Southern Agrarianism and the culture of the Old South

Starting Seeds

I usually use soil blocks to start my seeds rather than plastic trays (although I use some of those also). Soil blocks have a number of advantages – plus a few disadvantages – over plastic trays:

  • Soil blocks are made using the same soil it will be planted in – nothing to buy and stock up on.
  • They are made using a very sturdy “soil blocker” that, if well cared for, should last decades – if not a lifetime.
  • There is no root disruption when planting, so it can be used with plants that normally do not transplant well.
  • “Air pruning” means that the seedlings do not get root bound (where the roots start to coil around the sides of a plastic container). When the roots reach the edge of the soil block, they simply stop growing; they resume growing outward when the soil block is planted.
  • The disadvantages are that 1) it takes a bit more effort than simply filling up a plastic tray; 2) although they are surprisingly strong, they will not withstand heavy rain or watering or rough handling; and 3) with more exposed area, they can dry out quickly if you aren’t careful.

(Note: Be sure to see the update regarding this.)

After rinsing in water, the soil blocker is pushed down into the soil mixture.

Push it down firmly several times to pack as much soil into the molds as possible.

Push more soil into the molds using your fingers until it will not take any more. It needs to be a solid block of soil.

Scrape the excess soil away from the soil blocker using an old knife blade or something similar.

Position the mold over a tray or whatever you will be putting them in. Don't try to crowd them too closely.

Set the soil blocker on the tray with the blocks lined up straight.

Push down on the spring-loaded rod while pulling up on the handle. The blocks should come out smoothly.

When the blocks have been released from the mold, you might need to use your fingers to push any loose parts of the block. A bit of loose material on the top is not uncommon.

Two metal putty knives work well for picking up and moving the soil blocks.

The soil blocks have a seed hole molded in (you can change the pins for different size seeds). After adding ONE seed per block, add some vermiculite or perlite to cover the seed.

The seed trays are then placed on a seed warming mat to keep the soil warm.

A clear plastic cover is used to keep the soil blocks from drying out from the seed warming mat. It is best to keep the seeds in the dark at this stage, so the clear plastic covers should be covered with a dark material.

Within a couple of days, the sprouts will appear. Remove the clear cover and place the trays under florescent lights designed for plants. Lots of light is very important at this stage, otherwise they will grow spindly and not have the strength to stand erect.


  1. Amy @ Homestead Revival

    Thanks for the link Stephen. Your tips are great and I’m much more encouraged after reading your response and several others. I’ll try to post on how it turns out when I get my amendments in.

  2. John Yelvington

    There is a product that I use that works very well. You may have heard of it. Its called DelAg Seed Coat. Its supposed to give more nutrition to seeds. And, can actually make them more drought tolerant. It pretty much does what it says.

  3. Stephen Clay McGehee

    John – that sure sounds interesting. I did a Google search on “DelAg Seed Coat” and it came up with nothing. Could you check to see if it should be spelled differently? Thanks!

  4. John Yelvington

    I apologize! I’m terrible about typos. It is DeltAg. The website is most people use it for food plots. However you can use it on any type of seed.

  5. Stephen Clay McGehee

    Thanks, John. I’ll definitely be checking it out.

  6. John Yelvington

    I hope it will benefit you. It came to my mind while I was reading about the ECHO farm. I definately believe that they could use this and have good results.

  7. Stephen Clay McGehee

    I know that ECHO tries to just use things that are readily available “on the ground” rather than something that would need to be shipped there. We work very closely with missionaries in Sierra Leone, West Africa, and getting anything over there is a major task. Delays and theft are a routine part of shipping anything over there. We are putting together a 20′ shipping container to be shipped over there (date unknown at this point), so that might be a good opportunity to get some over there. Thanks again!

  8. beaver

    the pics are great..thanks for sharing.

    Just wondering how you water your soil blockers?

  9. Stephen Clay McGehee

    Thank you – glad you like the photos.

    I have two ways that I water the soil blocks:

    • The best way is using a misting nozzle called “Fogg-it” made by the Fogg-it Nozzle Company in Belmont, California. It is rated at 1/2 gpm and is made of solid brass. The main nozzle has three small fog nozzles on it. If you use it with good clean water, it should last a long time.

    • The second way is to put the tray (which has drainage slots in the bottom) inside a solid tray that has about an inch of water in it. This lets the soil blocks gently soak up water from the bottom. I usually just use this method when I have neglected them too long and the blocks have really started to dry out too much.

    I probably water them less than most folks recommend. I have found that I have fewer problems when I keep them just barely moist.

  10. Sarah S.

    A few questions (maybe addressed elsewhere?)

    1) What soil mix do you prefer? Would the “mix” for these be different if I’m going to be planting them in northern soil?

    2) If I don’t have the metal mold form and don’t care about the specific shape, would any metal form work if it is approx. the same size? (Side thought – I’m wondering if a more rounded shape would create a more “open” root structure???)

    3) How warm does the warming tray get? I’m wondering if I could use a heating pad on low under a towel and get the same effect? Also, does it need to stay consistently warm or could it be on for a time and off for a time? (Our heating pad takes a lot of electricity.)

    4) I’m sure I’ll think of more questions the closer it gets to the time to sow…

    (Can you tell I try to NOT buy more “gadgets” if I can make do repurposing thing? 🙂

    “Sow to yourselves in righteousness, reap in mercy; break up your fallow ground: for it is time to seek the LORD, till he come and rain righteousness upon you.” – Hosea 10:12

  11. Stephen Clay McGehee

    Hi Sarah – good to hear from you!

    1) For the soil blocks, I have been using a 50/50 mixture of peat moss and coarse vermiculite (Pearlite should work well also). I also add in just a bit of organic fertilizer in the mixture. If you’re only doing a few of them, it may be cheaper to just buy a bag of good potting soil and use that. I read about folks having some really specific recipes for using soil blocks, but I’ve had good results with just about anything. If you can wet the soil and squeeze it into a blob that will hold its shape, it will probably work just fine. The first time or two, I didn’t add any fertilizer and they kind of “ran out of steam” once they got up a bit. Don’t use too much though – just enough to give them something to feed on after they’ve sprouted.

    2) I have seen plans on the web to make your own using sections of PVC pipe. It should work just fine, but the round shape means you can’t pack as many into the same area and still have the same amount of soil in each block. Not a big deal though. There is nothing special about the soil blocker that I’m using – in the end, it’s just a mold. The important thing is that you need to be able to pack the growing mixture in pretty tightly and have a way for the excess water to be squeezed out when you’re compressing it.

    3) The warming pad is set for about 10 degrees above ambient temperature. I have heard of folks just setting the seed tray on top of the hot water heater. That’s a time-honored way as I understand it. You probably don’t want to use a regular heating pad though – it would get way too hot. You just want it warm enough to make the seeds think that it is Spring time and warm enough to grow once they have sprouted.

    Always good to hear from you. Take care and God Bless.

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