Seed starting medium?

I attempted to start my seeds indoors last year using a heat mat, plastic greenhouse setup, and some store bought seed starting mix. The seeds didnt start, or grew slow and never got beyond an inch tall. I changed soil and tried again, and got the same result. In late spring I just put some seeds right in the ground, and they grew ok. I want to try starting early again this year. What soil would work best?

Could it have been a light issue?  I use a seed starter mix, but that is only because I ran into a good deal last fall.  Any quality soil or soil/compost mix should work.  This year I had to restart cabbage 3x.  The 3rd batch is doing great.

I bought some Big Box Store top soil to do a Bean test on horse poo.  I did horse poo and top soil 50%/50% and some straight top soil.  The beans did not grow on the top soil but did great on the mix.

Last year I made my own starting mix out of the black walnut hulls I composted in the basement over the winter. I have tried to hull the walnuts then dry them but I prefer them composted. I layer them between soil in 5 gallon buckets and the hulls deteriorate pretty quickly and I get to crack and pick thru a dozen or so every other day, but on to the story:

The buckets I had them composted in were previously used as planters and had drainage holes, but the soil the walnuts were in was decidedly wet so I thought that would be a good addition to the soil of my early spring vegetable starts and this proved to be the case, the soil in the little pots remained moist and spongy and absorbed irrigation easily so I planted a few flats worth and set them out in the sun and wa'd'ya know? A squirrel excavated them looking for the nuts!

Burl, did any of them grow?  Black walnuts give off juglone which doesn't play nicely with many garden veggies.

Adam, one year I used seed starting mix for some plants and potting soil for others.  The seed starting mix got the peppers about an inch tall and then they sat there for a month and never grew further.  The potting soil did just fine.  I think the seed starting mix is just to get the started and then they need to be potted up in some soil that has more nutrition in it.

John F Dean wrote:Could it have been a light issue?  I use a seed starter mix, but that is only because I ran into a good deal last fall.  Any quality soil or soil/compost mix should work.  This year I had to restart cabbage 3x.  The 3rd batch is doing great.

It had light from morning until afternoon, should have been fine. Very strange.

Mike Haasl wrote:Adam, one year I used seed starting mix for some plants and potting soil for others.  The seed starting mix got the peppers about an inch tall and then they sat there for a month and never grew further.  The potting soil did just fine.  I think the seed starting mix is just to get the started and then they need to be potted up in some soil that has more nutrition in it.

That's exactly what happened to mine, I'll try real potting soil.

Seed starting mixes are generally “soilless”, with just peat or coco fibre, perlite and something to balance the ph like lime or oyster shell. I usually add 10% worm castings and or well aged (6months after heat dies down) compost. Nothing even remotely “hot”, but the horse poo experiment would seem to contradict that rule for me. In general I’ve moved to starting seeds in the ground in diverse polyculture on hugels because they seem to grow better and I don’t have the time to micromanage plants for all the acreage i am managing. I produced thousands of pounds of food last year off less than a 1/4 acre of hugels using primarily broadcast seeds and seedballs of diverse mixes (50+ species and hundreds of varietals from giveaway year old seeds).

If I have more help, I do often turn them towards seed starting in pots in a hoop house, with watering done from the bottom in tubs or trays, and water used is dechlorinated and usually has willow cuttings soaked in it as well for root growth. This really seems to help avoid problems I now associate with overhead watering: dampening off and fungal problems in general, seeds washing away, compaction of the soil, shallow and weak root systems. I also almost always use 4” pots or larger, because otherwise heat and moisture fluctuates too much and I have to water daily or more. I wonder what your high-low temps have been when you had almost no germination. The seeds might have cooked. Also, when we get what seems like 0% germination, it is often the result of herbivory, where a squirrel/rat/slug/bird just mowed them down right after they sprouted or just dig up the seed. When we start seeds is right around the hunger gap for many animals, who will be desperate for any food source they can find and are thankful for the buffets we line up for them in neat rows.

Mike Haasl wrote:Burl, did any of them grow?

I'm repeating the experiment on the windowsill so I'll keep you updated. I read somewhere that black walnut hulls weren't a problem after being composted