Tuesday, April 2, 2013

The great seedling experiment

Out of all the gardening tasks I have found raising seedlings one of the most challenging. Like many things it sounds so simple, place a seed in a pot of soil, and add water. Sadly our results can be quite hit or miss. And when you are relying a constant supply of seedlings to keep the garden productive and the family fed, this can be very frustrating. So I thought it time I conduct a series of experiments to learn first hand the artful ways of raising seedlings. My goal is to find a method that is reliable, simple, cheap and efficient.

I decided to make this experiment quite grandiose, and includes:

3 Different sowing methods:
  1. The standard - bury seed in a pot of soil.
  2. First raise a group of seeds together then transplant to pot.
  3. Place seed on soil surface, then cover with a seed raising layer.
10 Different soil mixes:
  1. 1:1 Sand & Commercial Compost
  2. 1:1 Sand & Homemade Compost
  3. 1:1:1 Sand, Compost, Coco Peat
  4. 1:1:1 Sand, Compost, Cow Poo
  5. 1:2 Sand & Compost
  6. Commercial Potting Mix
  7. 1:1 Compost & Coco Peat
  8. 1:1:1 Sand, Compost, Horse Poo
  9. 2:1 Commercial Potting Mix & Compost
  10. 1:1 Sand & Fresh Commercial Compost
3 Different seed raising mixes:
  1. 1:1 Sand & Cow Poo
  2. 1:1 Sand & Coco Peat
  3. 1:1 Sand & Horse Poo
2 Different watering methods:
  1. By hand with spray bottle / watering can
  2. Wicking mat
2 Different sizes of pots:
  1. Large
  2. Small
4 Plant varieties in each test set:
  1. Broccoli - Green Sprouting Calabrese
  2. Lettuce - Winter Density
  3. Beetroot - Early Wonder
  4. Spinach - Baby Leaf
Oh, and I am also testing the effect of sunflower mulch on seeds and seedlings.

All seeds were sown on Friday the 29 of March 2013, with the great seedling experiment off and running. Today I was excited to see a glimpse of life, but I won't tell you what it was. First I would like to know which seedlings you think are going to be the winners of this experiment? Come on don’t be shy, place your bets. I will even think about throwing in some sort of giveaway at the end.

Stay tuned for regular updates.


  1. Hi Jason
    I would like it to be the seed into the soil with a seed raising layer on top.

    I am glad you are trying this.


    1. My bets are on that one too. Do you think pot size, or watering method is going to have an impact?

  2. Ok my vote is for sand and home made compost. No reasoning behind my vote just a guess. I have been so neglectful with my seeds this season I had to go and buy seedlings. Although I have planted broccoli seeds (and bigger seeds like peas as usual) straight into a prepared bed. I hope they come up. I will watch your results with interest.

    1. Growing from seed has many advantages, but it's the end product that really counts. I have learnt to swallow my pride when it comes to buying seedlings. Here is a post about it.

  3. I seem to have more success with seeds sown directly, but maybe because I neglect the seedlings follow-up care in the trays quite often. They seem to need a lot more attention than those sown directly in the ground.

    1. Yes in pots they are very vulnerable to neglect. I sow large seeds direct in the garden but the small seeds don't do so well with the heavy mulch layer that is maintained on our beds.

  4. Jason, we really find timing seedlings to be tricky - they always seem to take so much longer than we planned and then we end up buying seedlings to supplement! We finally bought a heated mat to grow winter seedlings in - it works well, but it's quite small. I'm looking forward to hearing your results!

  5. I think this will depend on when you consider the experiment finished. Are you just testing till the seed put on their first true leaves or are you planning to grow them on to seedlings? Seeds don't require any nutrients to germinate just constant moisture so if we are testing germination to first leaves then my money is on any of the sand mixes in a large pot with wicking mat. When it comes to getting from first true leaf to seedling ready for planting out I would say the sand compost cow poo mix in a large pot with wicking mat.

    1. Great question! The answer is I am testing both. My son thinks I should test all the way to the dinner table.


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