AusBonsai

ive got a wisteria and trident and they have a big thick root going straight down about 250mm long, then there are lots of smaller roots coming off that. how much can i cut off the big root at one time so it will fit in a bonsai pot? there only young trees, a few years old.

Hi Milly

If there are other roots at the soil level you should be able to cut the whole large root off both trees at the end of winter when the buds swell but before leaves open. If the thick root is all they have you may have to reduce it over 2 years, but you could still cut and treat them like a larger cutting. Bit hard to tell you 100% without seeing the specimens.

Safest time of year at the end of winter.

Tony

I dug out a few roots to use as root cuttings from my sisters house about 2 months ago, Dunno if they will survive, but I am hoping

Ken

Trident maple roots can be cut VERY hard. With field grown trees I routinely cut all the roots (up to 3 cm diam) back to 2-3 cm long. This causes many new roots to grow from the cut ends giving a much better root system on the tree for future. As long as you leave some root on the tree it should be ok.

The real question, Milly, is whether you should be putting really young seedlings into a bonsai pot???? Think about what you are trying to achieve.
Most experienced growers would put small seedlings into a larger pot, allow them to grow quickly and style them by cutting and growing for a few years to get a substantial trunk. In a bonsai pot it will take many years to achieve the same.

thanks, no worries