While pawpaw trees in the ground are quite cold hardy (hardy to -25F/ -32C), pawpaw roots in potted trees are sensitive to freezing. Pots left unprotected outdoors can freeze solid, killing the roots. However, pawpaws are a temperate deciduous tree, and have a requirement for chill hours in winter to satisfy their dormancy and chill requirement. This is estimated to be approximately 400 hours between 32-45F (0-7C), but KSU is currently conducting studies looking at chill requirements of different cultivars.

The ideal place to store potted pawpaw trees over the winter is somewhere cool (32-45F / 0-7C) but not below freezing (a short time at a few degrees below freezing is ok, but extended periods in the 20s or below will freeze pots and roots). A walk-in cooler, unheated garage, shed, or root cellar are ideal; or outdoors with pots placed together directly on the ground and surrounded with straw and covered with a tarp; or bury pots outdoors. Allow trees to lose their leaves naturally for fall before covering or storing. Water trees well before storing for the winter; and check during the winter for dryness. Dormant trees do not use much or any water, but the pots should not be allowed to dry out enough that the roots dessicate. Often potted trees do not need to be watered during overwintering but depending on the temperature and humidity they may.

Trees can be uncovered or brought back in to a greenhouse or other warm environment, or planted, in the spring. Water well immediately after uncovering, moving, or planting trees.

Pictured: potted pawpaw trees at the KSU Research and Demonstration farm being overwintered in cool headhouse. Thermostat is set at ~35F to prevent freezing.

The original Facebook posting on this topic appears on the ‘KSU Pawpaw‘ page.