We have a rose of Sharon bush and it died suddenly. It is 6 to 7 years old, and showed no signs of stress. In fact, last year, it had the most beautiful blooms ever. What could we have done to prevent this? We have 2 more of these bushes, and would hate to see this happen again! They get sunlight until late afternoon, and we are on sandy soil.

Every year the onset of spring brings with it different changes to our gardens. We can expect occasional winter die back of branches on rose of Sharon (Hibiscus syriacus). With careful spring maintenance pruning to remove the dead wood, we will still enjoy a multitude of flowers that are produced on this year’s growth. While the past winter was very cold, death is seldom the result of one problem, but a combination of conditions over the life of that plant. The best defense you have is to always remember “right plant right place,” improve watering and fertilizing practices, and keep an eye out for insects and diseases that can stress a plant and leave it vulnerable to winter kill.

I have neglected trimming some juniper tams under our dining room window for several seasons. They are now over 6 feet tall. Can I cut them back nearly to the ground and expect them to regrow? They have no foliage under their outer surface growth.

Junipers will not tolerate heavy pruning because they do not have latent buds below the foliage area in older wood. If branches are pruned back to older wood with no foliage, the branch stub usually dies. This fact makes it important to choose a variety of juniper that has a growth habit and mature size that will suit the planting area you have selected. The growth habits of junipers vary from low-growing ground cover varieties to large conical-pyramidal forms. You might just want to replant the area with a more suitable juniper that will require much less maintenance pruning.

I have a bed that was installed with landscape fabric (to prevent weeds) and rocks for mulch. Can perennials in the bed still spread invasively?

Perennials that are invasive got that reputation because they go where they want and take no prisoners. The landscape fabric may challenge them for a time. But most invasive species do their dirty deed with rhizome type roots. The fabric will keep them warm, trapping moisture, allowing them to run until the root finds a weak point. To avoid this problem, plant perennials with a clumping habit rather than a running one. Avoid those that offer “quick coverage” or those that boast “self-seeds.” That seed will sprout in the crevices between your rocks, and the roots will work through the fabric. Remember that landscape fabric is a woven plastic material that allows air and water to pass through. Weeds need sunlight to germinate. The fabric effectively prevents that. The fabric may retard the individual growth of perennials planted through the holes cut in it, but it will not prevent invasive plants from following their natural habit.