Roadsides become seasides for plant ecosystems; Celebrity chefs make salmon and grapefruit salt while Ghana salts its fish raises cardiovascular illness risk
By Gregory Jackson
(Photo: Larder Master Jeremy at Trentina in University Circle in Cleveland, Ohio. Part of Chef Jonathon Sawyer’s culinary team, making salt flavored with grapefruit, tomato, fish head, chanterelle, and lobster roe; shared on Jonathon Sawyer’s Facebook January 24, 2015).
Shopping at Walmart (WMT) for rock salt, especially if you live in Cleveland, Boston, New York, or Chicago and other states nearby may be sold out. Salt is salt and I experimented with using iodized table salt, the same salt you would use as a pinch for cooking.
“No, you can’t use regular table salt for your driveway,” said a Walmart associate. “You’re better off going to CVS or Discount Drug Mart.”
When salt dissolves into runoff it will either end up in waterways or your soil. To help reduce salt runoff from your property you can benefit by purchasing regular salt (iodized is optional) and practice methods to minimize salt concentration caused by water flow.
Salt results in freezing point depression, melting occurs faster than freezing because of an ice/salt mix rather than just water. However, whether you are adding rock salt, table salt, sand, or other organic material salting is meant for ice cracking and breaking to later be shoveled off, not to completely melt ice. Choosing the later alternative increases the risk of “brine” during a melt or rain – the salt dissolves in the water and rinses into your soil or down your driveway into the sewer – affecting the health of your soil in the spring and affecting aquatic ecosystems. Rock salt is more corroding on foundational work and tracks inside your home. Therefore, even if you were not able to buy rock salt but purchased iodized salt instead, the brine in your runoff melt will contain a beneficial nutrient where vegetable plants can use.
Even if you are careful to not allow runoff to affect your growing beds, if you use traditional fertilizers they add unwanted salts, too.
When tomato plants were planted in soil with sodium chloride (NaCl) the plants can survive in soil with less than 5.75 percent concentrate, but even then their height was stunted by at least 50 percent than tomatoes they just added water, according to Sara Brewer, Stacy Larsen, Amnessa Morey, and David Wickham of Portland Community College. At 11.5 percent and 23 percent (the industry standard for de-icing concentrates by transportation departments and other commercial icing professionals), those tomatoes died after one treatment. The reason why too much salt is bad for plants is salt inhibit the ability to uptake potassium, calcium, and phosphorous, not to mention osmotic stress and cytoplasmic toxicity (not getting enough water).
De-icing solutions less than 23 percent will cause road surfaces to refreeze.
If you desire growing near your winter salted surfaces and you suspect your soil may have concentrated salinity, there are three ways to manage saline soils according to the Colorado State University Extension applied to semi-arid climates since salty soils are inevitable in drier regions.
First, lower the salt below the roots by applying more water to move salt below the root zone. Secondly, establish good drainage. An excellent way to improve your soil’s drainage is to add compost preferably with shells to naturally improve soil drainage.
Shells or roughage you used to create compost that is often sifted out should stay. Do not sift. In fact, Groundz encourages all our urban farmers, customers of our compost, and composting advice to use “homemade” looking over perfectly sifted compost.
Adding shells, twigs, and other material like partially broken down leaves will function as “structure” in your soil to allow drainage underneath roots.
Thirdly, salt in your soil can be moved with intermittent watering and strategic placement of digging holes below the waterline. However this last method usually applies to those living in arid to semi-arid regions like deserts.
Salting your driveway with iodized salt, iodine loss in soil is rapid, minutes to hours. The rate of sorption (solubility) increases with organic material added to the soil is better than lingering salt concentration accumulation; there is a variety of mineral content on your driveway requiring less salt, but provide more traction. Even in soils with salt build up, crop rotation and compost could help.
Under salt accumulated soils consider salt loving plants that can uptake salts from the soil first, some legumes like beans may work. Barley is sensitive to salts and iodine in the soil, it will die. However sugar beets especially like iodine in the soil, which may help it survive salinity.
When iodine is added to salt, this micronutrient makes thyroxine and triiodothryonine hormones biosynthesize by the thyroid gland. If this micronutrient is lacking, goiter and some developmental disabilities may result. On the other hand, too much salt is unhealthy.
In Ghana, during medical mission’s trips to establish a new clinic and wellness center, missionaries discovered fisherman packing their fish in salt to preserve them. Since they have no refrigeration, salting their fish is essential to keep from spoiling. Ghanaians have been known to have cardiovascular illness. Freshly caught and served or refrigerated cod is a great source of iodine. Other excellent sources of iodine naturally found in seafood like sea bass, haddock, perch, shrimp, and tuna. Boiled egg, cow’s milk, cooked Navy Bean, baked turkey breast, bake potato with peel, dairy, seaweed; and plants grown in iodine-rich soil.
Foods rich in iodine are also rich in iodine when they break down in compost. When we compost Merwin’s Wharf food trimmings for Cleveland Metroparks, we compost fish waste like salmon, cod, perch, and crab shells – when we mix those with leaves, dead plants, and other compost material – the compost becomes a rich source of iodine, which you would later add to vegetable beds.
Over 50 years of indiscriminately salting Ohio roadways has turned roadside ecosystems resembling more like ocean and coastal marshes, observes Jim Bissell, curator of botany and director of conservation at Cleveland Museum of Natural History.
“Most native plants seem to decline quickly along salted roadsides and sidewalks,” says Bissell. “Based upon my observation at Mentor Marsh, there are some attractive native plants that apparently tolerate salt quite well. Swamp Milkweed and Common Milkweed both seem to survive in association with salt marsh aster along the Wake Robin Board Walk.”
Four years ago a Plain Dealer article observed road salt and future fear of contaminating groundwater.
“Adding a high concentration of chloride from increasing uses of road salt, along with salt from other sources like wastewater treatment plants and farms, is particularly bad for the streams. Eventually it could affect drinking water,” quotes John Mullaney, hydrologist with the U.S. Geological Survey.
Native plants that used to be present on Ohio’s roadsides once resembled disturbed prairie of Black-eyed Susan, Blackberry, Blue False Indigo, Common Milkweed (some salt tolerant), Coreopsis, White and Purple Prairie Clovers, Lupine, Ironweed, Nodding Wild Onion, Passionflower, Poison Ivy, Pokeweed, and Sassafras. With salt runoff it adds another level of disturbance in an already disturbed ecosystem, soil salinity concentrates.
“Many emergent marsh species, especially rushes (Juncus sp.) survive well along salted roadsides Juncus brachycarpus, formerly rare in northeastern Ohio, is now common adjacent to the Black Brook Salt Fill,” says Bissell. “Many salt marsh plants from the eastern Atlantic Coast now thrive on our roadsides.”
Native plants that once thrived in disturbed habitats like construction areas and roadways are dying off from salty brine runoff, reducing diversity to non-native monoculture like black grass that out-competes native food sources for pollinators. In 2004 a total of 550 million Monarchs completed their annual migration to Mexico. In 2013 a total of 33 million Monarchs completed the annual migration to Mexico. While some believe farms spray too much for Milkweed (their vital food source, which has seen a 21 percent drop during this same period). Soil ecosystem salinity is more prevalent and may be affecting organic food production from other pollinator insects that have less food availability.
Monarch butterfly great-grandchildren make the next migration back north.
Neil Diboll, president of Prairie Nursery and recent native seed partner of Groundz, observed that food production depends on healthy ecosystems and the important role of pollinator insects.
“Native plant gardeners have long known how important bees, butterflies, moths, hummingbirds, and even wasps, flies and ants are for maintaining diverse food webs,” writes Diboll in Prairie Nursery 2015 Native Plant Catalog and Growing Guide. “Native trees, shrubs, and flowers support a plethora of pollinators that are essential to the production of flowers, fruits, berries, nuts, and other foods upon which people and wildlife depend.” Many of Prairie Nursery’s native plant seeds are suitable for disturbed areas like the urban landscape, but with salty brine rinsing into the soil severely restricts native plants that can grow there.
Diboll mentioned that a Prairie Nursery customer is experimenting with growing native plants in salty soils.
“I have a customer who is experimenting with salt tolerance of prairie plants by planting them along her roadside that receives significant road salt in the winter,” said Diboll. “Hopefully she will have results in the next couple of years.”
Transportation departments, city services, and salting companies should return to how roads were once salted prior to 1950s when winter roads were treated with mostly sand mix; at least if soils become sandier water drains rapidly to favor many beneficial native plants.
Prairie Onion, Bearberry, Whorled Milkweed, Big Bluestem, rye grasses, Butterfly Milkweed, Sky Blue Aster, Heath Aster, Prairie Sagewort, Smooth Aster, Lanceleaf Coreopsis, Stiff Coreopsis, Purple Poppy Mallow, Harebell, Wild Strawberry, Prairie Smoke, Scaly Blazingstar, Ohio Spiderwort, Wild Petunia, Hoary Vervain, and Dotted Mint could be dotting miles of Interstate ecosystem that could provide diverse pollinator’s food for food production.
“Seaside goldenrod (Solidago sempervirens) is now fairly abundant along Interstate 90 in Lake County,” says Bissell. “It is among the most attractive native goldenrods. It blooms well into early winter and the red color of its fall/winter foliage is quite beautiful.”
More research is needed to determine if seaside goldenrod and scratch grass may uptake salt from the soil to determine if planting such a species could be bioremediation for salty soils. Legumes like beans, root crops like beets, and fruit like tomatoes may grow in salty soils, but most likely if salt concentrates are greater than 7 percent tomatoes and beets may not survive (milkweeds may not survive either). Research is also needed to learn salt tolerance of beans, legumes, and other cover crops. Most importantly is keeping your winter surfaces safe require intentional planning: Consider creating your own salting/traction mix using as little salt as possible, a sand/grinded corn husk/coconut coir/coffee grounds/pistachio nut shells organic mix. Coffee grounds and coconut coir are absorbent, naturally reducing water and ice.
Cleveland Chef Jonathan Sawyer’s culinary team recently made with grapefruit, tomato, fish head, chanterelle and lobster roe infused salt.
After we finish salting our driveway with iodized salt; in late spring we may sprinkle some of Chef Sawyer’s salt mix on soil surrounding our freshly planted vegetables.
When Bissell was asked what he would grow in salted roadside soils: “I have a hunch scratch grass (Muhlenbergia asperifolia) may be a good plant to remediate soils. I assume continuous harvest and disposal during the growing season would be a good method for removing salt from soils. My preference would be to plant and harvest seaside goldenrod because it is so attractive.”