What's the best way to grow silver birch tree's to advanced (6'+)stage in pot's to plant out later.?? Any advice would be appreciated. Len. P.S. Is this the best way to grow big/quickly.?
The main thing to watch out for is too much heat, loss of water and nutrients as posts are really a major compromise for any plant, especially a tree.
#1. Don't let the pot get too hot, standing in direct sun a black plastic pot will heat the roots to dangerous levels on a warm day. Shelter them from direct sun or group many pots together and shade the outer ones only.
#2. Keep plants well watered, usually at least once per day.
#3. Fertilise often as nutirents leach out too, though sustained release granules are your best bet or pot them up in the first place with a good potting mix that has fertiliser combined within it.
#4. And then just keep potting up the trees to larger pots every year or so ensuring that the roots are not getting fixed into a spiral pattern. Circling roots tend to become a habit that the plant cannot get out of once planted out into the ground. This means that they cannot create the stability they need, or get the arrany of moisture and nutrients they need to grow properly.