Autumn Repotting Season: The Annual Root Check

Late September is my preferred time for repotting. The plants have had a whole active growing season to build up their root systems, and there's still just enough warmth in the season for them to settle into new pots before going dormant for winter. Doing it in autumn means they'll be established and ready to take off again in spring.

The Inspection Process

I go through the collection methodically. I check each pot from the bottom — roots visibly growing out of the drainage holes are the clearest sign it's time. For plants in plastic nursery pots, I also gently squeeze the sides: if the pot feels completely rigid and packed solid, the roots have filled all the available space.

This year the plants needing a size up were: the Philodendron Brasil (seriously rootbound), one of the larger Alocasia corm seedlings that has grown surprisingly fast, and the ZZ plant, which I honestly hadn't checked in about 18 months and turned out to have a comically overfilled pot.

Root Rot Inspection

Repotting season is also the time to catch root rot before it becomes a crisis. When I take each plant out of its pot, I look at the roots. Healthy roots should be white or light tan and firm. Mushy, brown, or black roots are rot. If I find any, I cut them off cleanly, let the cuts dry for a couple of hours, and then repot into fresh dry soil.

This year I found early-stage rot on one of my smaller Alocasias. Caught it early — only a couple of affected roots — and I'm fairly confident it will be fine. That one is going into a slightly more porous mix than before as a precaution.