AH-CHOO!
A Dark Cloud Hovers
The end of May and early June is such a glorious time of year in the garden, with plants thoroughly leafed out yet still showing the exuberance of spring growth. (Those of you to the north of me, Zone 5 in New York’s Hudson Valley: your time will come. Y’all to the south: enjoy your camellias, southern magnolias, muscadine grapes, figs, and . . . all the plants I wish I could grow this far north.)
Yet even on the clearest, sunny day — and especially on that kind of day — a dark cloud hangs overhead. Hay fever, literally from hay that is, grasses; and nonliterally, from tree pollen.
Every year the small white blossoms opening on multiflora roses signal that a sneeze season is on. That’s why this late spring allergy season is sometimes called “rose fever.” Rose is not the culprit; is just an easy to note phenological indicator of the progress of the season. Each plant awakens and starts its growth cycle in spring in response to a set accumulation of warm weather. Multiflora rose sends out a signal that the culprits are at work.
Multiflora rose puts on its show to attract pollinators, such as bees, which transfer pollen from one plant to the next. Hay fever is from airborne pollen blown about by wind, so the flowers of these allergen plants have no need to attract insect pollinators. The non-showy culprits this time of year are grasses and oaks.
As with many other plant-related events, climate change is also leaving its mark on allergy seasons. Here in the northeast, the effect has been for the season to start earlier with a more intense peak. You would think that my multiflora rose indicator plants would keep apace with climate changes but my records, dating back for decades, indicates otherwise. (Daylength, which doesn’t change from year to year, is also sometimes a driver of plant or animal development through the season, and it can interact with temperature.)
No matter: I didn’t have to see a blooming multiflora rose the other day to know that my hay fever season was in full swing.
And the Culprits Are . . .
To at least make this allergy season more interesting, I thought I would look more closely at nearby flora and try to identify the specific culprit or culprits.
I can start by looking no further than the grassy meadow which comes to an abrupt stop at the close shorn lawn only about fifty feet to the south of my home.
With their small, nonshowy flowers, grass species are generally not easily identified. But I can narrow the field, figuratively, by species that are common in the Northeast and that I see now blooming in the meadow. The lineup, then, includes Kentucky bluegrass (Poa pratensis), sweet vernal grass (Anthoxanthum odoratum), and orchard grass (Dactylis glomerata).
Kentucky bluegrass
Sweet vernal grass
Orchard grass
According to the 1937 USDA Yearbook of Agriculture, most grasses bloom “most abundantly in early morning,” with a secondary flowering period for many of them in the afternoon. The bloom period might be delayed and prolonged in cloudy weather.
Although rain washes pollen out of the air, thunderstorms are another story. Thunderstorms are usually accompanied by winds, which lifts and blows pollen about, and the electrical charges induced by lightning throw add yet another layer of discomfort to the mix.
I just went out to the meadow to jiggle some seedheads of the culpable grasses. The pollen is heavy enough to travel only a few feet, even in a breeze.
Tree pollen is lighter than grass pollen and launches from greater heights. So I’m adding oak to the lineup. The two oaks most common around here are red oak (Quercus rubra) and pin oak (Q. palustris), with red oak, because of its bloom time being most culpable.
So there you have it: 3 grasses and an oak. They’re all nice plants, attractive and decorative. And, in the case of sweet vernal grass, also fragrant. If only they . . . or if only I . . .
I have my eye out for the flowering of catalpa trees and mountain laurel shrubs this time of year. Flowering of either of these plants are a signal that that relief is in sight that my hay fever season is over for the year. Again, these plants aren’t spilling any magical anti-hay fever concoctions into the air; they are merely phenological indicators of what’s happening with other, less conspicuous, flora and fauna.
Plaintain, not a sneeze-inducer
DRIP WORKSHOP
See www.leereich.com/workshops for information about the upcoming drip irrigation workshop on June 30th.
A Changing Landscape
Wormy Matters
Charles Darwin did some of his best work lying on his belly in a grassy meadow. Not daydreaming, but closely observing the lives and work of earthworms. All this lying about eventually lead to the publication of his final book, The Formation of Vegetable Mould through the Action of Worms. Darwin calculated that earthworms brought 18 tons of nutrient-rich castings to the surface per acre per year, in so doing tilling and aerating the soil while rendering the nutrients more accessible for plant use.
I wouldn’t find that many earthworms at work in my own grassy meadow. The last glacier, which receded about 12,000 years ago from the northern parts of the U.S., including here in the Hudson Valley, wiped out all the earthworms. Darwin’s meadow was spared because glaciation didn’t reach as far south as where Darwin’s home eventually stood.
Not that there aren’t now any earthworms here. Mostly, these are non-native species that arrived over the past couple of hundred years and continue to arrive as fishing bait, ship ballast, and in soil clinging to the roots of transported plants. Some native earthworms may also have made it up here from New Jersey. Not many, though, with their estimated top travel speed of less than 6 yards per year.
These non-native earthworms are of concern because of the rapidity with which they gobble up organic matter. Their voracious appetites threaten the mountain laurels, rhododendrons, and blueberries that thrive in the organic matter — the leafy mulch — that blankets the forest floors in our nearby Catskill and Shawangunk Mountains.
Those invasive species could effect a change in the landscape we view as we drive along mountain roads and hike the trails.
Grassy Matters
Back to my meadow, which I have also spent a lot of time observing, but from a standing position, usually with a scythe.
Most years the meadow receives a once a year mowing, usually in late autumn, with a tractor. (Early on, I mowed it all summer long with a scythe but the rich soil encouraged lush growth that resulted in tennis elbow. I still scythe parts of the meadow, in moderation.) That once a year mowing is meant to forestall the encroachment of woody plants. In this part of the world, open land typically reverts to forest.
At its best, my meadow presents a lush sea of green that contrasts nicely with the close-cropped areas of lawn near my home. A sinuous path mowed through the meadow, tracing out a different route each season, invites walking through it for more intimate exploration. (I refer to this as “Lawn Nouveau” in the grass mowing chapter of my book, The Pruning Book.)
Through summer, pale pink milkweed blossoms dot the meadow. Come late summer, purple flowers of bee balm cap the sea of green grass like ocean whitecaps. And then, later and on into autumn, various species of yellow goldenrod bloom in succession. In the cool of the morning, dew and morning sunlight bring sparkle to the show.
Grasses Return
A couple of seasons ago I noticed that bee balm and goldenrod were getting increasingly sparse, as were the grasses. Each year increasing amounts of multiflora rose, wild blackberries, poison ivy, even an occasional staghorn sumac were honing in, paving the way to a forest.
Last summer I decided to tip the balance back to meadow. My plan was simple; all I did was mow the field regularly to lawn height. Grasses, which are monocotyledonous plants with their growing point just below ground height, are pretty much the only plants that tolerate regular mowing (or, in the case of prairies, burning). Mow, and grass will come.
This year, meadow grasses are already growing thickly and a couple of feet high. Looking closely, I see very little poison ivy and friends. I will be interested whether or not bee balm and goldenrod appear onstage later, in summer. Another season or two may be needed before they make their appearance.
Inevitable Changes
Our forest flora are dynamic. The nearby mountain laurels, rhododendrons, and blueberries, meadows, all landscapes, in fact, are not forever, even without human encroachment. I’m not trying to maintain my meadow in a romanticized primordial state; I just like the look of the grasses, bee balm, and goldenrods.
The meadow also has a practical side. My scything provides hay for compost (along with some horse manure, a waste product of a local stable) and mulch. Taking the hay from limited and different areas each season allows time for the soil to regenerate itself.
