Category Archives: Seasonal Landscape Tips

PROTECTING TREES IN WINTER

Even though trees go dormant in the winter, there are a few things that we can do at this time of year to keep them healthy for years to come.

  1. WRAP YOUR TRUNKS

You may have seen vertical cracks in the trunks of trees.  These are called frost cracks, and can result from varying temperatures on the tree trunks in the winter.  Thin-barked trees, such as maples, are more susceptible to this.  You may also have noticed damage due to browsing  or rubbing by wildlife such as deer, rabbits and voles.  All of these can cause significant damage, and may even be fatal to a tree, especially when young.

TIPS:

  • Install trunk guards as close to the ground as you can, even digging it a couple of inches into the ground if possible to protect against voles.
  • Extend trunk guards about 4’ tall to protect against deer and any small animals that may stand on top of snow drifts in winter.
  • For multi-stem trees or trees with low branches, try making a cage out of hardware fabric as an alternative to trunk guards.
  • Remove wraps in Spring to allow for air circulation and new growth.
  1. PREVENT WINTER DRY-OUT

Many evergreens in our area are susceptible to winter “desiccation”, or drying out.  You will typically see this on portions of the plant that are most exposed to winter wind, and will generally see damage starting at the tips of the branches.  There a few things we can do to help prevent this.

 

TIPS:

  • Water evergreens right up to the first frost, especially new plantings that may still be establishing root systems.
  • Wrap evergreens in burlap to protect against winter wind.
  • If salt spray is also an issue, use stakes with burlap to prevent direct contact with the salt soaked fabric.
  • Ask about anti-desiccant sprays at your local garden center.
  • Remove burlap as soon as possible in early Spring to allow sun exposure and air circulation.
  1. TO PRUNE, OR NOT TO PRUNE?

Winter is an ideal time to prune many trees.  However, winter pruning can affect flowering and may contribute to “bleeding” sap in some species.  There are also many proper pruning techniques to keep in mind when pruning trees.  When in doubt, contact an arborist.  However, here are a few guidelines to keep in mind.

TIPS:

  • Have your oak trees pruned in winter to help avoid oak wilt.
  • Clean, disinfect and air dry pruning tools regularly.
  • Always prune back to a bud or a branch—do not leave stubs.
  • Do not attempt to prune anything within 10 feet of a power line.

 

How Winter Salt Affects Your Landscape

Winter in Wisconsin offers plenty of opportunities for outdoor enjoyment! Skiing, sledding, ice skating and more keep us active outside for the winter season. Not to mention we have holidays to look forward to in winter and plenty of family time! With so much excitement, it is easy to forget about your landscape. What is going on under all of that snow, anyways? Well, one major consideration for your landscape is deicing chemicals, especially “rock salt” or sodium chloride.

Sidewalk and street salt, while necessary to keep driving conditions safe, can be detrimental to some of our common ornamental landscape plants, not to mention our cars, our pets and even the paving surface itself. It is always a good idea to minimize the amount of personal sidewalk or driveway salt used to protect your pets, vehicles, plants and property. If possible, use sand or calcium chloride products rather than sodium or magnesium products to reduce damage. Even when we minimize the amount of winter salt we use personally, we still need to consider salt from public streets.

In regards to landscape plants, there are two types of salt damage to be concerned with – aerial salt and soil salt. Soil salt levels can be very high in areas adjacent to streets, walkways or driveways, especially where plowed or shoveled snow is dumped. Aerial salt can be an issue near highways or heavy traffic streets, where salt spray is evident.

If you have noticed any of these signs, you may be noticing the symptoms of salt damage:

Signs of Salt Damage

Aerial Salt

  • Bud and twig dieback
  • “Witches Brooms” or unsightly clusters of twigs sprouting from one location
  • Late or poor bloom/leaf out in Spring
  • Small or off-colored leaves
  • Brown leaf margins
  • Signs of damage most evident on side of plant facing street or source of salt spray

Soil Salt

  • Plants “dry out” more easily
  • Nutrient deficiencies in soil, especially magnesium and potassium
  • Off-colored, often yellow leaves
  • Stunted growth
  • Brown leaf margins
  • Potential plant death, especially in turf or smaller perennials

Once you have identified a problem with soil or aerial salt, there are a few things you can do to minimize the negative effects.

If you notice problems due to high salt levels in soil, it is beneficial to minimize the amount of sodium chloride exposure in those areas. Try using calcium chloride, or if you must use sodium chloride, mix a small amount with sand. If you need to replace plants in those areas, choose plants that have demonstrated a higher level of tolerance to soil salt. A few good options in our area are shrub roses, daylilies, hostas, some ornamental grasses such as Karl Foerster Reed Grass and junipers.

Problems with aerial salt spray are often more difficult to prevent. Try to plan accordingly and use salt tolerant plants in areas that are exposed to heavy salt spray. In some cases, burlap can be used in winter to create a barrier to protect plants. If you choose to use burlap for this purpose, be sure to maintain an air gap between the burlap and the plant. If the burlap becomes saturated with salt spray and is in contact with the plant, damage can still occur. A fence or salt-tolerant hedge near the source of the salt spray can sometimes help to reduce damage to plants in the rest of your yard. Upright Juniper and Ponderosa Pine are two good options for this. Salt spray can travel quite a distance into the air and away from its source, especially from higher speed roadways. Choose salt tolerant trees if you live near a highway or high speed traffic. Honeylocust, Cockspur Hawthorn, and Japanese Tree Lilacs are among the trees most tolerant of salt spray in our area.

To simplify a complex issue, remember that salt water makes us thirsty, and it makes our plants thirsty too! High levels of salt in the soil, or directly contacting your plants can absorb water that would otherwise be used by your plants. Your plants will very likely have to deal with some salt issues each winter, but by following these tips you can minimize the negative effects of deicing products. Start preparing in fall by giving your plants plenty of water to prepare for winter. In spring, try not to wash slush or salt from the sidewalks into your yard or planting beds. Enjoy your winter wonderland and healthy plants next spring by using salt products responsibly and following these landscaping tips!