In containers then? For that, a wide array of potting media would work. If in-ground, any mineral soil will do. That, after all, is what it takes to get tree seeds to germinate out in nature-some clearing event, fire,, manual scarification, or something, which clears away all the duff layer and allows the seed to make contact with mineral soil.

+oM

Near the outdoor water hose.

you will need to cover them.. to keep the critters away from them

consider also .. large pots.... put all the seeds of one type.. in one pot ... then pot up individually when they are ready ...

ken

I hadn't thought of using large pots. That's a good idea. Is there any benefits of doing that rather than using like a large flat? Besides it would obviously take up less space.

Personally, I think a tree should never see a pot. Or, if they must see a pot, then hopefully that pot does not hold a tree.

A bed 1 metre in width and whatever length you like is useful and easy to work. You will need soil that is well drained and quite fine (do not use any kind of fine sand, which is not at all well-draining). And deep enough to allow and encourage good roots. Protection from dogs and cats and whatever else is likely to wander up and over and decide that here is a good place to attend to all manner of things. So maybe something that you can place there when you are not working in the area.

It sounds a fine idea, growing some trees from seed. Good luck.

I use pots, but I use rootpruning pots.

I am switching from sowing in (deep) pots to sowing in small raised beds in the native soil where the trees will eventually be planted. Although I have had reasonable germination in pots, I am interested in experimenting with maintaining a continuum from seed to field...and I also find it far easier to maintain stability in a bed rather than in a pot - water, heat (especially at the roots) is more evenly distributed and the lack of limiting depth levels allows for a variation in the young tree roots, even allowing for deeper taproots and a nice horizontal spread.. I really cannot recommend flats - all my tree seedlings wanted to put out a deeper root than a tray allowed - I use 30cm tall, 5 litre pots and grow several seeds to a pot.

Growing trees from seed is addictive, awe-inspiring, practically free and utterly absorbing.

the difference between a pot and a flat... is water management ...

and lets not forget.. media is the most important variable... not the pot ...

anyway ... a flat can dry out in hours.. at any minute for any reason ... the ONLY place i see flats in production [vs homeowners].... is in controlled greenhouses ... where all variables are CONTROLLED .... most of us cant control the variables to that extent ....

a pot will not vary wildly ... in uncontrolled situations ...

now.. you really havent told us when you are doing this .... or i missed it.. or forgot by this point.. lol ...

i was presuming you would be doing this in winter ... and a pot would be very forgiving .... fill with damp media... sow .. put pot away for winter ... see what pops in spring ...

once they are an inch or two big.. maybe early next fall ....THEN they can be moved into whatever future system of pot you might want ... we arent talking about them being in the rooting pot for years ... you asked.. what to germinate them in ...

ken

True, I stick my pots along the outside of the greenhouse and more or less forget about them till March or so - oh the fun of racing out in the morning to see what's up...and generally something new always is. I don't have a particular medium - I often use what's to hand as long as it is reasonably low fertility and friable. So far, in 20odd years of seed sowing, damping off has never been an issue...and I am a lazy gardener - pots are rarely scrubbed clean. I top the pots with fine chicken grit (flint, not oyster shell) which helps prevent thick moss formation. In my raised beds, I simply bumped up the native soil with sieved leafmould so the level is a couple of inches higher. - I 'edge' the beds with river flint, more to delineate boundaries than keep soil in - my soil is a neglected woodland lot of sandy, shelly, alkaline loam - nice stuff tbh. This is all still quite a steep learning curve though so I have no pretense to any sort of expertise

I appreciate all the input guys. Would someone care to explain to me a little more what the "rootmaker flats" and "root pruning pots" are and why they are used?

There are quite a few different types/brands.

There are plastic flats and pots - such as Rootmaker and Pioneer Pots. These are usually smaller in size, for new seedlings. They have holes or slats in the pots that are shaped to "direct" roots to grow and reach the holes in the container. They are then "air-pruned" - the tips dry out when they reach open air at the end of the hole - and branch internally inside the container. This accomplishes a couple things:

1. It prevents "root circling" and rootboundedness

2. It creates a more "fibrous" rootsystem that is easier to transplant and, presumably, establishes a bit better vs a dug tree (with more root loss) or a tree that has circling roots (especially a taproot) inside the container without having to cut or untangle roots.

They're not foolproof or perfect, but I've had good results with them.

There are also fabric containers (smart pots are best known) and they work in a similar fashion, but instead of actual holes in plastic, it's a cloth container with thousands of minute holes in the fabric that the root tips reach and get pruned on.

Rootmaker Corp also makes a "roottrapper" fabric pot that "traps" the root tip, but accomplishes the same thing.

This isn't the only way to grow a tree, obviously, but for me, it works well. It's rather expensive, so if I were growing any more than a few dozen trees at a time, it would be cost-prohibitive. One advantage of the rootmaker flats and pioneer pots is that they're plastic and can be reused for many years. The fabric pots really have to be cut off the rootball and are difficult to re-use, although some people can "roll down" the fabric pot and re-use it, or staple/sew them back together a couple times.

The degree to which you can regulate moisture will play a role in what type of material you start these plants in. So, if misting can be set up, to keep that perfect, evenly-moist but never too wet circumstance, then one could and should use fast-draining medium. I also think a light mix would make for easy bare-root harvest later. Things like builder's sand, perlite, coir, peat, and all the rest, probably throw in some volcanic pumice or something like that.

If your water schedule and method is more crude, you may have to go to a heavier mix to tide things over when you can't necessarily be there to check. Probably my favorite setup would be a raised bed or propagation bench with mister on a timer, filled with very loose, fast-draining material. Heck, I might rig up some bottom hear while I'm at it. Warm planting medium combined with moderate air temps are one of the tickets to success across a wide range of species.

+oM

If I were to cold stratify some of the seeds myself in a bag in the fridge, what media should I use in the bag? Some mixture of perlite and peat? Or am I misunderstanding and there doesn't need to be anything in the bag besides the seeds?

Sphagnum moss or Peat moss is standard, but moist paper towels work.