This is an experiment I did with 2 different seed starter mediums. The top row is plain sphagnum peat moss from a bag; the bottom is a coco-coir based medium with humus, oyster shell, perlite, and azomite, called RG Tupur. I think it's popular with the cash crop growers, and not necessarily as only a seed starter. Anyway, in the end, I had 100% germination from all the Rooster Spur seeds, regardless of the medium, the RG Tupur seeds beginning to hook on day 5, the peat seeds beginning a day later. I could detect no visible difference between the 2 groups.
The reason I did this experiment was because I noticed some of my seedlings were stalled out. Upon root inspection, I could clearly see that they had difficulty rooting through the peat pellets they were in, even though I always break off the bottom third of each pellet when transplanting into a Solo cup. When I transplanted them into a different medium, they took off. I remember having several stunted seedlings last season, but I didn't think to inspect the roots. I believe peat pellets are the culprit, even though I squeeze them quite a bit when soaking them in warm water to ensure complete hydration. And yes, I remove that webbing before transplanting. Anyway, regular loose peat straight from the bag works at least as well, and I doubt the roots would have any difficulty penetrating through since it is loose, and the overall amount of peat in each cell pictured below, is much less than in almost any peat pellet. The RG Tupur, which is very, very light, performed no better. Someone here commented that you could germinate seeds in just about anything, even straight perlite. I think he was correct. As long as the medium is light/loose, it makes little difference what you use. No reason to buy expensive seed starter mixes. Just my opinion.
The reason I did this experiment was because I noticed some of my seedlings were stalled out. Upon root inspection, I could clearly see that they had difficulty rooting through the peat pellets they were in, even though I always break off the bottom third of each pellet when transplanting into a Solo cup. When I transplanted them into a different medium, they took off. I remember having several stunted seedlings last season, but I didn't think to inspect the roots. I believe peat pellets are the culprit, even though I squeeze them quite a bit when soaking them in warm water to ensure complete hydration. And yes, I remove that webbing before transplanting. Anyway, regular loose peat straight from the bag works at least as well, and I doubt the roots would have any difficulty penetrating through since it is loose, and the overall amount of peat in each cell pictured below, is much less than in almost any peat pellet. The RG Tupur, which is very, very light, performed no better. Someone here commented that you could germinate seeds in just about anything, even straight perlite. I think he was correct. As long as the medium is light/loose, it makes little difference what you use. No reason to buy expensive seed starter mixes. Just my opinion.
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