After repotting nursery stock into training pots, I put them directly on the ground, as I understand the stability of temps is good for the roots. After 6-8 weeks they are doing fine, and recovered/recovering well.
However, the bottom of the pots are muddy from watering, and stuck to the ground, so there is little if any air circulation underneath them through the drain holes. However, we all know roots need/like oxygen.
So which is better, putting them directly on the ground for stability of temps, or on a flat surface (like a bench or board) so air can circulate through the drainage holes?
Or any other recommendations (e.g. on landscape fabric on the ground, or on a flat surface on the ground)?
I do the same thing and have found the same muddy problem. When I’ve seen any issues, such as a specific tree staying too wet for too long, I’ve kept them on the ground but propped up one end of the pot with a block or something. This seems to be the best of all worlds and has worked well for me. Another added benefit of the ground is protection from wind, if you live in a windy area, as I do.
I put repotted trees back into the cool greenhouse on the benches. This protects from wind, is a little more humid, avoids freezing, and is a bit more stable temperature than outside (it has shade cloth and shade from trees). After 2 to 3 weeks they move into a shaded area on the bench.
I like the idea of putting the trees on the ground on landscape fabric to allow a bit more air circulation into the pot and keep them from getting as muddy. I’ll try that next year for winter storage of those that are on the ground.
Gravel is your best friend here, if your situation allows it.
Peagravel warms in the sun, retains heat
But allows water to flow away from the pots
Most on my trees have sat on gravel for years
I finally got some live edge lumber at a good price and made benches this year.
But honestly if you can afford it a 8-12 inch layer of gravel, it is your best friend here, you can dig a hole in the gravel 1/2 bury the pot and it keeps it from blowing over in the wind.
Awesome for overwintering also if you overwinter outside.