Deconstructing paradigms: Do veg's need special "seed-starting" soil? Part 3
More success, and a few setbacks using home-grown cold-processed compost.
Cliff notes:
I’m feeling a lot more confident using cold-processed compost for starting vegetable seedlings. But I did have a couple of setbacks to report.
Trials that have gone well so far: tomatoes (mostly), parsley, lettuce, peas, kale, runner beans, fava beans.
I need more info on Song Cauliflower, Sungold Tomato, and a pest on my garbanzo beans was my biggest setback (but only on some seeds).
This is part 3 of my quest to find an alternative to plastic-bagged peat-moss and coconut coir. Part two shows a research into what other gardeners in our region are using - a few are doing cold compost like myself with great success. I also detail my complete failure with a commercially prepared seed-starting mix that uses neither coco coir or peat.
I’ve done a whole bunch of experimenting in the last few weeks. My trials have been using several six-packs that my husband 3-D printed. One side of them (3 cells) are filled with Black Gold seed-starting mix. The other side is filled with cold-processed compost. For the most part, everything has gone surprisingly well.
Tomato trials:
This photo is two of my tomato-seed starting trails - one side is Baylor Paste, the other side is Cosmonaut Volkov. You can see the 2 rows of Black Gold seedling mix in the middle, the compost—started ones on the outside. They came up uniformly, except the one cell that didn’t germinate which is totally normal to have some not germinate.
I also did tomato trials with Sungold and Azoychka. The Azoychka came up evenly on both sides as well.
The Sungold, however, did show a difference between the two sides. I’m sorry to say I neglected to take a photo. The Sungold was stunted on the compost side compared to the bagged potting mix side - they were about half the size before I potted them up. I don’t know if this will make a difference in the long run, as they will both be planted out in the same garden soil and those seedlings are likely to catch up.
Regardless, I’m doing that trial on Sungold again. The first thing I want to determine is if the result is consistent. If it isn’t consistent, then I know it was just something about that bit of compost that the seedlings didn’t like. If it is consistent, I’ll know that there is something the tomato likes better about the bagged compost. In the end, I’m pretty sure the difference is only minimal on them and it probably won’t matter.
Lettuce trial:
These San Juan lettuces show even germination between both compost and bagged potting mix. The first trial I did with lettuce consisted of only lettuce on compost, and I felt that they came up really well. However, this is before I got the idea of starting them side by side with compost and a bagged mix. As you can see here, they don’t seem to care one way or another if their starting medium is commercially prepared seed mix or homemade cold compost.
I feel confident only using compost on lettuce now.
Parsley trial
Likewise, the Gigante D’Italia parsley did just fine with compost on one side and bagged soil mix on the other. I am now confident that parsley does well on cold-processed compost.
Note in this photo you can really see the difference between how much moisture each medium holds. Perhaps those Sungolds like more moisture in their seedling stage?
Runner bean trial
These Moldovanesti Buffalo beans showed fairly even germination - though one seed didn’t come up. I’m now trialing two six packs of compost with these. I’m feeling fairly confident on legume species, although I did have one setback on legume I’ll talk about below. I’m cautiously confident on legume species.
Cauliflower trial
This Song Cauliflower shows a different story though. Yikes, there is a huge difference in the size between the compost-grown and the commercial mix grown. I’ll be doing this trial over again a few times to see if the results are repeatable, and many more experiments on brassicas in general.
Beet trial
Is it just me, or do beets just hate being started indoors? Luckily these Babybeat came up evenly on both compost and on the commercial mix. But they struggle in pots for other reasons. I had some damping off, and then when I backed off the water I have some that succumb to drought. Charles Dowding has great success with starting them indoors, but his cells are much smaller than mine and he plants out pretty quickly. By the time the soil is warm enough for beets to grow well here to outwit slug predation, it’s just as easy to direct-sow. I’m not sure if I’ll keep trying them early.
Garbanzo bean trials
As noted before, my Black Kabouli Garbanzo came up fabulously in pure compost.
But, uh-oh, they didn’t come up when I repeated the experiment. Some weed seeds are germinating though. Easy enough to
pluck out. When I dug up the seeds to find out what was going on, I found a maggot-like creature tunneling through the seed. I’m sorry I neglected to take a photo but maybe you don’t want to see that anyway.
The first thing that occurred to me was perhaps that perhaps the pest that Carol Deppe talks about in one of her books The Resilient Gardener. A pea weevil, that likes to feast on pea seeds, which makes growing dry peas for soup very difficult in our region. I don’t know if that is the pest that was feeding on the seeds - it does seem to be a pest that was only going for the peas - as you can see other weed seeds germinated just fine. If I encounter them again I’ll be sure to take a closer look.
Questions that I want to answer in my next experiments:
-Will freezing compost kill whatever was eating my garbanzo seeds?
-Are my disappointing trials with Sungold tomato and Song Cauliflower repeatable? If they are, what is the mechanism for poor growth?
-Do cucurbrits do well started in compost?
Stay tuned for updates.
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