Midway through repotting a procumbens juniper, I found that the center of the rootball was dry. This is common when a tree has gone too long without repotting. Even heavy and frequent waterings – or incessant rain – may not be enough for the water to soak the entire rootball. Rootball with dry center Finding…
via Improving drainage in a compacted rootball — Bonsai Tonight
Eastbourne & Wealden Bonsai Club 