By Lorraine Sharaf
Beneath frozen ground and bare branches, winter temperatures trigger biological processes that limit pests, reset plant growth, and shape the success of the growing season ahead.
Whether you love them, hate them, or a little of both, cold snowy winters do important work for farms and gardens—work that becomes easier to overlook as winters in southeastern Pennsylvania grow warmer overall and more unpredictable from year to year.
Freezing temperatures help reduce the number of insects and pathogens that survive the winter. That matters for crops, but also for people. Sustained cold helps suppress mosquitoes and ticks and slows the northward spread of harmful insects that thrive in warmer southern climates. When winters are mild, more pests survive, emerge earlier, and expand their range—raising pressure on farms and increasing risks to human health.
Cold also plays a key role in plant dormancy, which is often misunderstood. Dormancy isn’t like a bear hibernating. Bears drop their body temperature to a few degrees above freezing and drastically reduce their respiration and heart rates to survive the winter temperatures. They live off their fat stores and do periodically wake up during the winter. Many trees and perennial plants actively enter a resting phase in late fall, triggered by shorter days and cooling temperatures. To fully reset and wake up properly in spring, many plants—especially fruit trees, berry bushes, garlic, and flowering perennials—must experience a certain amount of winter cold, known as chill hours (time spent below about 45°F). This cold acts like a biological reset button. Without enough of it, plants may leaf out unevenly, flower poorly, or produce lower yields. Read Understanding Plant Dormancy for more information about plant dormancy.
Winter cold benefits soil as well. Freeze–thaw cycles help loosen compacted ground, improving air and water movement, while snow cover insulates soil life and slowly replenishes moisture as it melts. These processes support healthier roots, stronger early growth, and more resilient crops.
As winters become less consistently cold, these natural systems don’t always reset as reliably. When true winter cold does arrive, it plays an increasingly important role—reducing pests, supporting plant health, and laying the groundwork for productive farms and gardens in the seasons ahead.
So, go ahead and enjoy a proper winter! Walk and ski through the woods, take photos, build a snow village and maybe toss a snowball. Then come inside with a hot beverage and plan out this year’s crops and gardens.
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