I bought a propagator and took over 20 Hydrangea cuttings and they have now rooted….when do I increase airflow in propagator or move them to larger pots in my (new) greenhouse?
Normally, when roots are seen coming out of the bottom of the tray or the pot, the cover can be reduced over a period of a couple of weeks to harden off, and then the cover is removed.
After about four weeks, the root cuttings are usually advanced enough to pot on carefully into half soil half compost with some slow-release fertiliser granules added.
But if the summer and autumn are gone, it is often best to leave the cuttings undisturbed until March, when they can be potted on at the first signs of new growth.
Water carefully at this stage … not too much and cover with a sheet of polythene for a few days to allow the roots to settle. You will see the young plants perk up.