Can rabbits really chew up the lower half of shrubs?
Gardening columnist Don Kinzler also explains why tomatoes sometimes crack, and if it's OK to transplant a dogwood now.
Q: Our son in the Twin Cities planted arborvitae last summer, watered them well, gave them good care and they looked great in the fall. When the snow melted this spring, the lower half of every shrub was dead. They went to the nursery where they bought the shrubs and the nursery claimed rabbits did the damage and nothing can be done to undo it. How can rabbits chew up the shrubs at the same height on all the shrubs? We think there might be another answer and that's why I'm contacting you. What’s your opinion? — Doug A.
A: Thanks for sending photos. I do agree with the nursery — the injury is classic rabbit damage on arborvitae. The injury usually occurs in fall, winter or early spring when there is little other greenery to eat, and the soft foliage of arborvitae is like a fresh salad to winter-hungry rabbits.
It's typical for arborvitae to be totally stripped of foliage up to the point at which rabbits can reach. Sometimes they’ll eat higher if a snowbank gives them access.
Unfortunately, there’s little that can be done to repair the damage. Arborvitae are reluctant to send out new foliage once the greenery has been removed back to wood that’s old and bare. Often the only option is to wait and see what happens, hoping they'll send out some new growth.
The uneaten part of the arborvitae will continue to grow fine. In about 95% of these cases, maybe more, the lower part doesn't regrow, and on many older arborvitaes you can still see the bare rabbit-eaten sections for the remainder of the arborvitae's life, as the rest continues to grow upward. The lower part produces new growth in very few cases.
Protecting arborvitae with chicken wire fencing is usually the best way to prevent damage or further damage. Arborvitae are not only attractive to rabbits, but are also frequently attacked by deer.
Whether to remove damaged arborvitae is always a judgment call. I usually recommend waiting through the following June, and applying a water-soluble fertilizer solution (2 to 3 gallons per shrub) next May 1 with the hopes it will stimulate new growth in the lower area. If new growth doesn't sprout by late June of next year, it likely won’t.
Q: Many of my tomatoes are cracking. What causes it, and can it be prevented? — Kathy M.
A: Cracking sometimes creates a circular pattern around the fruit, called concentric cracks, and sometimes the cracks are longitudinally downward. The disorder isn’t a fungal or bacteria disease, nor any situation for which we can spray or apply any preventative products.
Cracking happens when the interior of the tomato grows more rapidly than the skin, causing the skin to burst in a crack formation. The most common cause of the growth spurt and resulting cracks is rain following weather that’s been on the dry side, which is common many summers.
Tomato cultivars vary greatly in their susceptibility to cracking. Types that are less prone to crack include Mountain Spring, Mountain Fresh, Big Beef, Celebrity, Jetstar, Park’s Whopper Improved and Super Fantastic.
Potential cracking can be mitigated somewhat by striving to keep moisture uniform around tomato plants by eliminating swings between dry and wet soil. Mulch helps greatly.
Q: When can we transplant a dogwood? — Betty P.
A: The season with the greatest measure of success will be in early spring before the dogwood begins new growth. If the shrub is large, it should be cut back by more than half at the time of transplanting. In a pinch, transplanting can be done in fall after several hard freezes have induced dormancy, but spring is preferred.
If you have a gardening or lawn care question, email Don Kinzler, NDSU Extension-Cass County, at firstname.lastname@example.org. Questions with broad appeal may be published, so please include your name, city and state for appropriate advice.