Q: I have heard that some weeds and insect pests have been wiped out by the record cold weather this winter. Please tell me this is true, and I don't have to worry about so many bad things in my garden this summer. I want good news to come from such a long and cold winter.

A: I hate to be the bearer of bad news, but the record cold may not have had as much of an effect as you were hoping for. Partly because it really wasn't that cold and partly because of how much snow cover there was.

The bigger problem for insects and plants has been the duration of the cold. The longer it stays cold, even if it isn't record breaking, is more likely to kill insects and plants. It is kind of like a person dropping into the ice-cold water during a Polar Plunge versus staying out in average winter cold for a week or two. The Polar Plunge may be a shock to the system, but trying to survive the cold for a long time is harder.

To look at the situation more analytically, compare your location to the natural range that the pest lives in. Let us say you live in St. Louis, and the pest's normal range is from Dallas to Minneapolis. The pest naturally tolerates the very cold Minnesota winters and the hot Texas summers. There are natural regional differences in the populations of animals and plants, so some of the individuals of the pest from the southern area may not be as cold tolerant. Therefore, a few of the St. Louis pests may have been harmed by the cold, and down at the extreme southern end of the range, more of the pest may have been harmed.

If the extreme cold of Minnesota dropped down to Dallas for a few days that is like the Polar Plunge, but the pest species is capable of surviving the whole winter of that cold temperature in Minnesota. Now, if a Southern pest species had made its way north to St. Louis, then maybe it would be killed.

Most areas in the eastern two-thirds of the country had many record cold days, but they may not have been as bad as you think. Often the record cold was for that individual day, such as, "It has never been this cold on Jan. 7," while the record for Jan. 8 was even colder. Or it was often said, "It hasn't been this cold in 20 years." Unfortunately, insect pests have been around and surviving record cold for hundreds of centuries not just the past 20 years.

The other factor was the amount of snow covering the ground. In many places, there was a lot of snow on the ground before the cold came. Any insect or weed pests covered by the snow were protected to some extent. The snow was also protecting our perennials and the roots of our trees and shrubs.

Insect populations often expand into new territory. While it may be true that some new types of insects are reduced in colder areas, it won't be a long-lasting effect. It is also unlikely that any weed plants were affected by the cold, as most cold region weeds are very hardy.

On the other hand, gardeners often install plants from warmer regions in their gardens. If they were not given protection from the cold, they may have been killed over the winter.

Buds, bulbs, crowns, seeds and roots on northern plants stay dormant until they have reached a minimum number of hours of cold, known as a chilling requirement, chilling unit or chilling hours. After the chilling requirement is met, the plant can begin to sprout in the spring. Early spring blooming plants have a lower requirement for chilling than late spring bloomers.

A bigger problem may still exist. When we receive warm temperatures, many plants will begin to sprout. Most northern trees, many shrubs and most early spring blooming bulbs and perennials will open their flower buds first. If we get another drastic cold spell while the flower buds are vulnerable, they will be killed and fewer fruit will be produced.

Email questions to Jeff Rugg at [email protected]. To find out more about Jeff Rugg and read features by other Creators Syndicate writers and cartoonists, visit the Creators Syndicate website at www.creators.com.