Q: As you can see from the photo, these arborvitae are in a sad state from snowblower damage and probably need to be replaced. What shrubs can tolerate having large amounts of snow blown on them? We like having the screening between the alley and our family room windows that these shrubs provide, but that’s also the only place to shovel or blow snow. — Beth P.
A: Evergreens, including arborvitae, spruce and juniper, are easily damaged from the force of snowblowers aimed against them. You can often see a swath of damaged foliage across the evergreens where the snowblower’s chute concentrates the force. Evergreen branches are also very susceptible to breaking under the weight of piled snow.
When there’s not much choice of where to put snow, non-evergreen deciduous shrubs are a better choice. Although it’s never ideal to blow snow against any shrubs, there’s less chance of injury on bare branches absent of foliage.
A good choice of shrubs that remain somewhat columnar is Fine Line Buckthorn, requiring only limited pruning to keep it narrow, and it's available from garden centers. Its height should provide good screening, and it’s fully winter-hardy in zones 3 and 4. A row of these might make a good replacement for the arborvitae, and they’ll at least provide some semblance of screening, even when not in leaf.
Q: With the dry conditions and warm weather this spring, is it OK to start watering my trees? — Sean J.
A: Yes, absolutely it's fine to water trees, shrubs and other plantings now. It’s best to water deeply and less often, which can be accomplished by letting the hose slowly trickle over the ground surrounding the trees.
If given a good soaking, established trees will be fine if watered every two weeks in the absence of rain, or once a week for younger trees planted within the past year or two. Frequent light sprinklings should be avoided, which cause shallow roots and are a waste of water.
Q: I planted bluegrass seed last August, which grew and established well before winter. Now with the dry conditions, should I start to water it? If so, how often? — Doug P.
A: If dry conditions continue, the lawn would benefit from watering. On established lawns, water deeply and less frequently. Lawns benefit from 1 inch of moisture, either from rain or irrigation, once per week, in one application.
Deep watering encourages a deep root system that is able to withstand adversity. Frequent, shallow sprinklings encourage shallow roots that are less able to remain healthy in times of drought.
To gauge the amount of water being applied by a sprinkler, a straight-sided soup can placed on the lawn is a good way to monitor whether you’re leaving the sprinkler on long enough in one spot. Watering deeply and less frequently conserves moisture and creates a healthy turf.
Q: We live on an old North Dakota historic homestead and would like to find and plant rose varieties that would have been found on homesteads of the 1897-1910 era. We’re hoping you might know of some of the varieties that were planted about that time, and where I might buy them, if still available. — Sherwood G.
A: Luckily a number of the shrub roses that were popular in pioneer days are still on the market and can be useful in today’s landscapes. Many of these are in a species called rugosa roses and can become quite large. They are fully winter-hardy and very thorny, and do benefit from pruning every year or two.
Roses planted by early homesteaders include Hansa, Harrison's Yellow, Persian Yellow, Father Hugo, F.J. Grootendorst and Sir Thomas Lipton. A few others were also used, but aren’t still available in the nursery trade.
The best sources are independent, locally owned garden centers. Few garden centers will carry all the types listed, but might have one or two, and by shopping around you can add to your collection. I’ve also found them from mail-order catalog sources.
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.