Cape May County supplies the grass that keeps the East Coast's sand dunes standing during storms
MIDDLE TOWNSHIP — Hurricane Sandy was not long gone when the phone started ringing at what could be called the birthplace of the modern, fully vegetated sand dune.
Sandy ravaged the South Jersey coast, but it quickly became evident that towns with the best sand dunes suffered the least damage. The U.S. Department of Agriculture’s Cape May Plant Materials Center in the Swainton section of Middle Township, Cape May County, had much to do with that. Now, towns are planning restoration of their dune systems.
“We’ve already gotten orders for 150,000 beach grass stems. The demand will be huge this year,” said center manager Chris Miller.
The center, which serves nine states from North Carolina to Massachusetts, was created after the 1962 March Storm damaged the Northeast coast. Its mandate was to test and develop plants for shoreline restoration and to make them available to the public through the commercial nursery industry.
Dunes are of varying certain size, height and slope, but they also use a diverse mix of vegetation to trap sand and serve wildlife. Vegetated dunes suffer less erosion in storms and do a better job holding back the water because the network of roots holds them together. Such dunes also rebuild quicker after a storm.
Cape American beach grass was the first plant the center developed on an 88-acre tract of land here off Route 9. It began working on the plant, using a variety that grew on Cape Cod, Mass., shortly after opening in 1965 and released it to commercial nursery operations in 1972. It grew faster, had a higher survival rate, superior sand trapping ability and the thickest stems of any beach grass tested. There are now 16 companies growing it from stems provided by the center, said Miller. Growers take the stem and cultivate it to produce more stems.
“Each stem we give a grower produces on average 25 to 30 stems a year. In a bad year it’s 15 stems. This year it was 60 from each individual stem because it was a real good growing year,” said Miller.
But the science of a sand dune has come a long way in the last 50 years. Towns used to just plant beach grass and wondered why the monoculture often had problems surviving. Beach grass needs a constant supply of new sand that brings in nutrients; it would often thrive on the front of the dune facing the ocean but suffer on the back side. A natural maritime forest features several ridges of sand parallel to the ocean with different vegetation in each section.
Over the years the center has developed 16 other plants for sand dunes, Miller said. Some are grasses and wildflowers that thrive on the back side of the primary or first-line dune. Others are woody plants such as the Ocean View beach plum and the Wildwood bayberry, whch may go on a secondary dune farther from the ocean. Natural sand dunes often have trees growing behind them, but the center produces woody plants that are low-lying to preserve ocean views for property owners.
Some plants are designed to fortify the dune but also to serve wildlife, such as the Monarch germplasm, a seaside goldenrod the center developed because it feeds migrating monarch butterflies. Plant diversity attracts birds and other wildlife and that actually helps reseed plants and increase dune vegetation.
Diversity also helps prevent disaster, said Cape May Point Administrator Connie Mahon, whose town has peppered its dunes with a wide variety of plants including seaside goldenrod, coastal panicgrass and others, but not beach plums, because then people would walk on the dunes to pick them.
“If dune grass gets a blight and gets wiped out, you’re left with nothing,” Mahon said.
Feeling its oats
The center’s latest experiment, not yet ready for distribution, is with a plant called sea oats. It doesn’t normally survive north of Virginia Beach but the center has been using the Avalon dunes since 1993 to grow sea oats, with new plants being grown from the seeds of ones that survive the winter.
Miller said the center is “getting close” to producing a plant that is genetically adapted to winters north of Virginia. The goal is one that can survive in Maryland, Delaware and New Jersey.
“It’s just another tool in the plant tool box. People like the look of sea oats. It’s vigorous and takes over. Beach grass loses energy and vigor without accumulating sand but sea oats doesn’t require that. It can go in the frontal dune and survives in back of the dune,” Miller said.
The center is also working toward a future when a shore town can seed its own dunes with the perfect mixture of dune plants. Most towns use full-sized plants and plant them individually, often using volunteers. The future could be seeding a dune like a farmer seeds a field.
“In the future we’ll work more on a mix of species you can successfully seed in a dune. We feel we can get more diversity, quicker and more economically, by developing a seed mix that is successful,” Miller said.
Dune builders have begun using seeds instead of full plants. The center provides Atlantic panicgrass seeds that have been successfully sowed between rows of beach grass.
Avalon is known for its dune system and Mayor Martin Pagliughi said it’s no accident. He said the borough uses the dunes as the first line of defense to protect $8.4 billion in ratables. The dunes help lower flood insurance rates for homeowners and last summer were a factor in Moody’s increasing the borough’s bond rating to Triple A, which the mayor said will save $250,000 a year in debt service.
Dunes, Pagliughi argues, pay for themselves.
Avalon has a Dune Vegetative Management Plan and for years has hired a crop-dusting biplane to drop fertilizer on the dunes. Pagliughi remembers the October fertilization after the Sept. 11, 2001, terrorist attacks.
“We got about 100 phone calls when people saw the plane coming down the beach,” Pagliughi said.
Avalon follows a Federal Emergency Management Agency template on what a dune should be. This covers things such as the height, width and slope, the pattern for the snow fencing, the vegetation, and the distance to the high water line. Having an engineered beach following FEMA guidelines can also lead to federal funding to rebuild after a storm.
“My advice is if you’re going to rebuild dunes after Sandy follow the FEMA template. The proof is in the pudding. The towns that had dunes built to the FEMA template were the towns that survived,” Pagliughi said.
He also advises using a zigzag pattern with the snow fencing and putting walkways on an angle to the frontal dune to keep surging water from coming through them.
Even Avalon has made some mistakes over the years but has learned from them. For years the town planted Japanese black pines in the dunes but now they are seen as an invasive species, a fire hazard and a monoculture.
Pagliughi said Avalon lost one-third of its frontal dune during Sandy but will rebuild it this winter and replant it in March.
Dave Church, of Church’s Seashore Nursery in Lower Township, has been selling dune grass for almost half a century, growing about two million plants a year, and he stresses regular dune maintenance. This includes filling in bare spots regularly and fertilizing the top and back of dunes that don’t get a regular dose of new sand.
“We’re farmers and farmers have to fertilize. You have to feed them a lot, and people won’t listen,” said Church.
Church’s, a nursery here since 1889, ships bundles of 100 two-stem planting units from the Carolinas to Maine and even to the Great Lakes region. Buyers are towns and private homeowners. Church recommends planting two stems in each hole, 12-18 inches apart in staggered rows. The planting season is Oct. 1 to April 15 for bare-root plants and year round for container-grown plants.
“The beach grass is the best for stabilization. Bayberry is very good. Rugosa rose is very good because the thorns keep people off the dunes,” Church said.
Ocean City is one of a growing number of shore towns that does regular dune plantings, mostly dune grass in the frontal dune and beach plums or rugosa rose in the backside. The plantings draw hundreds of volunteers and the city’s Environmental Commission uses grants to put up signs and educate the public on the importance of dunes.
Peter Ault, chair of the commission, said beach replenishment sand costs a lot of money but a vegetated dune helps that sand last longer.
“Our job is to do the best to maintain what we get. The cost of replenishment goes down if you maintain a well-vegetated dune system. You need to put less sand in place and you do it less frequently,” Ault said.
Water from Sandy did not breach the city’s best dunes in the center of the island but there was flooding in the north and south end where the dunes are not as wide, Ault said, adding that Avalon had “nowhere near the damage” as Ocean City because of its wide dune system.
Ault also stressed filling in bare spots and getting plants on new dunes as soon as possible after replenishment, dune grass first and then woody plants.
“All these things take time to grow into place. It takes time and you need a little luck,” Ault said.
Contact Richard Degener: