· Brooks Wilson's Answer
· Hi Dave,
Sky Pencil Hollies are extremely susceptible to root rot. Over watering, or too much watering of the foliage can cause big problems with Sky Pencil Hollies.
If Cosco employees over watered the Hollies root rot could have set in before you took them out of the store. This is very common at the big box stores.
I've also seen Sky pencil Hollies get die back. Dieback is a non-curable disease that forms knots in the stems and branches of plants. This knot restricts the flow of water and nutrients to the stem.
Sky Pencil hollies are also susceptible to spider mites. To check for spider Mites hold a white piece of paper under the leaves where they turn from brown to green. Tap the plant to knock the spider Mites on to the paper. If you see little red specks crawling on the paper you will know that it is probably spider mites. Control of spider Mites can be achieved by spraying with Neem Oil. Neem oil is labeled to control spider Mites.
What you can do:
1- Return the dead Hollies and get a refund.
2- Prune all of the dead growth from the remaining Hollies. Prune at least 6 inches below the dead part of the stem.
3- Make sure that the Hollies were not planted below ground level. The top surface of the root ball should be exposed and be slightly above ground level with no soil piled on top. If this is not the case, you will need to raise the plants. Apply a thin layer of mulch over the root ball, but no soil.
4- Buy replacements from a local independent nursery that selectively hand waters their plants. In general, independent nurseries know more about taking care of plants, and as well can better inform you of how to take care of plants.
Hope this helps you out.