The most common reason for leaf loss is water stress - either too much or too little. Plants in containers can require more frequent watering than the same plants in the ground so watering can become a real issue. You'll want to water thoroughly but then allow the top of the soil to dry out slightly before watering again. I'd prune the wisteria back to remove the dead and dying leaves and to encourage healthy new growth. Adjust your watering and I think you'll see an improvement. Enjoy! |