Growing from seed and soils to use suggestions please

[August44]

Hello to all. I am going to try and grow some plants from seed. I did this with flower seeds last year and did OK except for the damping off that was ugly to say the least. I had to start over again with different soils and using H2O2 mixed with water to help with damping off.
Seeds for this year will be apricots (local), Japanese Larch ( Sheffield's), Crab apple (local), and two needle Colorado Pinyon pines, (Sheffields). Last year I ended up using "Black Gold" seedling mix and it was pretty good compared to what I started with, but still had damping off. I will plant seeds in sterilized 3 1/4" X 3 1/4" X 3 1/2" deep plastic pots and then set these in large containers with small pumice 1/8"-1/4" added at about 5" deep.

I'm wondering which of these seeds need to be scarified? Also is there better seedling soils than Black gold and maybe a good way to sterilize the soils. I have heard the heating the moist soils up in the oven to 145 F and that will kill fungus in soils.

Any help or suggestions would be appreciated. Thanks

 

[August44]

Sorry---Zone 6

 

[Wulfskaar]

I had zero success with that black gold stuff. Far too rich and wet for trees. My best success has been with straight peat or garden soil. You can repot into different soil the same spring but peat is what has worked best for me.

Depending on the species and thickness and hardness of the seed shell, you might want to scratch a bit off so moisture can enter. Apricot seeds might need that.

 

[Orion_metalhead]

50/50 compost perlite is what I use usually. Stratification medium is vermiculite or sand... something generally sterile.

 

[Shibui]

I'm wondering which of these seeds need to be scarified?

None of the seeds you mentioned need to be scarified but I suspect Larch will need stratification. Apples often germinate better with stratification too. Apricot germinates well without stratification. I don't know about Pinyon pine but other pines I've grown germinate well without any cold treatment.

Damping off is usually related to overwatering and/or not enough sun and air circulation. Maybe look at trying to change conditions rather than changing the soil?
I sanitise soil in an old electric fry pan or in container in the microwave. Need to be quite damp to allow the steam to circulate through the soil mix. Just be aware that some soil components can burn in the microwave. Not sure if it was charcoal or some of the sand particles that reacted or if that batch was just a bit dry but it melted holes in a plastic icecream bucket and filled the microwave with smoke.

 

[Coppersdad]

I have three small fans running constantly in my 9x14 greenhouse. My seed trays are heated only by mats under the trays.
I do keep a temperature average of about 60 in the greenhouse for the tropical trees that are on different benches.
Have never had damping off with pines, larches or maples in the past eight years. I do plant in individual cells with a new seed planting mix with 25% fine pumice. (Of course, by posting this I'm likely tempting fate. aren't I?)

 

[August44]

I have three small fans running constantly in my 9x14 greenhouse. My seed trays are heated only by mats under the trays.
I do keep a temperature average of about 60 in the greenhouse for the tropical trees that are on different benches.
Have never had damping off with pines, larches or maples in the past eight years. I do plant in individual cells with a new seed planting mix with 25% fine pumice. (Of course, by posting this I'm likely tempting fate. aren't I?)

Could I ask what you new seed planting mix is Pls? Help appreciated.

 

[Coppersdad]

Could I ask what you new seed planting mix is Pls? Help appreciated.

I often buy what leans toward cheap from a local big box store. As long as it's not the cheapest or a name I don't recognize, I use maybe a middle priced brand. We try to stay away from anything that has even a hint of fertilizer in the potting soil. We only reclaim or reuse soil for repotting and never for seed starting. You can probably tell I'm a fan of lighter consistency soils for seed starting and early seed development. Thus, the addition of 25% fine pumice. There are sure other additives that lighten up a soil, I just don't choose any of the ones that either float or might encourage a lot of water retention as I'd rather be in control of the water.

We also scrub our trays, cells and seedling pots with Dawn dishwashing detergent and rinse then allow to dry in direct sunlight. It may be a bit of overkill but it's what we were taught as Master Gardeners and it seems to work. (I just realized I used "we". I share this greenhouse with my bride of almost 60 years. The reason??? Half a greenhouse is much better than no greenhouse at all!)