· John Heider's Answer
· Hi Marylynn-Before planting a Sky Pencil holly in a pot you want to make sure this plant will survive in your location during the winter months. Do you know what hardiness zone you live in? This holly is hardy in zones 5-9. When planting in containers it is best to figure using plants that survive in 1-2 zones lower as plants can be damaged much more easily than if planted in the ground. Potted plants can be moved to a more protected area during the winter. Wraping the containers with insulating materials can also be done if protection from freezing temperatures is needed. Wood, concrete, clay, and ceramic pots are much more beneficial as soil will not heat up and dry out or freeze as quickly as it would in thinner sided plastic pots. I would plant this holly in a large container with approximately a 23 to 26 inch diameter and a depth of approximatel 16 inches or more. Most 1/2 whisky barrels come close to these dimensions to give you an idea of the size I would use. Because in time this holly can get tall this size container will give it the stability it may need to withstand hard wind that could tip it over. This size should also give this holly the amount of soil it will need to survive for many years. The more soil the better as this will help to keep the plants roots from temperature extremes which can happen more so in pots than when planted in the ground. If you are planting a smaller size plant at this time you can place a smaller pot inside the larger one and in time as more space is needed the plant can then be transplanted directly into the large container.
Please ask if you have any other questions.