As spring arrives, do you notice that leaves and evergreen needles are browning at the tips and margins? If so, it’s probably a case of winter salt damage to your trees and shrubs.
One of the worst parts of winter can be the ice. We tend to complain about the snow and the cold, but there’s nothing scarier than slipping on a sheet of ice – whether you’re on foot or in a vehicle. Using some kind of ice melt or road salt has been a common solution to the dreaded ice on sidewalks, walkways, and roads, but, like most things, it comes with its own set of issues – ones that you may not even realize are happening.
The problem occurs when the ice and snow melt and the salt-contaminated water soaks into the ground. Underground, your plants, trees, and shrubs all absorb the water, along with the salt or ice melt.
This can lead to problems (and even death) for your plants. Commonly known as salt damage, it looks very similar to water stress. Needles on conifers begin to turn brown at the tip, and deciduous trees have leaves that turn brown or die completely.
Why is salt dangerous to plants and trees?
Compare it to this: how would you feel if the only water you were able to drink was saltwater? Not so great, right? It’s even worse for plants. The salty water moves throughout a plant or tree’s vascular system before it’s pushed out through tiny pores on the leaves. The salt collects on the leaf (or needle) edge and kills the leaf tissue, which is why you may notice browning or yellowing at the leaf tips first.
Additionally, spray from road salt can affect trees. You may notice it on shrubs or trees that line the edge of a road – the side that faces the road looks scorched and damaged, while the other side looks perfectly healthy. This is often from the water sprayed by vehicles as they drive past on salt-treated roads.
No matter how road salt or deicers reach your plants or trees, it’s not good for them.
How do I protect my plants from winter salt damage?
There are several ways to protect your plants and trees from salt damage.
Water well to remove salt from the soil
While it won’t do much good when the ground is frozen, once you notice the snow melting (or while temperatures are higher), you can irrigate or leach your soil with water. This lowers the concentration of salt in the soil near plant roots.
Don’t spray a lot of water at once; instead, irrigate slowly and for a longer period of time. This will ensure that the water reaches the roots without causing any undue erosion.
Rinse the leaves/needles
Especially in areas where road spray is an issue, wash off the plant or trees as often as you can. Again, wait until temperatures are above freezing, otherwise you will cause ice to build up on your trees, causing a whole other set of issues.
Wrap vulnerable trees and shrubs in fall
Burlap and other materials can protect trees and shrubs from salt spray, but remember to unwrap them in spring. Keep in mind that while this protects your plants from spray, it doesn’t prevent salt from leaching into the soil, so you may want to irrigate as well. Learn more about wrapping trees and shrubs in this blog post.
Contact us to apply anti-desiccant spray
Some plants, such as rhododendrons, boxwoods, and hollies, can be protected using an anti-desiccant spray. It is primarily used to prevent shrubs from drying out during the winter months, but it has the added benefit of coating the leaves and providing some protection from salt.
Anti-desiccants need to be applied before temperatures drop and before the ground freezes, so be sure to get on the schedule next fall if you want this treatment.
Be aware of where your snow piles are
If you or your neighborhood uses some kind of ice melt, keep your snow piles away from any plants or trees.
When will I notice signs of salt damage?
You probably won’t notice it in the middle of winter, but rather when plants begin to pull water from the soil in spring and summer. However, some damage from salty soil can take years to appear, depending on the concentration of salt and other factors.
How can I prevent salt damage in the future?
Use alternative ice-melts
Road salts are usually sodium chloride (rock salt or table salt) or calcium chloride (a salt from limestone). These are the types of salts that are most harmful to plants. A less corrosive option is CMA, or calcium magnesium acetate. You can also use abrasive materials for traction, such as sand, kitty litter, crushed rocks, or ash. If ice melt products are still needed, try using a smaller amount mixed with one of the items used for traction.
Plant salt-tolerant plants
Some plants are more salt-tolerant than others, so if one area of your yard is often affected by salt spray or salt soil damage, you may want to replace plants with a more salt-tolerant variety.
Many nurseries will label plants that are salt-tolerant, and the list of trees below will also be helpful in choosing the most tolerant trees for your yard.
If you have questions about which types of trees would do well on your property, just give us a call.
Trees Tolerant of Salty Soil & Salt Spray
Acer griseum, Paper-Bark Maple
Aesculus hippocatanum, Horsechesnut
Aesculus pavia, Red Buckeye
Betula nigra, River Birch
Betula papyrifera, Paper Birch
Catalpa speciosa, Catalpa
Celtis occidentalis, Hackberry
Cercidiphyllum japonicum, Katsura Tree
Chionanthus virginicus, White Fringetree
Crataegus crus-galli var. inermis, Thornless Cockspur Hawthorn
Ginkgo biloba, Ginkgo
Gleditsia triacanthos, Honeylocust
Gymnocladus dioicus, Kentucky Coffeetree
Juniperus virginana, Eastern Red Cedar
Koelreuteria paniculata, Goldenraintree
Larix decidua, Common Larch
Liquidambar styracifula, SweetgumMagnolia virginiana, Sweetbay Magnolia
Nyssa sylvatica, Black Gum or Tupelo
Picea glauca var. densata, Black Hills Spruce
Picea pungens, Colorado Spruce or Blue Spruce
Pinus thunbergiana, Japanese Black Pine
Populus alba, White Poplar
Quercus alba, White Oak
Quercus macrocarpa, Bur Oak
Quercus palustris, Pin Oak
Quercus phelow, Willow Oak
Quercus robur, English Oak
Quercus rubra, Red Oak
Robinia pseudoacacia, Black Locust
Syringa reticulata, Japanese Tree Lilac
Taxodium distichum, Bald Cypress
Thuja occidentalis, Arborvitae
Tilia tomentosa, Silver Linden
Ulmus Americana ‘Princeton’, Princeton Elm
What should I do if I suspect serious salt damage to my trees or plants?
If you have followed the steps above and still notice significant damage, contact the arborists at Arbor Experts to schedule an assessment. You can also send us a picture of the suspected salt damage for diagnosis. If your trees or plants are badly damaged, we can recommend a course of action to help them recover. But if the damage is too extensive, we may have to remove the tree for safety purposes.
Winter in Dayton is a delicate balance of keeping yourself and others safe from slips and falls on icy surfaces and keeping your plants and trees safe from salt damage. We hope this article has shed some light on things that you can do to keep your yard healthy and thriving all year long.