Test for the Best Medium for Seed Germination

I did a little comparison of seed germination between three mediums: soil, Rockwool and seed starter plugs. Years ago, I always used Rockwool, I liked the lack of mess, the ease of transplanting, and ease of planting, just put a seed in the hole and you’re done. I do not like that it is not a renewable resource however. There can also be problems with pH depending on what species of plant you are growing. The seed starter plugs that are preformed have all the same benefits minus the pH problem, plus they are renewable. And of course, soil is what plants evolved to germinate in, and it is my medium of choice, with some variations so I gave that a try to.

Soil seems to be the best thing to germinate seeds in. the seeds germinated quicker, and grew as fast as either of the other two mediums. However, it is messy, and I have not tried to pot up   the seedlings yet, so there is the possibility of damaging the seedlings when I try to dig them out. The Rockwool was the worst, to say the least I was disappointed. I don’t know why I liked it so much. For me this just shows you need to try new things to see if you can improve what you are doing. The germination time was about the same for all plants, but the Rockwool seedlings did not grow well compared to those in the starter plugs or soil. I think it was a pH problem as the plants just grew slower and were smaller. I think I am done with Rockwool forever. Don’t get me wrong, I am NOT giving it a thumbs down it has its uses especially in hydroponics, but I am a dirt grower for the most part. The seedlings in the starter plugs grew nearly as well as in soil, and potting up   will be a snap. The only drawback to the plugs is that for plants like basil, lettuce and others with very small seeds, you may be better off with soil since the small seeds can fall down into the hole, or may not grow well if they are placed on the top of the plug. I did grow chives (small seeds) in all three mediums so you can grow plants with small seeds in plugs, but I got 1-2 plants per plug and 3-6 in the soil, so soil is more economical with small seeds. If you have not tried the seed starter plugs, give them a try.

Good Growing
Dr. E.R. Myers


Anonymous said...

Did you pre-soak your rockwool media in PH balanced distilled or de-ionized water?. High Ph retards germination, and some species are sensitive to Alkalinity or Acidity.

Dr. E.R. Myers said...

Thanks for your comment, I soaked the rockwool in a solution that was pH 6.0.