This fall has been an unusual season in an already unusual year for many gardeners across the southeast. We were fortunate enough to be outside the path of hurricane Helene, but other seed growers and farmers were not so lucky. Aside from that major catastrophe, average annual temperatures have increased across the region and there’s been significant drought, storms, or flooding in certain areas. Many growers are now hoping season extension can provide some relief during this season and allow for production during the fall, winter, or early spring.

Season Extension Guides & Resources

Season extension can be a great way to overwinter biennial seed crops, produce more crops for market, or just grow a bit more food for your family. Here are a few of our favorite resources to help you make it happen:

University of Maryland Extension High Tunnel Best Management Practices by Neith Little

UMD has put together some great basic information for managing a greenhouse or hoop houses of any size. Learn more about pest management, soil care, crop selection, temperature management and more.

Read High Tunnel Best Management Practices here.

Caterpillar Tunnel: An Inexpensive Variation on the Hoophouse Theme by Growing for Market.

A quick guide to setting up an inexpensive caterpillar tunnel, which is a great option where purchasing a hoop house isn’t possible.

Read the Caterpillar Tunnel guide here.

Fine Gardening Easy-to-Build Cold Frame by Rob Wotzak

Working with a small space? This article offers comprehensive, easy to follow instructions to build your own cold frame. “This plan doesn’t require a lot of tools, a contractor’s license, or 500 trips to the hardware store.”

Read Easy-to-Build Cold Frame here.

How to Grow Winter Hoop House Crops – Mother Earth News Magazine Article by Pam Dawling

Our neighbor over at Twin Oaks Community, Pam Dawling, wrote this helpful guide. She was their garden manager for several years, is the author of Sustainable Market Farming, and runs a blog under the same name (Sustainable Market Farming) full of helpful, well-researched articles.

Read How to Grow Winter Hoop House Crops here.

Year-Round Hoophouse, The: Polytunnels for All Seasons and All Climates by Pam Dawling

Dive deeper with Pam Dawling’s book on hoop houses. This is a thorough, clear and easy-to-follow guide for designing and building a hoophouse and making a success of growing abundant, delicious fresh produce all year round, in any climate, for market or just your family.

Purchase Year-Round Hoophouse here.

Michigan State University Extension Common Diseases in Organic Hoophouse Greens by Colin Thompson

Plant diseases can occur throughout the year, not just in summer. Sensitive greens can be especially challenging and prone to fungal diseases in low-airflow winter hoop houses. This article offers helpful tips for mitigating that risk.

Read Common Diseases in Organic Hoophouse Greens here.

Four Season Harvest by Eliot Coleman

Eliot Coleman’s Four Season Harvest is renowned in the Northeast. This helpful guide has information needed to grow year-round even through the cold winters he experiences in Maine. This is a great guide for those growers in mountainous areas that deal with severe winters.

Purchase Four Season Harvest here.

SESE Blog 10 Season Extension Techniques by Jordan Charbonneau

New to season extension? Try one of these simple techniques to keep growing through all conditions from the SESE blog.

Read 10 Season Extension Techniques here.

University of Kentucky Extension Season Extension Tools & Techniques

Get the basics on season extension from floating row cover to high tunnels plus tips on economic considerations, irrigation, cultivar selection and more.

Read Season Extension Tools & Techniques here.

NCAT ATTRA Crop Selection and Planting Schedules for Winter High Tunnel Production by Chris Lent

Find crops and a planting schedule that works for your area with this helpful guide from NCAT. It also includes links to other resources on hoophouse production.

Read Crop Selection and Planting Schedules for Winter High Tunnel Production here.

Beginner Tips for Using Season Extension

• Be sure to account for dwindling daylight in your days to harvest, not just cold temperatures.

• Watch for signs of fungal diseases and remove affected material immediately.

• Select varieties and crops bred for cold hardiness and disease resistance.

• Vent your season extension whenever it’s warm enough to do so.

• Double up on temperature protection by using frost cover or low tunnels within a hoop house.

• Use your season extension to help harden off seedlings in the spring.

Many of our favorite aromatic herbs are perennials that are perfect candidates for overwintering in gardens of the Southeast. Herbs like lavender, sage, thyme, and mint all add incredible flavor to meals and beverages or value to your farmer’s market offerings. While some herbs are cold hardy, others need more help if we want to grow them year round. Learn more about how you can overwinter herbs.

What Herbs Can I Overwinter?

There are many excellent herbs you can overwinter in the Southeast, though some need more care than others. Here’s a list of all the herbs you can overwinter, divided into categories based on their cold tolerances. Keep in mind, conditions like soil moisture, wind exposure, and snow cover can affect a plant’s cold tolerance.

You’ll find hardiness USDA hardiness zones listed next to each herb, but further on, we’ll discuss ways to push those limits.

Extremely Cold Hardy Perennial Herbs 

• Peppermint (Zones 3-11)
• Lemon Balm (Zones 3-9)
• Horehound (3-9)
• Chives (Zones 3-9)
• Horseradish (Zones 2-9)
• Leverage (Zones 3-9)
• Sorrel (Zones 3-9)

You can also grow some of these cold hardy herbs farther south if you maintain consistent watering and offer them shade from the afternoon sun in the summer months.

Moderately Cold Hardy Perennial Herbs

• Tarragon (Zones 4-9) 
• Wild Bergamot (Zones 4-8)
• Winter Savory (Zones 4-8)
• Lavender (Zones 5-9, depending on cultivar)
• Thyme (Zones 5-9)
• Sage (Zones 4-10)
• Oregano (Zones 5-10)
• Fennel (Zones 4-9)

Delicate Perennial Herbs

• Rosemary (Zones 8-11) 
• Ginger (Zones 9-12)
• Turmeric (Zones 8-11)
• Lemon Verbena (Zones 8-11)
• Basil (zones 10-11)

Soil Conditions to Overwinter Herbs

Soil conditions can have a surprising effect on whether our herbs make it through the winter. Generally, herbs thrive in loose, well-drained, fertile soil with a pH between 6.0 and 7.5. Many of our favorite herbs, like sage, fennel, rosemary, and lavender, are native to the Mediterranean and other regions with warm sunny days and loose, well-draining soil. 

Heavy clay soils abundant in much of the Southeast can be problematic for these perennials. Avoiding low, wet spots and amending your soil with plenty of compost, peat moss, or aged manure can improve your soil’s drainage and pH to give your herbs a better chance. Raised beds are also a good option for areas with poor drainage.

Mulch

No matter which herbs you choose, from cold hardy to delicate, mulch is one of the best ways to improve their chances of surviving the winter. Mulch acts as insulation over the soil. In the fall, it can help keep soil temperatures warmer long. As it helps to moderate soil temperatures, it reduces the effects of freeze and thaw cycles, preventing soil from heaving.

However, it’s important to know that mulch can also hold in excessive moisture. If you have wet periods but not extreme cold temperatures, go lighter on the mulch. As discussed above, soil quality and drainage are critical for the survival of many herbs, like lavender. 

Use Row Cover to Overwinter Herbs

One of the easiest ways to offer any plants some extra winter protection is to set up floating row cover. Using wire or other hoops, suspend frost cloth or plastic above the tops of the plants, venting or removing on warm days. This method is not only affordable, but one of the best because you can add or remove it as needed throughout the season. 

Overwinter Herbs in Greenhouses & Hoop Houses

If you’re among the gardeners lucky enough to have the space and resources for a greenhouse or hoop house, dedicating a spot for perennial herbs may help you overwinter cultivars that would not typically survive in your zone.

In cold climates or mountainous areas, combine your hoop house or greenhouse with low tunnels or frost blankets to give your herbs some extra protection on wintry nights. 

Disease Issues

Fungal diseases like powdery mildew, downy mildew, and root or crown rot are the primary diseases issues we see herbs succumbing to over the winter. Prevention is key with these diseases. Whether you amend your soil, or create raised beds, good drainage is essential. 

Airflow is also important when you overwinter herbs. Space herbs appropriately, and divide them as needed. When you’re growing in hoop houses or low tunnels, it’s important to vent them whenever it’s warm enough. 

For some herbs, you may also find some mildew-resistant cultivars.

If you see signs of a fungal disease, remove affected foliage immediately. Improve circulation if possible, using vents and fans in hoop houses. You may treat your plants with a homemade or commercial fungicide, like baking soda or commercial fungicides. Keep in mind that commercial fungicide, like copper, can build up in the soil and become detrimental. 

Spring Care for Overwintered Herbs

If you live in a cold climate, and mulched your herbs in heavily, pull some of the mulch back in the spring to allow more airflow. Many herbs are susceptible to high moisture, rot, and fungal issues.

No matter how well you care for your herbs, you will probably see some die back. In the spring, you can trim any dead tips or branches to make room for fresh growth.

Topdressing your beds with finished compost can give your plants a boost as they begin to grow. The compost will add fertility and improve soil structure. 

Every vegetable patch needs a section for garlic! Garlic offers tons of flavor with minimal effort. It’s an excellent option for beginners because it’s pretty easy to grow, takes up relatively little space, stores well, and is easy to save from year to year. Once you buy garlic, you won’t need to purchase it again. Raised beds are often the preferred choice for growing garlic, but they aren’t your only option. In this post, we’ll dig into garlic’s soil requirements and why you may or may not want to install raised beds. 

Garlic Soil Requirements

Soil structure is the most important feature to consider when growing garlic. The roots need as much air as they need water. Garlic performs best, forming the largest bulbs, in loose, well-drained soil. Sandy loam is ideal, but few people are blessed with soil like this.

If you’re working with heavy clay or sand, the best thing you can do is work plenty of organic matter into your beds. Add compost, well-aged manure, peat moss, rotted-down sawdust, or a combination. Growing a cover crop in your bed before planting garlic is another great method for building soil structure. 

If you haven’t done so already, a soil test can be helpful for garlic and all your other crops. Garlic and onions prefer a relatively neutral pH between 6.5 to 7.0. Soil outside this range that is too acidic or too alkaline will slow garlic’s growth and cause late maturity.

See more about amending soil and signs of nutrient deficiencies in our full garlic growing guide.

Raised Beds for Garlic Pros and Cons

Building raised beds is one solution to quickly provide good soil for garlic. There are a few pros and cons you should consider before you begin.

Raised Beds for Garlic Pros

• Raised beds quickly provide excellent, deep, loose soil for garlic.
• They warm up quickly in the spring.
• Raised beds usually drain well.
• Raised beds are generally easy to maintain and may help lessen weed pressure.

Raised Beds for Garlic Cons

• Bringing in soil, compost, and/or building materials can be costly.
• Raised beds may dry out more quickly and need watering during the summer.
• Eventually, raised beds may need to be repaired or replaced.

Traditional Beds for Garlic Pros and Cons

It’s also perfectly acceptable to grow garlic right in the ground in a traditional garden bed. Like raised beds, this method comes with its pros and cons.

Traditional Beds for Garlic Pros

• No construction is needed, and you won’t have to repair or maintain raised beds.
• Traditional beds are easy to till.
• Traditional beds are easy to incorporate into large irrigation or watering systems.

Traditional Beds for Garlic Cons

• They may have dense clay soil or nutrient-poor sandy soil that may take a while to amend.
• Traditional beds tend to have poorer drainage and may stay wet in the spring.
• Traditional beds may be more susceptible to erosion and weed pressure.

How to Design Raised Beds for Garlic

If you’ve decided that raised beds are right for you, it’s time to start planning. Generally, it’s a good idea to lay things out on paper before you begin construction.

Ideally, raised beds should be at least 12 inches deep. Their length doesn’t matter, though you may want to break one long bed into a few smaller ones to create working pathways. Their width is also a personal choice, but you should be able to easily reach into the middle of the bed to weed, plant, and harvest without standing in it. Many folks create beds 3 to 4 feet wide for this reason.

You also want to think about the location of your raised beds. Ensure they get plenty of sunlight and are within reach of your garden hose or irrigation system.

If you’re building multiple raised beds or placing them near other structures, it’s also a good idea to leave pathways around your beds that are at least wide enough to fit a wheelbarrow.

Remember that plant roots will often grow deeper than your raised bed. Don’t place a raised bed on any area contaminated with chemicals.

Once you’ve got a plan, you can frame up your raised beds. You can make raised beds from logs, rot-resistant lumber like black locust or cedar, stones, bricks, or blocks. Avoid using tires, pressure-treated lumber, or any materials that could leach chemicals into your food-producing beds. Depending on the material you use, corners can be held together with stakes, plumbing straps, or screws.

Fill your beds with good quality soil and compost or just finished compost. You will need more material than you think as it will settle. You should fill at least 12 inches deep with compost or good soil. Adding compost to the bed each year is also a good idea.

How to Design Traditional Beds for Garlic

While some gardeners prefer raised beds, many growers still find plenty of success growing garlic in the field. If you decide this is the best method for you, there are a few things to consider when preparing your beds. 

Garlic hates to have soggy feet. If you have space to work with, always locate beds for garlic and other alliums in your highest or best-draining areas. Low spots that stay consistently wet through the spring and early summer will make for a poor harvest.

Prepare your beds by adding plenty of organic matter either through cover cropping ahead of time or working in compost, peat moss, old rotted sawdust, or aged manure. As mentioned above, a soil test and any necessary amendments are also a good idea whether you need to change the pH or increase fertility.

Many people choose to till new beds, but you can also loosen the soil with a broad fork or garden fork for a no-till option. This is also a good choice for gardeners working in small spaces. Forks allow you to lift and loosen the soil without turning it over. 

Garlic Growing Tips

Garlic is generally an easy keeper, but there are a few things to remember that can improve your harvest. 

• Water garlic consistently if you don’t have much rainfall during its spring and summer growing period.
• Garlic doesn’t compete well with weeds. Keep your patch well-weeded for the biggest bulbs.
• Select an appropriate type of garlic for your garden and climate zone.
• Plant your garlic at the proper depth and spacing.
• Mulch garlic well with old leaves, straw, or hay.
• If you’re growing hardneck or Asiatic garlic, remove the scapes when they’re eating stage for the best bulb production.
• Use a garden fork to gently harvest bulbs and cure and store them properly.