General Winter Care for Your Trees, Shrubs, Ornamentals, and Lawn in Non-Dormant Climates: Protecting Plants in Mild Winters

Winter Challenges in Non-Dormant Climates

Warm climate winters present many unique challenges to property owners looking to protect their landscape during colder months.

Unlike cold-climate plants that enter true dormancy, most warm-climate plants remain active year-round. This makes them particularly vulnerable to insects, diseases, and other seasonal challenges, so it’s important to keep a careful eye on them.

This guide will help you protect your landscape during the mild winter months, ensuring your plants thrive when spring arrives.

How to Prevent Winter Stress

In our mild winters, the main threats aren't deep freezes, but drought, unexpected frosts, and flagging insect management. Here’s how to tackle each one:

Water Deeply, But Less Frequently: If you hit a dry spell of 2-4 weeks without rain, give your plants a deep, slow drink. Morning is best, on a day when temps will stay above 40°F. Pay special attention to anything you planted this year—their roots aren't established yet.
Don’t Underestimate the Power of Mulching: A 2-3 inch layer of organic mulch (like wood chips or pine straw) is your best friend. It locks in soil moisture, suppresses weeds, and buffers roots from sudden cold snaps. Just pull it a few inches away from the trunk to prevent rot.
Keep Frost Protection On Hand: It’s wise to have burlap, frost cloths, or even old sheets available to cover vulnerable plants when unexpected freezing temperatures hit. For especially vulnerable plants, consider adding a string of incandescent Christmas lights under the cover to provide a few degrees of warmth. Finally, remember to water the soil before a frost, as moist soil retains heat better than dry.
Don’t Fertilize: If you live in a warmer climate, avoid fertilizing trees and shrubs in late fall and winter. It’s tempting to want to give your landscape a boost, but fertilizer encourages tender new growth that is highly susceptible to frost damage, so it’s best to wait until late winter or early spring, when the occasional freezing temperature is less likely.

Pruning for Health and Structure in the Cool Season

It might feel counterintuitive to cut things back in winter, but with the leaves gone, it’s the perfect time to see the shape and underlying structure of your trees. To prune effectively:

Start with the "Three D's": Remove any dead, diseased, or damaged wood.
Improve Structure: Target crossing or rubbing branches and any weak attachments that could fail in a storm.

A Critical Exception: Avoid pruning spring-flowering trees and shrubs like azaleas, camellias, and lilacs in winter, as you will remove the buds that become next year’s flowers. Instead, prune these plants immediately after their spring bloom.

For significant shaping or if you are unsure about the best timing for a specific plant, consult a certified arborist for help.

Protecting Your Landscape from Winter Insects and Diseases

In colder climates, hard freezes limit insect activity and reduce population, which diminishes the threat they pose to trees and shrubs. In warmer climates, however, many insects and diseases remain active all winter, so homeowners must remain vigilant in their fight against them.

Scale, Aphids, and Mites: These sap-sucking insects can thrive in cool weather, weakening plants and leading to issues like sooty mold. Dormant or horticultural oils can be an effective treatment during the cooler months, though it’s important to note that these oils should only be applied when temperatures are consistently above 40°F.
Fungal Diseases: Cool, humid weather is ideal for the development of fungal diseases like powdery mildew, while root rot typically develops in wet soils. Ensure your plants have good air circulation by avoiding overcrowding and be sure to clean up fallen leaves and debris from around their bases.

If you spot signs of insect infestations or tree diseases, or if you’re unsure, call an arborist for help.

Winter Grass Care For Mild Climates

Caring for your lawn and grass in mild climates depends on whether you have warm or cool-season grasses.

Warm-Season Lawn Winter Care (Bermuda, Zoysia, St. Augustine)

In mild winters, these grasses will typically enter a slowed, semi-dormant state, especially as temperatures consistently drop.

Mow High as Growth Slows: For your last few mows of the season, gradually raise the mower height. The taller grass blades help insulate the roots and crown from cooler temperatures.
Keep it Clean: Rake or blow away fallen leaves and debris to prevent matting, which can smother the grass and encourage mold and insects.
Control Winter Weeds: Slowed or dormant lawns are prime targets for winter annual weeds like chickweed and poa annua. Apply a pre-emergent treatment in the fall to prevent weed seeds from germinating.

Cool-Season Grasses Care (Fescue, Rye)

To keep a green lawn through winter, many homeowners in mild climates over-seed with cool-season grasses like fescue and rye. These grasses thrive in the cooler weather, providing lush color during colder months, but they still require careful care.

Watering is Key: These grasses grow through winter and need consistent moisture. Water deeply and regularly, especially during dry spells.
Continue Mowing: You’ll likely need to mow throughout the winter, but less frequently. Keep the blade sharp to ensure a clean cut.
Control Winter Weeds: Broadleaf weed control may still be needed to keep winter annuals and other hard to control perennials such as ground ivy and thistles in check.

Need a Customized Winter Care Plan for Your Landscape?

Mild winters present unique opportunities and challenges. If you're unsure about the specific needs of your trees, shrubs, or lawn, consult with an ISA Certified Arborist for an expert opinion.

Schedule a free consultation today, and our experts will create a tailored lawn care plan to help your property thrive.