|I recently planted Boston ivy in a rather shallow planter box on my roof deck (the tops of its roots are exposed). It is a tall plant that I was hoping to train along a concrete wall. But rusty brown spots have begun appearing on many of the leaves, and some of the vines and suckers are withering and break off easily. I don't see any bugs on the leaves. Is this a problem of soil depth, watering, disease? How can I fix it?|
|Virginia Creeper or Parthenocissus quinquefolia is a large vine, growing to at least 30 feet, so a shallow planter is not likely to be large enough to allow it enough root space to be healthy. In addition, not only is planting it with roots exposed extremely stressful to the plant -- but leaving the roots near the crown exposed is quite likely to kill it. Whenever roots are stressed, the top growth will suffer and reflect the stress. That would explain the wilting and die back.
This plant is occasionally affected by leaf spots, and a stressed plant is more likely to suffer from additional problems such as pests and diseases. At this point, I would suggest you replant it into a larger, deeper container (perhaps a five gallon bucket) that affords enough space to set the plant at the proper planting depth. Keep the soil evenly moist but not soggy. This larger container will also be more easily protected during the winter when you have to insulate the roots from freezing. Next, to try to limit reinfection, remove the leaves showing spots and avoid overhead watering, especially in the evening. Try to increase air circulation as well if that is possible. Finally, neatly trim off any dead material.
Keep in mind that this type of perennial vine tends to grow slowly the first year, a bit faster the second year and then grow like mad the third year. Good luck with your plant.