Q I am worried about damage from the snow to my arborvitae and other evergreens. Is there anything I can do now to fix it?
A Many evergreen and deciduous shrubs have branches still weighed down by heavy snow remaining on the ground. If those branches are bent but not broken, I would recommend trying to gently remove the snow that is holding them down. The branches may not instantly recover, but may gradually return to their original shape by the time spring arrives.
Another reason to remove that snow is to lessen the risk of animal damage. Branches and stems still buried in snow are vulnerable to nibbling rodents, such as mice and voles, which use the snow as cover. Rabbits can also use the snow to reach up higher on the stem to feed. Girdled stems and branches, from which the bark has been stripped by such feeding, will not survive.
But that is all I would suggest doing now. If you have branches that have been snapped or broken by the snow, wait until early spring to carefully prune them out. It won’t hurt the plant to wait. Spring is also a good time to evaluate if bent branches are going to recover; if not, they may also need to be pruned to restore the overall shape of the plant.
Arborvitae shrubs often have multiple leaders, or central trunks, that may have been severely bent or broken by the snow. Removing any remaining snow now may give the plants time to recover by spring if the damage is minor. Come spring, broken leaders and branches should be pruned out; if you can reach them, bent leaders can be gently tied together with a flexible tape to help them regain their form. This binding should be removed within a year. For larger trees, you may need the services of a certified arborist to do some restorative pruning and cabling.
Of course, if we get more big snowstorms, we may see more extensive damage. A combination of high winds, more heavy snow, and soil that is soft and saturated from melting snow may lead to not only broken branches but entire trees uprooted. I noticed that kind of damage on a recent trip to the Washington, D.C., area.
Q I would like to have more ferns in my garden, but I have trouble getting them to grow well. I’ve been told they require acidic soil.
A Ferns have been around for more than 200 million years, so you know they must be durable and adaptable to a range of growing conditions. Not all ferns require acidic soil, as is often thought; although many ferns do prefer it, there are also many that prefer alkaline or limestone soils, and some that will tolerate a range of pH levels.
In Cumberland County, areas underlain by sandstone, such as North Mountain and South Mountain, have soils that tend to be more acidic, while the limestone in the valley creates alkaline soils. Ferns that prefer limestone soils include maidenhairs, hart’s tongues and bulblet bladder ferns, while most sword ferns, male ferns and lady ferns will grow well in a wide pH range.
Most ferns thrive in a rich soil high in humus that retains moisture but still provides good drainage; the best way to achieve these conditions is with the addition of compost to the soil at planting time and then a yearly topdressing of compost or leaf mold. The organic matter fertilizes as well; ferns tend to be intolerant of synthetic fertilizers. An organic mulch of pine needles, fine pine bark, compost or leaf mold will also help retain moisture and gradually add organic matter to the soil.
We also tend to think of ferns as plants that grow in deep shade where no other plants will thrive, and that again is a misconception. Most ferns prefer light or dappled shade, and there are even ferns that will grow in full sun. Given sufficient moisture, ostrich ferns, royal ferns, cinnamon ferns and sensitive ferns will thrive in full sun as well as light shade.
Deciduous trees in the garden provide the dappled shade or patches of sunlight that suit many ferns. But ferns are not good competitors with the roots of trees and other plants for moisture and space, so it is important for ferns to have enriched, cultivated soil in which to grow in the garden.
And although it is generally true that ferns need a good deal of moisture to grow well, there are ferns that tolerate dry conditions, and even some that thrive in rocky desert areas. There are ferns that will grow well in sunny dry meadows, such as hayscented ferns, or in the crevices of limestone outcroppings, such as cliff brakes. Even ferns that prefer abundant moisture are often tolerant of seasonal drought if they are well-established; they may go dormant, but will revive when moisture returns.
So, to grow ferns successfully, consider the shade, soil and moisture in your garden; and then try to match your chosen ferns to conditions that are similar to those of their native habitats.
Annette MaCoy is the consumer horticulture extension educator and master gardener coordinator for Penn State Cooperative Extension in Cumberland County. If you have garden questions, contact Annette at 240-6500 or by e-mail at email@example.com.