Q: Porcupines have been eating the bark of this flowering crab apple tree over winter. How can this be repaired to save this beautiful tree? — Sharla P.
A: Although your tree is very beautiful, my first reaction to the photo is that it could use a good pruning, which might be accomplished as a side benefit of removing the branches damaged by the porcupines. The tree’s branches appear crowded, and thinning out about half of the inner mass of small, thin and crisscrossing branches will help the tree's health, which is important for both ornamental and fruiting varieties of apples and crab apples.
The porcupine appears to have totally stripped off the bark down to white wood on several branches, which will likely die from the point of damage outward. Unfortunately, there isn't anything that can be applied that will cure damage like this. The branch’s growing tissue, called cambium, is a thin layer directly below the outer bark. When damage extends into the white wood, the cambium layer has usually been destroyed, and no sealers or pruning paints will replace it.
You can delay the remedial pruning until the tree is beginning to leaf out. Newer recommendations about the timing of apple and crab apple pruning suggest that black rot, which is a common problem in these tree types, might be lessened by delaying pruning until leaf growth begins.
Sometimes damaged branches will begin to leaf out, but then go downhill quickly. From what I can see, pruning out the damaged branches will still leave a nice tree, and thinning out the branches might keep it flowering in good health. I'll keep my fingers crossed for you.
Q: I planted Kentucky bluegrass seed last August, and it produced a good stand before winter. Now with the dry conditions should I start to water it? If so, how often? — Doug.
A: If dry conditions continue, the new lawn would benefit from watering within the next week or two, with the warm, windy conditions we’ve had. For established lawns, water deeply and less often to create a healthy turf. Lawns benefit from 1 inch of moisture, either from rain or irrigation, once per week in one application.
Watering deeply, and less frequently, encourages a deep root system that helps the lawn thrive, even in adversity. Frequent, shallow sprinklings encourage shallow roots that are less competitive with weeds and less able to utilize subsoil moisture.
To monitor the amount of water being applied, place a straight-sided soup can on the lawn within the sprinkling zone.
Q: I know the calendar says it’s early, but the thermometer and the fact there is no snow tell me it’s an early spring this year. Is there any downside to mowing my lawn the first week of April? It’s dry enough. — Steve S.
A: There's no downside at all to early mowing. I like to give the lawn a short cut in early spring before the grass begins to green up. An early mowing reduces the old brown grass before new blades start appearing.
Q: I kept my gladiolus bulbs in the refrigerator over winter. When should they be planted outdoors? — Birgit P.
A: Gladiolus corms should wait until the first half of May to be planted, even if spring seems early. If they emerge from the ground too soon, the leaves can be frozen, because the likelihood of frost remains high until mid-May.
If gladiolus are planted about May 1, it takes 10-14 days or more for the leaves to emerge above ground, helping them to escape frosts that happen in the meantime. Planting corms at weekly intervals extends the summer blooming time of gladiolus, instead of planting all at once.
If you have a gardening or lawn care question, email Don Kinzler, NDSU Extension-Cass County, at email@example.com. Questions with broad appeal may be published, so please include your name, city and state for appropriate advice.