Soil Blockers - Test 1

What are Soil Blockers?  Why would you use them?  How do they work?

Those are all the questions I had when I first heard of them, and being who I am, I wasn't able to leave it at that.  The people who sell them, swear by them.  So I was at least mildly interested.  Soil blocks are supposed to work by allowing the roots of the plants to be "pruned" by the air rather than to fill the entire space available and cause a big block of roots, like what happens when growing transplants in the little black plastic egg carton things :).

Pros:

• Transplanting shock is supposed to be non existant
• You don't have to pay for new transplant containers each year (or sterilize the ones you used this year).
• Very very easy to move a transplant up to the next size (repotting).  Soil blockers are built to just dump one block into the next step larger block (which is what talked me into them).
• Buy the blocker once, and use it for thousands of blocks
• Enjoyable to do with kids

Cons:

• $30 for the 2" model, $30 for the 3/4" model, and $100 for the 4" model. 
• Watering isn't a walk in the park
• kids like soil blocks :), and they're easy to drop on the ground

I read up on them, and decided to buy the 2" model.  It's the most popular because it's small enough to be good as a seed starter, and large enough that with most plants you won't need to repot them to the larger size.  If you get the 3/4" model you'll want the 2" one as well.

Using the Soil Blocker

There are several resources on the internet on how to use the soil blockers, but I figured I'd give my own experience as a new gardener.  I tried several different techniques, and still have 1 left to try.  I made the blocks out of normal potting soil from walmart, I used soil to cover the seed, I used vermiculite to cover some of the seeds, and I used seed starter soil and vermiculite for another set.  So here are my findings :)

• Soil wetness

My first problem was getting the proper amount of water.  Very little was actually needed, and I went way over board :).  I was trying to get a peanut butter consistency, and as such there was water everywhere :).  Fun for the kids, but not the best to make actual soil blocks.  I also found that just using the soil without water didn't work well either.  There is a middle ground, and you simply have to slowly add water to figure out what it is.

Notice the healthy root coming out the side

• What to top the seed with

I've seen 1 video that I still want to try out about using a plastic sack, and checking it regularly until the seed has sprouted.  But I tried a few ways myself.  At first I was just using potting soil for my blocks (not the best answer at all), and I just used a little more soil to plug the seed in.  From my tests this was by far worse than any other method :).  Some of those seeds never made it out.  Instead I used vermiculite to cover the seeds, and then used a tsp of water to wet the seed, and this worked wonders.  The seeds have had a really excellent germination rate (except for the cantelope which never did come up) and they come out very very quickly.  

Notice the vermiculite

• What type of soil to use

You want light fluffy soil.  When I got the seed starter mix from walmart I was surprised at how light it was, the potting soil felt more like normal dirt.  I have lettuce growing in each, and the difference in size is astounding.  For my next set I'm going to try the mix from the websites, but just normal seed starter soil from walmart will work and is much better than potting soil.

Plants growing, week 1

Conclusion

I just got the 3/4" model and will be testing them out as well.  So far I'm impressed by the growth of the plants, and we'll just have to see how they do in the ground.  One thing is sure, it's nice to not have to thin out plants or use multiple seeds per spot.  Instead I can just plant my small transplants into the soil, and keep a few extras in case they don't take.