CLIMATE CHANGE
Gordon and Mary Hayward’s Garden Westminster, Vermont- Zone5
Frost damage May 17 on Fagus sylvatica ‘Riversii’ hedge
It appears to Mary and me that climate change is beginning to impact our garden in new ways. Since 1984, when we began gardening here, we have seen a warming climate allow us to expand our range of plants from a clear Zone 4 into Zone 5. Over the past ten years of so, we have seen a gradual extension of the gardening season from late October into mid and later November. In one sense, that has been a good thing, but it does point to change toward a warmer winter. We have also seen much less snow and therefore much less snow-cover on the garden. The snow therefore melts much more quickly, exposing the ground to more and more weather changes. As the climate warms, other changes have begun to appear. One of those changes is that the timing and nature of Spring has become largely unpredictable.
Magnolia ‘Elizabeth’
In mid-April this Spring we experienced unheard-of temperatures in the low 90’s and blazing sun for three days. Those temperatures caused dramatic growth of flower and leaf buds. Four or five days of southerly winds with temperature in the low nineties, we experienced cloudless skies and blazing sunlight. Garden soil dried out; young plants recently planted wilted. Those blistering days were instantly followed by winds and breezes directly out of the north causing daily temperatures to drop in a day into the fifties and low sixties and remained so for at least a week with virtually no rain for two-three weeks.
Acer palmatum ‘Twombly’s ‘Red Sentinel’ May 17
Then on May 17, everything changed. While we have for years expected a light frost anytime in May, on the 17th, overnight temperatures dropped deep into the 20’s, a deeper frost than anyone can remember. Those temperatures devastated the unusually advanced leaf and flower buds in perennials, shrubs and trees throughout the garden – an advancement caused by the temperatures in the low nineties three weeks or so earlier. Even now, June 12, our Twombley’s Red Sentinel Japanese Maple is struggling to put out leaves. A naturally occurring Beech tree in the garden appears unable to replace the leaves in the upper half of that 20’ high tree. Some eight or so varieties of Magnolias have lost all flower buds and even today, nearly a month after the frost, have only been able to begin releafing while brown, dead leaves and flower buds dangle from the branches. Aralia spinosa has releafed, as have fastigiate Pin Oaks, albeit very slowly. Perennials have rebounded just fine.(A note from June 24: All woody plants except a young Styrax obassia are slowly releafing.)
One key bellweather is frost damage in the apple orchards of Vermont and across the whole of the Northeast. Green Mountain Orchards, just a mile or two from our garden, in nearby Putney, VT, lost 75% of their apple blossoms across 90 acres. The remaining 25% were severely damaged and will produce only apples for pies. The State of Vermont estimates losses to apple farmers will total at least ten-million dollars. (My brother Peter, at our family’s orchard in NW Connecticut, lost his entire peach crop to temperatures below minus 10 degrees.)
Wildfires in southeastern Canada in early June raged and smoke and strange hazes floated across our fields and garden. Neighbors have reported eerily pink/orange sunrises never seen before. We drove through Upstate NY on Interstate 90 on the 8th of June, sometimes driving through a thick haze of smoke that blanketed vast areas of the landscape.
These weather anomalies were all preceded by an unusual Autumn, 2022 and winter, 2023.
Summer, Fall 2022
The first rabbits we have ever seen in the garden appeared.
Unusually severe winds directly out of the west blew often and powerfully on and off for weeks. The winds were unusually cold and strong, resulting in broken branches, both alive and dead, littering the gardens and lawn. Never have I picked up so many sticks and branches.
Winter, 2023
On March 15, 2023, an extremely heavy, dense snow fell for hours, accumulating some 24” of snow on the ground and weighing down leafless branches. I did my best to knock off the snow but had to cut down two thirty-year old birch trees (Betula populifolia ‘Whitespire’) that were beyond repair. Broken branches on other tree were everywhere.
When the snow melted completely weeks later, I spent days cleaning up after the damage. Never had we seen such snow damage in the nearly 40 years we have been gardening here.
Even now, in May, we see dead branches caught up, unreachable by any other than an arborist, in the canopies of mature 150-200 year old maples, cherries, honeylocusts.
Ticks, Deer, Woodchucks
TICKS have been the worst in years. A friend who manages a 1,000 acre property of 100 acre fields and woodland, a man who knows the natural world like no other I know, tells me this is the worst year for ticks he has ever seen: “I’d rather wrestle a 200 pound Black Bear to the ground than have to deal with a tick bite.” One doe he found in a field was dying from huge numbers of ticks on it.
DEER: Two or three times a year I scatter Milorganite, a garden fertilizer made from human waste, around the entire perimeter of our 1 ½ acre garden. Because our garden is surrounded by a few hundred acres of hay meadow and land for grazing sheep, we have no woods adjacent to the garden. We see virtually no deer in the garden except perhaps in the winter. After deer decimated our yew and Arbor vitae hedges about ten years ago, we securely cover all those hedges with a stiff, 1” open mesh, black deer fencing. It has worked, but it takes us just under two days to install in late November and take down in late April.
MOSQUITOES: Four or five, even six pairs of Barn Swallows nest in our barn (as they have for decades, long before we bought this place in 1983) and they spend all day every day from early May until they leave in late September feeding on mosquitoes in the air. Their two broods of four or five young every summer are fed largely on mosquitoes their parents snatch out of the air while flying.
WOODCHUCKS: Each year we have been troubled by one or two woodchucks. In late May into June they eat the tops of young growth on perennials, including flower buds. We trap them with Havahart traps and take them to distant wooded areas.
Plants damaged by frost on May 17, 2023
A strong late frost struck the garden, with temperatures in the 20’s, seriously damaging new foliage on flowering shrubs and trees that were not sheltered by overhanging tree branches, and in some cases, even many that were covered by same. The damage was widespread in both native and introduced trees and shrubs. I’m writing this June 6 on a day when it’s in the low 60’s with heavy winds from the north. (My brother Peter in New Hartford, Connecticut lost his entire peach crop from a January or February night of minus 10-12 degree temperatures. His apple crop survived.)
NATIVE TREES
Quercus palustris – Pin Oaks, both four fastigiate as well as 35 year old mature trees – leaves singed
Robinia pseudoacacia – Honeylocust
Fagus grandiflora – Beech - the top half of a 20’ tree is leafless as of 6/12/23
Ginko biloba
INTRODUCED TREES
Acer palmatum ‘Twombley’s Red Sentinel’ – new leaves killed – I removed all by hand 6/5. It took a month for the young tree to releaf.
Aralia spinosa – new leaves emerging succesfully
Catalpa bignonioides (pollarded) new leaves very slowly emerging June 6
Cercidiphyllum japonica – Katsuratree – severely damaged -loss of all leaves and very slow to recover
Cladrastis kentuckea – Yellowwood – severely damaged leaves and flowers – very slow to releaf
Fagus grandiflora – American Beech hedge – damaged surface leaves but shorn off by me June 4
Fagus sylvatica ‘Purpurea’ – Planted 1998 in the form of 5’ plants grown in Ohio from seed to increase hardiness; We’ve never had a single singed leaf until May 17, 2023. Leaves singed on exposed tips along north side of hedge; south side OK as leaves are under overhead Maple branches. Top of tunnel severely damaged as far as a foot down the upright stems
Ginkgo biloba – two varieties – seriously damaged leaves – very slow to releaf
Gleditsia triacanthos – Yellow Leaved Honeylocust - denuded
Maackia amurense – very slow to releaf but thinly releafed by June 7
Magnolia ‘Elizabeth’ – flower buds and leaves killed, very slowly releafing as of June 6
Magnolia ‘May to September’ – flower buds and leaves killed; slowly releafing
Magnolias - 3 Stefan Cover hybrids – leaves and flower buds singed
Styrax obassia – leaf buds have not even formed let alone unfurled as of 6/12
Morus rubra – Mulberry (Weeping form) – denuded and very slow to releaf
Phellodendron amurense – Cork Tree – deleafed and very slow to recover – as of June 7, only partially releafed. A good deal of dead smaller branches.
SHRUBS
Buxus koreana – The foliage on the flat tops of hedges in the Herb Garden are singed and unsightly but will be largely removed when I trim hedges in a few weeks.
Buxus sempervirens – both exterior and some inner leaves were singed even under cover of deciduous trees. We have never seen this before.
Ilex glabra – Winterberry – leaves stunted and slow to develop
Cotinus coggygria – Purple-leaved Smokebush – leaves scorched
Clethra alnifolia – virtually denuded, severely damaged and struggling to releaf – the most damaged of all plants
Clethra alnifolia ‘Sixteen Candles’ – leaves singed but not nearly as damaged as the species
Cercidiphyllum japonicum – yellow-leaved form - top leaves severely singed.
Taxus media ‘Hicksii’ hedges unharmed
Hypericum ‘Hidcote’ – 9 killed in the winter of 2022, two others finished off by the winter of 2023
VINES
Schizophragma hydrangiodes – denuded – leaves just emerging 6/6
Hydrangea petiolaris – all blooms killed – leaves lightly singed
Actinidia kolomikta leaves singed and very slow to releaf even in early June
Grape vines – all young leaves killed – slowly releafing
Damaged Blooms on tree and shrubs
Lilacs – blooms destroyed
Crab Apples: fruits severely reduced
Donald Wyman
Prairiefire
SugarTyme
Adams
PERENNIALS
Rodgersia pinnata – severely damaged
Astilbes -singed
Mukdenia rosii ‘Crimson Fans’ – severely damaged
Hosta - leaves in many varieties singed, curled and brown
Thalictrum dioicum – Meadow Rue – foliage tips singed