffee filter method for them as well, but a day or so later I thought that they might get moldy. so I took them off of the coffee filters and put them into a commercial seed starting soil. I think that vermiculite would work as well. I checked them after 1 and 2 weeks and they are fine.

rolled up and put into a ziplock bag (re-used)

and then placed in a sealed jar and put in to the fridge

february 13 2013

first batch of seeds will be sown tomorrow, valentine's day. I will infuse them with lots of love to grow strong and healthy.

I mixed up the soil and made all the soil blocks a day ahead. I borrowed the soil blockers from the student farm so saved some money. Johnny's Selected Seeds sells them. Johnny's also sells cowpots - containers made from cow manure! yes. great idea.

I took the recipe from Eliot Coleman's New Organic Grower book and modified it a bit. I don't want to use peat moss as that is mined from peat bogs and it takes hundreds to thousands of years to form and even though some say that it's sustainable since it regrows, not in our lifetime it won't. and I am a huge fan of any sort of bog, swamp or wetland and it makes me really sad to see them destroyed. read more about it here.

so I am substituting coir for the peat moss. coir (pronounced like koy ir), is derived from coconut husks. not long ago it was considered waste, but smart creatures we are, and somebody figured out it made a good growing medium. 'course coconuts grow in tropical climates (though I do find some on the NC coast now and then), sooo getting it to the usa does involve large vessels and fuels. and lots of water is used to process it.

so, which is a better, or a more sustainable product? I'm choosing to use coir. some coir is produced in mexico, at least that is the same continent. ideally, I'd like to figure out what materials I can gather myself and use that. vermicompost for one, maybe ground up leaves for another component...anyways, back to the present.

here is my recipe for a mini-block soil mix: 

3.5 gallons coir
1.5 gallon fine compost (vermicompost or mushroom compost work well)
28 ounces vermiculite
1/2 cup greensand
1/2 cup calphos (colloidal phosphate)

I added the vermiculite for aeration and to help retain moisture. I used less greensand and calphos since coir has a higher pH and has more nutrients than peat moss.

this is an experimental soil mix. I wish I had time to send it off to ncda soil labs to analyze it. let's hope my seeds germinate and grow up big and strong.

here is Eliot Coleman's original mini-block recipe:

4 gallons peat
1 gallon compost
1 cup greensand
1 cup calphos

For the larger soil blocks, I am using soil conditioner and coir. soil conditioner is often pine bark fines, by-product waste from pulp industry. the brand I bought, enrich, was a little too chunky to use for the mini-blocks.

the recipe for the larger soil blocks will look something like this: (july 2013 update - plants did not do well in this mix)

4 gallons soil conditioner
2 gallons coir
2 gallons compost (or 1.5 gallons compost and 0.5 gallons vermiculite)
1 cup greensand
1 cup calphos
1 cup bloodmeal

first experiment with soil mix. this recipe was pretty good but I used soil conditioner and it had some chunks in it that didn't fit into the blocker. this mix would be fine for the larger blocks so I dumped all the little blocks back into the wheelbarow and will reuse the soil.

I enjoyed making the blocks. its pretty easy. you need to really pack the soil in the blocker.

I want to avoid plastic as much as possible in the herb production. I followed the practices of organic farmer Eliot Coleman (his books are great resources), and built wooden trays out of scrap lumber to seed my herbs. The seeds will be sown into mini-blocks of soil. No plastic trays no plastic containers. The mini-blocks can be set into larger blocks.

this is the mini-block tray with plant labels and tongs made from wood scraps. the mini-block tray inside dimensions need to be 18 3/4" x 4" x 3/4" and will hold 120 blocks. 

--------------------------------------------------------------------------------------------------------------------------------

2 weeks ago I gathered some finished compost from my bins to add to the soil mix.

I also made some regular sized trays that will hold the 2" soil blocks. regular trays measure inside dimension  18 3/4" x 8" x 2" and will hold 36 blocks.

undersides of the soil blocks with dimples which leave indents on the surface of the blocks and where the seeds sit.

------------------------------------------------------------------------------------------------------------------------------

feb 23 2013

the shed is too darn cold for germination and so I made the decision today to move the trays into the house where they will be warmer. the shed is large and poorly insulated and trying to heat the space would use and waste a lot of energy.

I thought of putting them in the house before I set everything up in the shed but I've had problems with starting seedlings in the house - not enough light or space, trying to keep cats and mice from getting into the trays.

I have a spare bathroom I don't use, no natural light, little space, but it is warm and I do have grow lights. this whole project is an experiment and now I know that the shed is not suitable for late winter/early spring seeding. I'll need to lower the lights a few inches above the trays to prevent long-legged seedlings.

ideally I'd like to have a solar greenhouse. I just need to get the materials together to build one. the saw mill down the road (or over the big hill, as my neighbors say), has lots of free scrap lumber I can go and scavenge. if it ever stops raining, I will take the truck down there and get some cedar. there's tons of free materials out there, you just gotta go ask. I find nice 5 gallon food-grade buckets and jugs for free in the trash area behind restaurants. you may want to ask if you can take them first.

I don't have the advantage of putting a lean-to style greenhouse against my house as the south-facing side of my house doesn't get enough daylight hours. the idea with these greenhouses is that the sun will heat the south wall of the house, and since the house is heated, provide lots of warmth day and night.


2/ 20/2013
so far, no germination but I was out of town for 4 days and not able to provide any heat to the shed while I was away and the temps were getting low at night. I was concerned about leaving a space heater on without any supervision. the low temp last night in the shed was 37F, outside low temp was 28F. I've been recording the temps for a few weeks now and basically the germination chamber is 10 degrees higher than the outside temp.

it needs to stay warmer in the shed to get any germination. I put a crock pot filled with water on low and placed it on the bottom shelf this morning. 

I checked it tonight, the outside temp is 35F and the germination temp is a cozy 55F. that's a whole 20 degrees warmer! way better than a space heater that uses more energy. I don't have a soil thermometer but I'm guessing that the soil blocks are within a few degrees of the air temp.

much warmer tonight with the crock-pot "heater" top number is humidity, lower number is temp.