Driveway Plantings for the NJ Winter
The Dangers of Salt for NJ Driveway, Walkway, and Roadway Landscape Design Plantings
As winter rolls around and snow begins to fall, we are all familiar with the risks posed by freezing roads and walkways. The winter hustle begins, the shovels are out, the plows are on, and the salt begins to fill neighborhood trucks. These efforts on the part of local landscaping companies and municipalities help to keep your roads, driveways, and walkways safe for travel on foot and in the car. One issue that can easily be overlooked is the fact that salt, used to melt the winter ice, carries its own set of risks. For your NJ landscape design, the salt can potentially damage your plantings along the road, the driveway, and your walkways. Before I make some recommendations regarding plantings for the driveway and walkways, let’s take a look at the root of the problem and where we might find its solution.
First of all, salt, particularly the salt most commonly used for roads and walkways, is harmful to plants in a couple of different ways. The salt can damage soil around the plant, or it can damage the plant itself. The sodium in salt can damage soil. The sodium raises the pH, dries up or reduces the amount of water absorbed by the soil, and causes an increase in runoff and erosion. It creates a drought for the plant during winter, when many plants need all the moisture they can get. For plants, the salt can cause damage through a spray onto the surface of the plant or by being absorbed by the plant roots. Without getting into specifics, dangerously high salt levels can severely damage a plant; surface salt can also create problems by interfering with essential functions.
How can you tell if your landscaping has been damaged by salt? This is probably the most relevant question you can ask yourself. Reduction in growth, foliage discoloration, thin crowns, nutrient deficiencies, and smaller flowers can all represent some salt damage. The key to determining salt damage as the diagnosis for these symptoms requires some detective work. If the damage comes from the spray of salt, you will mostly see symptoms on the driveway or road side. If the salt damage is a result of soil damage, you may want to look into a soil test. In general, salt damage may look like drought or root problems, but plantings along the driveway, road, or walkways should raise a red flag concerning salt. You will probably notice these symptoms in early spring, or in some cases, late winter.
Now, what is the overall best solution for a salt-tolerant landscape? Do not plant in the areas exposed to salt! If you have the space, the best option is to install grass for the first 15-20’ off a street curb and 10-15’ off your driveway curb. For walkways that will be salted, set your plantings back 3-5’. During the warmer months, this space will actually be perfect for annual pockets. Unfortunately, sometimes the salt exposure is practically unavoidable. If you have a more elaborate design or a small space that is exposed to salt, then you’ll want to pick from a list of salt-tolerant plants, which I will provide in the following paragraphs.
Let’s consider some good planting ideas and options along the driveway or walkway, assuming you live in New Jersey or some area where you get freezing temperatures. (If you live in Hawaii and you are reading this blog, I admire your curiosity.) Interestingly enough, plants are most tolerant or resistant to salt in early winter, but that doesn’t mean you can afford to forget about them. In addition, new, young plants are much more prone to salt damage. There are many different plants with varying salt resistance, so I cannot name them all. I can provide a brief list for some driveway landscaping ideas though.
For the salt-tolerant driveway and walkway landscape design, consider: white spruce, birch, white ash, sweet gum, swamp white oak, northern red oak, Japanese tree lilac, fragrant sumac, rugosa rose, common juniper, mugo pine, creeping juniper, spirea, moonshine yarrow, miscanthus, other ornamental grasses, day lily, bearded iris, becky Shasta daisy, creeping phlox, stonecrop, nepeta, thyme, and vinca. That should provide enough planting options to accommodate your salt concerns, whatever your situation may be. Most of these are really the most tolerant of any salt-tolerant plants.
If, instead of avoiding the salt or utilizing salt-resistant plantings, you would like to protect your existing landscape design materials, there are a few ideas and methods for doing so. If you are concerned about the salt spray, put up something to block it from your precious plantings. On a warm day in winter, rinse off the plants to try to get rid of any residual salt. For salt that seeps into the soil, utilize raised beds to avoid salty runoff into the soil. Also, do not shovel paths and driveways onto your plants. Whenever you can, opt to use sand instead of salt, and try not to use salt late in winter when the plantings will be most vulnerable. Lastly, to protect your winter landscaping efforts, use a lot of water in early spring to help the plants come back strong out of winter. Once again, I must stress that the best way to avoid salt problems is to avoid planting in areas susceptible to salt. Keeping a safe distance from walkways, driveways, and roadways is the most full-proof option.