Don’s Expert Answers: Tree approx.2mtr height ( healthy) BUT plastic 400mm pot broken – thinking to repot in Square 400mm – should I add sand or what to it?

Question From:
Ela & Ian in RYDE, RYDE New South Wales

Nature of problem:
Tree approx.2mtr height ( healthy) BUT plastic 400mm pot broken – thinking to repot in Square 400mm – should I add sand or what to it?

Type of Plant (if known):
Cupressus glabra

Symptoms of Plant Illness (please try NOT to diagnose your problems yourself):
Fallen out of broken ancient fragile, plastic pot – not broken by plant’s growth.

Soil Type (e.g. sandy, clay or loam) OR Potting Mix Type:
potting mix ( red aussie standard )

How often do you water the plant:
Water can – daily

How many hours of sunlight does the plant get each day:
6-8 slightly dappled

How long since you planted it:
2years

Have you fertilised? If so, with what and when:
seasol & thrive every 6 months

Is the plant indoors or outdoors:
outside

Is the plant in a pot or in the ground:
Pot

What other treatments have you given the plant:
Worm wee

Upload photo if available:

Other Comments:
Mainly concerned with giving the right addition of plant medium now that I urgently need to repot.
Obviously need to keep rootball together.
Should I add some sand to help drainage
Looking at square pot – 400 W SQUARE X 400 D Approx same dimension as the cheapo plastic pot it has been in that has fallen apart with age & fragility from sunlight – old pot 15 – 20 years old.
Or should I look at a BIGGER pot since I have to repot?
Tree is healthy and starting to bloom with yellow male ” flowers? ”
Thank you for your help.
Best regards,
Ela & Ian

Answer:
If the pot is 400mm X 400mm, then go up to a 600mm X 600mm pot. Please always add the measurement units – here it is mm. Use a premium grade potting mix and no sand. Potting mixes drain well all by themselves. Don