I jumped as something buzzed by me, then slowly backed away as I saw a yellow jacket land on my sage. Another hovered in the tomatoes, and I swore. Pesky things. Last year I'd seen a few, but this year, I couldn't get rid of them. I'd seen them around town, too, darting around trash cans, drawn to bright clothing, and in general being a royal nuisance. There were more of them now than before.

Yellow jacket colonies die in the fall, the queens overwinter and revive in the spring. Cold winters make their survival less certain, but winters at lower altitudes are getting warmer, and so are queens' chances of survival. Consequence: more queens, more colonies. Bad news for gardeners. And anyone else who plans to be outside, which is most of the population of the Front Range.

But whether warmer winters are caused by La Nina, the Pacific Decadal Oscillation cycle (PDO), or global warming, the fact remains that a rise in yellow jacket populations may be the least of what gardeners have to face as the climate changes. Shifts in temperature and snowfall affect gardeners strongly, and we need to prepare for them as best we may.

Temperatures affect all of us, but as gardeners we watch it rise and fall with particular interest. La Nina seems to have affected last summer and this winter, making it drier, though not significantly altering temperature. However, there is some evidence that April, May, and July have been warmer than usual the last few years in the high country. And according to research performed at the Rocky Mountain Biological Laboratory (RMBL) in Gothic, the lowest minimum temperatures in winter at that altitude (9500 feet) also seem to display a significant warming trend of about 9 degrees across the past 19 years.

Several other changes have been noted by biologists at the RMBL. One is that snow cover at higher altitudes is starting approximately two weeks earlier than it did twenty-four years ago. If we consider winter as the number of days snow is actually on the ground says RMBL researcher Dr. Inouye, in a recent article, it's getting longer at higher elevations. In addition, the average depth of the snowpack is increasing; 78 more inches of snowfall today than in 1975. However, at lower altitudes there's less snow, it falls less frequently than it used to, and starts later.

These facts, together with the temperature changes, will have obvious effects on all gardeners in this region. For mountain dwellers, winter minimum temperatures may be around 9 degrees warmer on average, but permanent snowcover may start earlier and last longer. The growing season may begin a little later and end a little later, but should generally be the same in length. Thanks to the increased snowpack, you won't lack moisture in the spring, but higher temperatures in April, May and July may mean increased watering schedules. Even with the higher winter temperatures, you may have to increasingly rely on such gardening aids as black plastic to warm up the ground, water walls to shield more delicate plants, and the like. You may have to take more care to shield both germination and harvests against cooler temperatures and possible freezes or snowfall.

For those of us at lower elevations, the growing season may start earlier and last longer, allowing for earlier planting and harvesting, and the possibility of more than one cropping cycle. However, the downside of higher temperatures and lessened snowfall during winter and spring will be an increased need to water gardens, trees, and lawns. The deeper snowpack in the mountains will fill our reservoirs and remove any initial danger to the water supply, but the longer growing season in the foothills and plains will in turn mean greater water use, and Colorado's growing population will also increase water demands. We may well see an increased fire danger even in winter, and certainly in the warmer months.

In addition, higher temperatures will shorten the cool weather in both spring and fall for folks at the lower altitudes, endangering cool weather crops such as peas, lettuce and spinach while simultaneously benefitting beans, tomatoes, zucchini, etc. We can anticipate a need to protect our gardens against the sun and increased heat with such aids as shade netting, and indeed, the use of shade may well become a necessary part of garden planning for the hottest months in Colorado, as an attempt to slow too-quick maturation and reduced harvests.

As gardeners, we're often possessive and protective about our own plots of earth. The garden is our place, after all, a place where many of us feel closest to nature. We decide what and when to plant and harvest, and when to prepare the bed. Such effort and commitment encourages us to listen to the seasons. That's good. It's a skill we'll be using more and more in the coming years - if the climate change reports are true. But even with change, perhaps drastic change in some areas, life goes on. Especially in our gardens, if we have anything to say about it. And we actually have a lot to say.