Someone gave me three ponderosa pines spp. ponderosa. They were collected in Eastern Washington about 30 years ago. The guy who collected them and turned them into bonsai died 10 years ago. His daughter has been keeping them alive by watering them daily. In 10 years they have never been repotted or fertilized. The trees are still in the Eastern Washington area so they experience temperatures between 100+ and -0 degrees.
The trees are in rotting, cedar pots, the bottoms are gone and the roots are coming out. They were kept on a patio in full sun. The trees are 3 to 4 feet tall. The bark is old and flakes of easily. They all appear to have nicely shaped nebari.
I’ve watched the Mirai video on repotting ponderosa pines. I have dozens of questions but I will start with two and welcome other suggestions.
Should I wait until spring or repot now and when I repot should I use a pot that is close to the same shape and size as the current pots?
Here is a picture of one of the trees.