Great discussion. Peter's comment made me realize immediately one of the main problems with growing in pots, namely that there is no capillary action to speak of at all. A plant's roots will respond to the downward/outward hydrostatic principle but in pots this stops at the drainage holes, where there is drying instead of an "expected" refuge for moisture-seeking roots. The wicking effect only lasts a very short time after watering. Instead of root-encouraging water movement, in containers there is a drying effect from above and below and at the sides and the last region to dry out is toward the center of the rootball-- where feeder root development is poorest. This staleness or lack of proper water movement must account, in part, for the relatively poor performance of many species in pots that thrive when planted in the ground. One way to abate this problem is to keep plants more pot-bound than usual. This necessitates more frequent watering and keeps the cycle of air and water movement more brisk. Dylan Hannon