|Salt-damaged white pines along Route 35, near Mantoloking, NJ (April 2013)|
This spring, many homeowners along the coast - if their homes are still intact, that is - find that they have the additional task of disposing of the brittle corpses of trees and shrubs left dead or dying in the wake of Super Storm Sandy.
One Person’s Garden
The second Saturday in April was sunny and warm – one of the few such days this dreary spring. I jumped at the chance to work in the garden, rather than spend another dusty day indoors removing more damaged wall board. I fixed the back fence; untied the Adirondack chair from the deck railing (I didn’t want it to float away again); and moved the wooden bench onto the patio from the back storage shed. It was too chilly to get out the bucket and scrub at the dirty flood line left on the bench. That would have to wait until my next visit.
I spent the rest of the day raking, trimming the ragged ends from my shrubs, and taking a plant inventory. Since I bought the place some ten years ago, I have gradually replaced the pesky Virginia Creeper with other native plant materials that can survive my neglect. I’m not one for mollycoddling, so they have to be able to fend for themselves. I rely on the advice of local garden vendors – Vaughn’s in Marmora, NJ, is a favorite. They’ve been in the area for decades and always seem to know which plants perform best at the shore.
On October 29, Sandy inundated my property with two feet of salty water. I don’t know how long it stayed – perhaps only one tide’s worth, maybe two. In the days immediately following the storm, the plants all looked as green as ever, in spite of the coating of silt on their lower branches. I had to focus my attention cleaning out the flood damaged contents of the house and carting the heavy garbage bags of sodden wallboard to the dumpsters before the dreaded black mold set in. Towards the end of all that, I passed a sign in the window of the local hardware store, offering 40-lb. bags of something that would counteract the salt left in the soil. By then, however, my strength was waning. The garden would just have to wait.
By the end of the month, little remained of my beds except a mass of brown sticks.
|Front shrubs one month after Sandy (December 2012).|
|The honeysuckle one month after flooding |
The garden’s most significant casualties were two vigorous mounds of Hypericum (St. John’s Wort) whose yellow flowers bloomed all summer long. I would be sorry to lose them. They were a prominent, no-work feature of the beds.
|Hypericum (St. John's Wort) and Sedum before Super Storm Sandy (2012).|
On my way downtown, I witnessed the larger toll that Sandy had taken on the landscape. On every street, lawn crews were loading their trucks with piles of dead shrubbery they had excavated from yards around the city. Arborvitae, Euonymus, yews – so well-tended the summer before – now lay along the curb in mahogany-colored clumps as they awaited pickup.
The Extended Coastal Landscape
I left for home by the noon the next day, having cleaned up as much of the property as I could. It being another beautiful day, I decided to take the coastal route north. I detoured off the Garden State Parkway at Exit 80 and followed Route 35 along the coast from Seaside Park north to Point Pleasant. The route took me through the towns of Seaside Heights, Lavallette, Ocean Beach, Mantoloking, and Bay Head – areas that had seen the worst of Sandy’s winds and storm surge.
|Near Mantoloking, NJ, after Sandy (April 2013).|
In a heightened state of garden awareness after my weekend outdoors, I looked beyond the broken houses that remain strewn about where the storm deposited them and focused on the transformed landscape. Five months after Sandy, sand still covers almost everything except the streets. Yards where once green grass, trees, and flowering shrubs dominated are now barren studies in beige and brown. Since this precarious island was over-washed by both the sea the bay, the amount of sand is not a surprise. What did surprise me was that the plant life that had survived the onslaught of the waves was now moribund.
Carefully planted rows of arborvitae – the workhorse of plant screens – stand like rusty sentinels up and down New Jersey’s coastal Route 35.
|Dead arborvitae along Route 35, near Mantoloking, NJ (April 2013).|
|House along Route 35 near Mantoloking, NJ (April 2013).|
What caused this massive die-off? Why did some plants survive and others didn’t? Why is my garden coming back to life, when those farther North are not? Although many of the specimens are reported to be tolerant of acidic soil, the storm clearly overwhelmed their systems.
In November 2012, just weeks after the storm, Charlene H. Costaris, Horticulturist Consultant at the Rutgers Cooperative Extension of Ocean County, published a paper, Coping with Salt Water Flooding, that provides excellent guidance for coastal gardeners. She noted that the salt water pulled the water out of the plant roots. Ultimately, this will cause root damage that will make the plant more vulnerable in future dry spells.
Costaris notes that the longer salt water inundates plants, the worse the damage will be. The best remedy is to irrigate the area with fresh water after the floodwaters recede, a remedy that works better in sandy soils than in clay or loam. Salt destroys soil structure, but sandy soil doesn’t have much structure to begin with.
A week after Sandy, a Nor’easter dumped several inches of snow and rain along the coast. The storm exacerbated the suffering of many, but it also may have saved some of the plant life. Although rain is not the ideal water source for “landscape cleansing,” especially when mixed with the salt spray of a Nor’easter, the salt in the spray may have been less concentrated than that found in the residue of seawater. Thus it may have offered some benefit, albeit imperfect.
The other remedy is gypsum (calcium sulfate, CaSO4), which helps move the salt out of the soil. According to Costaris, the calcium in gypsum replaces the sodium on soil particles. It is the height of irony that all of that soggy gyp-board that I removed from the house and took to the dumpster could have better been put to better use by crunching it up and putting it on the garden.
In areas to be replanted, Costaris recommends tilling in organic material like leaf compost with the gypsum, which will provide additional storage for the salt in the soil.
Finally, she admonishes gardeners not to fertilize (fertilizers have salts), and not to apply garden lime, which affects the acidity level of the soil, which some plants prefer. Gypsum "does not affect acidity of the soil," Costaris notes. (Mmm. Salt and soil acidity are different! Who knew?) She provides other resources to consult that will help gardeners understand how their soils are faring after Sandy.
None of this, of course, will help the white pines, which may have survived inundation, but are very likely dying because their thin needles are so vulnerable salt spray. Super Storm Sandy’s winds did not carry with them enough rain to dilute the salt, so the trees got a heavy dose. For the browning white pines, Sandra Vultaggio of Cornell Cooperative Extension’s Horticultural Diagnostic Lab recommends waiting for a full growing season to see if they come back, especially the more mature specimens. Maybe, given their susceptibility to salt spray, white pines are not the best trees for a barrier island, even if they do like acidic soils. She suggests mixing them in with other types, both conifers and leafy evergreens.
The Short Course in Salt
OK, so this has been a study in a nutshell. But it helped me understand a bit of the chemistry behind why so many trees and shrubs have turned Coastal Brown. I will continue to rely on my local garden supply stores – they sure know their stuff -- and I am now armed with new tools to resuscitate my salty beds. You can bet that I will stop in at the hardware store the next time through and invest in that 40-lb. bag of gypsum.
Appleton, Bonnie, Extension Specialist; Vickie Greene, Graduate Student, Virginia Tech; Aileen Smith, Graduate Student, Hampton Roads AREC, Virginia Tech; Susan French, Virginia Cooperative Extension, Virginia Beach; Brian Kane, Department of Forestry, Virginia Tech; Laurie Fox, Horticulture, Hampton Roads AREC; Adam Downing, Madison VCE; Traci Gilland, Portsmouth VCE. Trees and Shrubs that Tolerate Saline Soils and Salt Spray Drift. Publication No. 430-031. Blacksburg VA: Virginia Cooperative Extension, Virginia Tech, and Virginia State University. 1 May 2009.
Barcel, Ellen. “What’s causing the browning of LI’s white pine?” Times Beacon Record. 28 December 2012.
Beckerman, Janna, Assoc. Professor, Dept. of Botany and Plant Pathology, and B. Rosie Lerner, Extension Consumer Horticulturist, Dept. of Horticulture and Landscape Architecture. Salt Damage in Landscape Plants. Publication No. ID-412- W. Revised. West Lafayette IN: Purdue University Cooperative Extension Service, Purdue Agriculture. April 2009.
Cape Atlantic Conservation District. Native Plants for Wildlife Habitat Improvement in New Jersey’s Coastal Plain Region.
Costaris, Charlene H., Horticulturist Consultant. Coping with Salt Water Flooding. Rutgers New Jersey Agricultural Experiment Station. Toms River NJ: Cooperative Extension of Ocean County. November 2012.
Van Es, Harold, Prof., Dept. of Crop and Soil Sciences, Cornell University. Saltwater Inundation: Implications for Agriculture. Fact Sheet. Ithaca NY: Cornell University Cooperative Extension. November 2012.