First Frost Yard and Garden Tips

Happy fall! Cooler temperatures are on the way, and the first freeze along Colorado’s Front Range is just around the corner. Now is the time to prepare your waterwise garden for winter.

If you have a Garden In A Box garden, continue following the shoulder-season watering guidelines in the Watering Guidelines section of your Plant & Care Guide until the first freeze. Once temperatures drop, a few simple steps can help protect your plants, prevent costly sprinkler damage, and set your garden up for success next spring.

Here’s how to prepare your Colorado garden for winter.

1. Winterize Your Sprinkler System Before the First Freeze

One of the most important fall yard maintenance tasks in Colorado is winterizing your automatic sprinkler system. When water remains in irrigation pipes during freezing temperatures, it can freeze, expand, and cause pipes or sprinkler components to crack. Repairs can be expensive, so it’s best to take care of this before temperatures drop.

Blowing out your sprinkler system is one of the most effective ways to remove remaining water from the pipes. This process uses compressed air to clear the lines before winter. You’ll also need to turn off your irrigation controller and shut off the appropriate water supply to your sprinkler system, including the backflow preventer according to its instructions.

We strongly recommend hiring an irrigation professional to blow out your sprinkler system. Fall is a busy season for sprinkler companies, so schedule your appointment early to beat the first freeze.

Resource Central does not endorse specific irrigation companies, but you can use the Irrigation Association’s certified professional directory to find a qualified specialist in your area.

Prefer to winterize your sprinkler system yourself? If you have the right equipment and experience, these resources can help you learn more:

When in doubt, leave this task to a professional to help prevent damage to your irrigation system.

2. Protect Your Perennial Garden From Fall Frost

The good news for Garden In A Box gardeners is that all our plants are hardened off. This means they have been acclimated to outdoor conditions, including sunlight, wind, and temperature fluctuations. These hardy perennials are prepared for seasonal changes and will soon enter dormancy for the winter.

Even so, a little extra care can help newly planted perennials adjust to their first Colorado winter.

Cover Newly Planted Perennials Before a Frost

If you planted your perennials less than a month before the first frost, consider protecting them during the first few freezes. Established hardy perennials generally need less protection, so covering them is often a matter of preference and local conditions.

Freezing temperatures without snow can be particularly challenging for new plants. Snow provides a natural layer of insulation, helping buffer plants from cold air temperatures. If a freeze is expected before snowfall arrives, temporary protection may be helpful.

You can use everyday household items to cover plants, including:

Cardboard boxes
Old sheets or linens
Milk jugs with the bottoms removed
Inverted flowerpots
Buckets

Make sure the covering reaches the soil to help trap warmth around the plant. Use stakes or another support to keep the material from resting directly on foliage whenever possible.

Cover plants before sunset on the evening before an expected frost, then remove the coverings the following morning. This allows plants to benefit from daytime warmth and sunlight.

Don’t Worry About Some Fall Plant Dieback

After the first few freezes, you may notice wilted, discolored, or damaged foliage. This is a normal part of the transition into winter dormancy for many perennial plants.

Even if the foliage looks less lively, your plants can still be establishing and maintaining their root systems beneath the soil. As temperatures cool, many perennials naturally direct their energy toward surviving winter and returning in spring.

Avoid assuming a plant is dead just because its leaves have changed. Give your garden time to rest, and check for new growth when the growing season returns.

Refresh Your Garden’s Mulch

Mulch is one of the simplest ways to support a healthy, waterwise garden throughout the year. It helps retain soil moisture, moderate soil temperatures, and protect plant roots from temperature fluctuations.

Before winter sets in, check the mulch around your garden. If the layer has thinned or become uneven, refresh it as needed, taking care not to pile mulch directly against plant crowns.

A healthy layer of mulch can help your garden conserve moisture and prepare for the changing conditions ahead.

3. Remember to Water Your Garden During Winter

Colorado’s dry climate means garden care doesn’t stop when the growing season ends. Winter watering is important for many trees, shrubs, and perennial gardens, especially during extended dry periods when the ground is not frozen.

Even dormant plants can lose moisture, and Colorado’s sunny, windy winter weather can dry out soil. If conditions allow, occasional winter watering can help protect plants from dehydration.

Follow the winter watering recommendations in your Garden In A Box Plant & Care Guide, and adjust based on precipitation, soil conditions, and the weather. Water during a warmer stretch when the ground is unfrozen, allowing moisture to soak into the soil without creating standing water or icy conditions.

Stay tuned for more winter garden care tips to help your waterwise landscape thrive through Colorado’s coldest months.

Get Ready for Another Season of Waterwise Gardening

A little fall preparation goes a long way. Winterizing your sprinkler system, protecting newly planted perennials, refreshing mulch, and planning for winter watering can help your garden weather the colder months.

Want to be among the first to hear about next season’s Garden In A Box gardens? Sign up for spring 2027 Garden In A Box updates to get seasonal gardening tips, sneak peeks of new garden designs, and reminders when the next sale approaches.

Here’s to a healthy garden and a little less outdoor work when winter arrives!

Frequently Asked Questions About Fall Garden Care in Colorado

When should I winterize my sprinkler system in Colorado?

Winterize your sprinkler system before the first hard freeze, which can arrive early in fall along Colorado’s Front Range. Schedule a professional sprinkler blowout in advance, since irrigation companies are often busy during this time of year.

Do I need to cover my Garden In A Box plants before a frost?

Established Garden In A Box perennials are hardy and do not need to be covered for every frost. However, plants installed shortly before freezing temperatures may benefit from temporary protection during their first few freezes, especially if snow has not yet arrived.

What can I use to cover plants during a frost?

You can use cardboard boxes, old sheets, buckets, inverted flowerpots, or milk jugs with the bottoms removed. Cover plants before sunset and remove the coverings the next morning. Whenever possible, keep the material from resting directly on the foliage.

Do I need to water my garden in the winter in Colorado?

Yes, occasional winter watering can be important during dry periods, particularly for newly planted perennials, trees, and shrubs. Water on warmer days when the soil is not frozen, and follow the recommendations in your Plant & Care Guide.

What does it mean when plants are hardened off?

Hardened-off plants have been gradually acclimated to outdoor conditions, including sunlight, wind, and temperature changes. Garden In A Box plants are hardened off before planting, helping them adjust to outdoor life and prepare for seasonal temperature fluctuations.

How can I get ready for next year’s Garden In A Box season?

Join the Garden In A Box interest list to receive updates about upcoming garden designs, seasonal care tips, and sale announcements from Resource Central.