Winter Watering in Denver: Keeping Your Garden Alive in the Cold

Winter in Denver can be brutal. The dry air, fluctuating temperatures, and occasional snow make it easy to forget that your plants still need care. But contrary to popular belief, winter watering is essential. While your garden may seem dormant, many plants are quietly growing below the surface, needing moisture to stay healthy. Without it, roots can dry out, leaves can burn, and trees can suffer long-term damage.

Why Winter Watering Matters

Although winter in Denver often means frozen ground, the air remains dry, and plants still lose water through transpiration. Transpiration is the process by which plants release water vapor through their leaves. Even in winter, evergreen trees, shrubs, and some hardy perennials continue to transpire, albeit at a slower rate. If the roots can’t access moisture because the soil is frozen, dehydration becomes a serious concern.

The unique challenge in Denver is the combination of cold and dry conditions. While snow can help insulate the ground, it doesn't always provide enough moisture to replenish what the plants lose. In fact, a lack of snow cover can exacerbate the issue. Without supplemental watering, plant tissues can dry out, and evergreen needles may become scorched or “burned” by the cold, a phenomenon known as winter burn.

When to Water

Timing is key. Plants don’t need water every day in winter, but they do need periodic moisture during dry spells. Water on days when temperatures are above freezing—ideally in the 40s or 50s. The key here is to make sure that the water can seep into the soil before temperatures dip again. When the ground is frozen, water can’t penetrate, and applying it to frozen soil can lead to runoff or ice formation.

A good rule of thumb is to water every 4-6 weeks, depending on the weather. If it’s been particularly dry or windy, your plants may need more attention. Keep an eye on the forecast—long periods of warm temperatures followed by a sudden freeze can catch gardeners off guard.

How to Water Effectively

Forget the quick splash. Since the surface soil can be frozen, you’ll want to make sure the water can reach the deep root zone, which may still be thawed and active. Use a garden hose with a gentle nozzle to ensure that water is applied slowly and deeply for 30 minutes to-1 hour per plant, depending on your flow rate. I like to use "smaller than my pinky" guide for the stream if using a regular hose.

Water early in the day—before noon is best—so the moisture has time to soak in. When temperatures drop below freezing overnight, any excess water left on the surface can form ice, damaging plants or making walkways hazardous.

What to Water

Focus on evergreens and shrubs—they’re the plants most susceptible to winter dehydration. Evergreens continue to lose water through their needles during the winter, so they need moisture to avoid desiccation. Their root systems, however, may be deeper in the soil and less affected by surface freezing. Watering thoroughly helps these plants access water and stay healthy through the colder months.

It’s important to note that while deciduous plants (those that lose their leaves in winter) typically don’t need as much attention during this time, some hardy shrubs and trees still benefit from occasional watering. Check them periodically to ensure they aren’t too dry.

The Science of Winter Watering

Winter watering works by counteracting the moisture loss that continues even when temperatures drop. When plants transpire, they lose water through small pores in their leaves called stomata. In winter, even though stomata are less active, some water loss still occurs. If the ground is frozen, these plants can’t take up the water they need, leading to stress and possible damage to the plant’s cellular structure.

The goal of winter watering is to ensure that moisture reaches the root zone where it can be absorbed, even if the surface soil is too cold to allow movement. As long as temperatures are above freezing, water will infiltrate deeper soil layers, providing the roots with much-needed hydration.

The Art of Winter Watering

Winter watering isn’t about giving your plants a “winter vacation” from your care. It’s about the quiet work of ensuring they’re not forgotten during the harsh months. Like a hand on a friend’s shoulder in a hard season, watering in winter offers your plants a steady presence—a simple but profound act that can make the difference between survival and decline.

So, as you bundle up for another cold Denver day, don’t forget to check in on your plants. They’ll be grateful for the life-giving moisture, and come spring, you’ll have a garden ready to burst back into bloom.

Carol's Garden finegardening.com