Perennial Herbs

Overwintering Herbs: A Comprehensive Guide

Introduction

Overwintering herbs is a crucial step for gardeners in cold climates who want to enjoy fresh herbs all year round. Different herbs have varying levels of cold tolerance, so it’s important to understand your plant’s specific needs before preparing it for winter. This article will provide a comprehensive guide to overwintering herbs, including tips on pruning, mulching, and protecting tender perennials.

Determining Cold Hardiness

The first step in overwintering herbs is to determine their cold hardiness. This refers to the lowest temperature a plant can tolerate without sustaining damage. You can find this information on plant tags or by searching online using your favorite search engine. Once you know your plant’s cold hardiness, you can determine the best overwintering strategy.

Preparing Herbs for Winter

Fertilizing: Avoid fertilizing your herb garden after August. Late-season fertilization encourages tender new growth that may not survive the winter.

Watering: Water plants regularly throughout late summer and autumn. Drought-stressed plants are more susceptible to cold weather damage. If the winter is dry, provide occasional irrigation (when the ground isn’t frozen).

Pruning: Many perennial herbs need to be pruned before winter. Cut them back to a height of 4 to 6 inches after the first few hard freezes. This helps reduce wind damage and encourages new growth in spring.

Mulching: Mulching herbs helps protect their roots from cold temperatures. Apply a 3 to 6 inch layer of mulch, such as chopped leaves, straw, or pine needles, after the first hard freeze. Avoid mulching too early, as it can trap moisture and damage plants.

Overwintering Perennial Herbs

Many perennial herbs are winter hardy, meaning they can survive cold winters with minimal protection. These include:

• Chives
• Thyme
• Mint
• Fennel
• Oregano
• Lavender
• Tarragon

In most climates, these plants need nothing more than a good pruning after the first hard freezes. However, in colder climates (USDA plant hardiness zone 5 and below), they may benefit from a layer of mulch.

Protecting Tender Perennials

Some perennial herbs, such as rosemary, bay laurel, and lemon verbena, are less winter hardy. These plants need extra protection during the winter months. Cut them back nearly to the ground after the first hard frost, then cover them with soil and top the soil with 4 to 6 inches of mulch. A layer of evergreen boughs can also provide additional protection from harsh winds.

Overwintering Annual Herbs

Annual herbs, such as dill and coriander, survive for only one growing season. They will be killed by the first frost. There isn’t much you can do to overwinter annual herbs, but be sure to pull them up and clear the area of plant debris. This will help prevent pests from overwintering in your garden.

Overwintering Herbs Indoors

If you’re concerned that your tender perennial herbs may not survive the winter outdoors, or if you want to continue using annual herbs year-round, many herbs can be overwintered indoors. Pot up herbs like parsley or basil in autumn, then move them back outdoors in spring. Some container herbs can also be given winter protection outside by placing them in a sheltered location and covering them with a thick layer of mulch.

Conclusion

Overwintering herbs can be a rewarding experience that allows you to enjoy fresh herbs all year round. By following the tips outlined in this article, you can help your herbs survive the winter and thrive in the spring.