West and Southwest

High temperatures and low rainfall were experienced in most of the West and Southwest. Linda Thornton of Tucumcari, New Mexico, noticed drought-stress symptoms on trees and shrubs throughout New Mexico, even on the resilient cottonwoods.

"Where I garden, in eastern New Mexico, the earth is turning to dust except in the places where I water," says Thornton. "Usually I have to mow three to four times a year. I have a mix of drought-resistant grasses-Bermuda, Muhly (Muehlenbergia spp.), buffalo-this year I didn't get out the lawn mower once-just used the string trimmer where I water the trees and shrubs."

Thornton observed that the usually thriving grasshopper population was nearly non-existent this year, "I suspect the animals that depend on insects are going to have a tough time. Same for the seed-eaters, since this has been the worst year for wildflowers I've ever seen."

Pacific Northwest

Extension agent Mary Robson of King County, Washington, notes that her region has experienced several odd seasons in the past 15 years, primarily with respect to precipitation. They experienced record snowfall-21 inches-in 1996, and near record amounts of rainfall in 1997. In contrast, Robson explains, "During the winter of 1999-2000, we had fewer than 6 days of freezing temperatures, more clear days than normal, and no snow at all."

This past summer was a dry one in western Washington. "We had less than an inch of rain each month in July, August, and September, leaving gardens very dry indeed," comments Robson. "But that's normal for the modified Mediterranean climate we have." Though many people think of the Seattle area as being subject to constant rain, "what's more common," explains Robson, "is that we have a lot of cloud cover even on dry days."

The mild temperatures of recent years may be building a false confidence in local gardeners with respect to the range of plants that they can grow. Robson says, "People are under the belief that a lot of marginally hardy plants are actually thriving here because their survival hasn't been tested in the last four winters."

South Central

Tim D. Davis, resident director and professor at Texas Agricultural Experiment Station in Dallas, Texas, reports that this season will be remembered as brutally hot and dry in Texas, even though it started out very mild. June in the Dallas-Fort Worth area was one of the coolest and wettest on record. But in July, the weather abruptly turned hotter and drier than normal. "We experienced around 45 days of 100 degree-plus high temperatures. The normal number of days at 100 degrees or above is about 15."

Davis observes that only the very toughest plants such as firebush (Hamelia patens) and goldstar esperanza (Tecoma stans 'Goldstar'), were able to handle the stress and remain in good shape. Even relatively drought-tolerant plants such as live oaks (Quercus spp.) have suffered.

"But in Texas," comments Davis, "we also have to remember that abnormal weather is not that uncommon. It seems like we are always setting some sort of weather record in Texas!"

Rocky Mountains

Temperatures were also higher in the Rocky Mountains this season. "We have had about 20 years of cold, wet summers here. This summer seemed really hot and dry," says Jim Knopf, a landscape architect in Boulder, Colorado. While records suggest that this summer was only a little warmer than usual, it was much warmer than many recent summers.

"The effect on plants has been remarkable," reports Knopf. "For example, people have had real difficulty with tomatoes for years; this summer was much better. My buffalograss loved the warmer afternoons." Knopf observes that desert plants that need hot summers to bloom, such as California fuchsia (Zauschneria spp.) and Zinnia grandiflora, performed much better in 2000 than in the preceding years that experienced cooler summers.

But not all plants thrived in the heat. "Pansies usually bloomed all summer in the recent 'Alaskan summers' in my yard-not this year. They fried."

Northeast

Cooler summer temperatures were reported in much of the Northeast. In parts of Maine, this combined with an outbreak of late blight with the result that tomatoes were not able to ripen before frost killed the plants, reports Dave Fuller of the University of Maine Cooperative Extension Service. Fuller observes that lawns thrived this season. "The lawns of the western foothills did not go dormant as they often do, so we had to keep up a regular mowing schedule."

Cranberry grower Charles Armstrong explains that cranberries needed little irrigation this year but, "disease pressure was higher due to the moisture." He experienced more red leaf spot on his plots and notes that other growers experienced above-average levels of fruit rot.

"Some crops responded nicely to the change, others did poorly," says Extension educator Marjorie Hundhammer of Hancock County, Maine. While gardeners needed to do very little supplemental watering, several insect pests including squash bugs were prevalent. "Cucurbits [squash, melons, gourds] seemed to perform the most poorly this year," comments Hundhammer. "Cool-season crops, on the other hand, such as broccoli and peas did quite well."

Mid-Atlantic

Much of the central East Coast, which experienced drought in recent years, enjoyed a much cooler, wetter growing season in 2000. Michael Newell, horticultural crops manager at the University of Maryland's Wye Research and Education Center, says, "This year was a 180-degree turn from last season, although in early spring it started out warmer and drier than it finally turned out." For perennial fruit crops such as apples, this resulted in an extended harvest season in contrast to last year's very concentrated harvest period.

Newell reports that asparagus quality was better, with "not as much lost to over-maturity." But tomatoes, corn, and watermelon planted for early harvest were slower to mature. And diseases were more troublesome than usual, particularly those that are soil borne. Newell notes, "This seems to have been a year where if you have been using crop rotations to manage your farm or garden, it paid off."

At River Farm, the American Horticultural Society headquarters in Alexandria, Virginia, director of horticulture Janet Walker also observed a marked increase in the incidence of disease. Additionally, lawn areas required more mowing than usual because the turf grass never went dormant.

Southeast

But further south, drought conditions prevailed. Raymond Zerba, agricultural extension agent in Clay County, Florida, explains that northeast Florida has experienced three consecutive years of unseasonable droughts that start after spring green-up in April or May and persist into September. Though many gardeners provide supplemental water to their gardens, Zerba observes that this is often insufficient. The stress that results, especially with trees, makes them more susceptible to damage from insects and disease. "As a result, we see them just suddenly up and die. That's been happening a lot this year among some of our large shade trees," Zerba says. "This extended drought seems now to be taking a toll."

North Central

Sandy Mason, horticultural extension educator in Champaign, Illinois, explains that this year has been either wet or dry, depending on where in Illinois you are standing. "Just north of us they are much drier," she says, "and to the south they are practically swimming." While last August was cooler than usual, recent winters have been warmer. This is likely the reason for this season's high numbers of certain insect pests such as Japanese beetles.

Milder winters have also meant certain marginally hardy plants have survived. But Mason notes that in general, "plants that were well sited and selected are doing fine to great; those on the edge where we have made poor choices or conducted poor management practices are suffering." She observes that this reinforces the importance of good basic plant care, and that "in this ball game, Mother Nature bats last."

Rita Pelczar is associate editor of The American Gardener.

Earlier Flowering Dates Observed

The famous Japanese flowering cherries that line the Tidal Basin in Washington, D.C., are blooming about a week earlier than they did 30 years ago. Researchers from the Smithsonian Institution's Department of Botany recently released the results of a 30-year study that tracked the flowering dates of 100 species of plants common to the Washington, D.C., metropolitan area.

Oriental cherries (Prunus serrulata) and Yoshino cherries (P. yedoensis) reach their peak blooms six and seven days earlier, respectively, than they did at the beginning of the study. And cherries were not the only plants with earlier flowering dates; 89 of the 100 species studied displayed a continuing trend of earlier flowering each year. The average flowering date for plants studied was 4.5 days earlier in 2000 than in 1970.

Botanist Stanwyn Shetler of the Smithsonian's National Museum of Natural History, one of the authors of the study, explains that the consistently earlier flowering of the vast majority of species studied indicates that the growing season of this region is gradually expanding. If the trend continues, it will likely have an impact on the composition of local flora: Those plants that require a long cold season may die out, while invasive species from warmer regions may become more serious problems.

Similar studies are being conducted in other regions. The University of Alberta's Devonian Botanic Garden has been gathering data on flowering times along with other discernable changes in life cycles for eight common plant species, including common lilac (Syringa vulgaris) and serviceberry (Amelanchier alnifolia). Using computers to collect information from volunteers, this program, called Plantwatch, is gathering data from locations across Canada, parts of the United States, several European countries, and Japan. If you are interested in learning more about this program or becoming a Plantwatch volunteer, visit its homepage: www.devonian.ualberta.ca/pwatch.

Resources

• Heat-Zone Gardening: How to Choose Plants That Thrive in Your Region's Warmest Weather by H. Marc Cathey with Linda Bellamy. Time-Life Books, Alexandria, Virginia, 1998.

• Sunbelt Gardening: Success in Hot-Weather Climates by Tom Peace. Fulcrum Publishing, Golden, Colorado, 2000.

• The Undaunted Garden : Planting for Weather-Resilient Beauty by Lauren Springer. Fulcrum Publishing, Golden, Colorado, 2000.

• Weather in the Garden by Jane Taylor. Trafalgar Square Publishing, North Pomfret, Vermont, 1998.

• Climate Prediction Center - www.cpc.noaa.gov/

• National Climatic Data Center - www.ncdc.noaa.gov

• Regional Climate Centers - www.ncdc.noaa.gov/regionalclimatecenters.html/

• Spatial Climate Analysis Service (Climate maps of the U.S. Many of them downloadable for free.) - www.ocs.orst.edu/prism/prism_new.html/

• State Climate Offices - www.ncdc.noaa.gov/stateclimatologists.html/

• USDA National Arboretum Plant Hardiness Zone Map - http://www.ars-grin.gov/ars/Beltsville/na/hardzone/ushzmap.html