It's fall, time to hunker down with a hot beverage in front of a warm fire. Before you don your fuzzy slippers and get too cozy, consider a few to-do items to ensure a healthy landscape come spring. Your focus this time of year should be on these 3 P's:
1) Prevention of winter burn, sunscald and frost cracking.
Protection from Winter Burn:
Midwest winter winds are not only frigid but are drying as well and can lead to winter burn. Those dry winds cause moisture loss in the foliage of evergreens but the ground is frozen so roots are not able to take up the necessary water to replace that loss. The result is the browning of needles, starting at the tips and if bad enough it can kill entire branches or even the whole plant. Often you don't notice this problem until it's too late. Remember, you can't water once the ground is frozen. Your best course of action is to make sure your transplants are well watered up until the ground is frozen. Even established plants may need a boost of water before winter if we've had a dry summer or fall. While evergreens are the most susceptible to winter burn, remember to also water your deciduous trees and shrubs as well through the fall. Another method to protect your plants (evergreens in particular), is to wrap them in burlap over the winter or apply and anti-desiccant such as Wilt-Pruf periodically to the foliage. Sometimes if the winter is bad enough, you can't avoid winter burn completely. In the spring if you notice your evergreens are not "greening" up like they should, try a fertilizer that is high in iron to help them recuperate.
Protection from sunscald/frost-cracking:
Young tree trunks are often injured in winter due to fluctuating day-to-night temperatures. During the day the sun quickly warms up the south and west facing sides of trunks, but at night the temperatures drop back down causing expansion and contraction of tissues that lead to cracking of bark and transport tissues of the wood. Thin-barked species like Maples, Oaks, Linden, London Planetree and Willows are most susceptible. An easy solution is to shade the trunks in some manner. There are many ways to do this but for most people, wrapping the trunk is the most feasible. Burlap or opaque white plastic work well or you can find a specially made cardboard-like tree wrap at a local garden center. Porous materials are best to avoid unwanted moisture buildup. Don't use anything solid black as it will only facilitate the build up of heat that you are trying to avoid. Remember to remove any wrapping in the spring and whatever you use to adhere the wrapping material, should not gouge into the trunk.
Late fall and winter is an ideal time to prune most trees and shrubs. Pests and diseases are dormant and therefore there is no threat of infestation through freshly made cuts. Once the leaves fall off, it is much easier to see branching structure and to make decisions on what to cut or keep.
With any newer transplant, avoid doing much pruning at all. You don't want to run the risk of reducing vigor this early in the game. Do go ahead and remove problematic issues like, broken or dead branches, crossing branches that rub together or rub the trunk, and address double leaders. After 2-3 years you can begin structural pruning. Selectively prune out branches that come out of the trunk at odd angles or side branches that grow towards the center of the tree. Be on the look out for water sprouts (fast growing, energy zapping whips that grow straight up from branches or trunks). Don't remove too much material at one time, pruning should be a year to year process.
Critters of all shapes and sizes can do a lot of damage in a little bit of time. As food sources dwindle they will find their way to your trees and shrubs. Protect your investments. Trunk protectors are highly recommended to skirt the effects of antler rubbing or bunny chewing on your trees. In Iowa it's not uncommon for bucks to begin rutting in mid-August, so apply your trunk protectors early. Whatever you choose as your protection, make sure that no materials like straps or ties ever gouge into the tree. We recommend you avoid using black plastic drain tile as you don't want to build up daytime heat that could cause frost cracking. If your trunk wrapping material is not porous, remember to remove it promptly in the spring to prevent moisture buildup so you do not develop problems with fungus, bacteria or insects.
Your small trees and shrubs are a little more difficult. The only way to ensure a deer or rabbit will stay away from them is to fence them in. You can fence shrubs individually or in groups. Deer are quite tall so you either need to construct a high cage or opt for a low cage with an extra piece of fencing draped over the top.
For added insulation, apply an extra thick layer of mulch. We recommend 4"-6" deep layer of hardwood mulch to do the trick.
Remember to periodically check that any staking, fencing or protective materials are not damaging your trees. After a few years your tree's bark should be thick enough to tolerate the occasional deer and sunscald shouldn't be an issue.