From time to time on the podcast, we’ve touched on growing herbs, but this week’s episode is the first that is dedicated solely to growing herbs. My guest to help us dive into this topic of these workhorse plants for every garden is horticulturist Sue Goetz, whose new book, “Complete Container Herb Gardening,” was published just last month.
Sue is a garden designer who lives and gardens in Washington state. Her work has earned the Sunset Magazine Western Living award, the Fine Gardening Best Design Award, the American Horticultural Society Environmental Award, and gold medals at the Northwest Flower & Garden Show. Sue’s business is named Creative Gardener, and she strives to inspire gardeners to create.
Sue’s latest book is her third on growing and using herbs. “Complete Container Herb Gardening” is designed for both gardeners with plenty of space and those who live in apartments or condos with limited opportunities for growing.
Most of us get started with herbs by growing basil or rosemary in a pot on a windowsill, but Sue’s book will take you further by explaining how to raise herbs in containers outdoors and how to propagate herbs for an endless supply of plants.
Sue is a wealth of knowledge on herbs, and her book offers easy-to-implement advice for taking advantage of all that herbs have to offer gardeners. The book includes more than a dozen “container recipes” for mixing herbs to complement each other and for specific goals, such as attracting pollinators into a vegetable garden.
In addition to exploring the culinary and beverage uses of various herbs, Sue’s book has instructions on how to use herbs for skincare treatments and in homemade housekeeping products.
Aside from how easy herbs are to grow, what drew Sue to herbs is their diversity, utility and versatility. Herbs, more so than any other plant category, have uses in cooking, flavoring, healing and fragrance making.
What Makes a Plant an Herb
While Sue says there is not one true definition of “herb,” to her, an herb is a plant that is useful in some way. From a historical perspective, many plants came to be known as herbs because they were used medicinally. Sue encourages “herb exploration” in your garden to get a greater understanding and appreciation for what constitutes an herb.
The term “herb” is not synonymous with a herbaceous plant, which is green and soft — rather than woody — and dies to the ground in winter. Though many herbs come from herbaceous plants, others herbs are shrubs or trees, like witch-hazel, of the genus Hamamelis; Camellia sinensis, used for brewing tea; and Calycanthus floridus, commonly known as Carolina-allspice.
The Traits That Make Herbs Easy to Grow and Use
Sue says that herbs are pretty generous, and given the right environment, they rarely struggle. Like most of the plants gardeners grow, herbs like plenty of sun and well-draining soil. Given those conditions, they should thrive. As Sue puts it, herbs are generous with their growth.
Some herbs will truly take care of themselves once put in the ground, like mint and oregano, which send out runners under the soil to spread all over the garden. In fact, mint and oregano can be aggressive growers, overtaking other plants — which is one of the reasons they are better suited to container gardens.
I like herbs because you don’t need to plant a lot to yield what you need, and you only need to cut off a tiny bit each time to use an herb. And if you have ever grown herbs before, you know that fresh herbs beat store-bought 100% of the time. Sue points out that the more pungent herbs, like rosemary, sage and thyme, have flavor that goes a long way.
Rosemary is an example of a hardy herb plant that produces for years and thrives on neglect. Another is lavender, which prefers rocky soil and abundant hot sun, and will do well in a spot where other plants fail.
Pungent herbs are also deer resistant due to their strong fragrance and flavor. Insect pests rarely bother herbs, and diseases are uncommon when herbs are planted in the right conditions.
The Ornamental Value of Herbs
The foliage of herbs alone is quite striking, and when they flower, herbs attract an array of beautiful pollinators to the garden, from bees and butterflies to hummingbirds.
Purple sage is one herb that’s just gorgeous, Sue says. And variegated thyme, spilling out of a pot, can be quite dramatic.
Sue points out that flowers come and go, but herb foliage “rocks it” throughout the year.
Medicinal and Other Benefits of Herbs
Herbs have countless medicinal applications, some that we all know quite well. Mint, for example, is stimulating. On the skin, mint will create a tingling sensation and bring blood to the surface of the skin. She explains that’s why mint is used as a soap and shampoo ingredient — to give your skin a wake-up. The smell of peppermint can also provide an afternoon pick-me-up the way a cup of coffee does.
Parsley is often used as a garnish but parsley-infused water is a “super healer” for bug bites and irritated skin, Sue says.
Chamomile has antifungal properties that can help out gardeners when starting seeds. The daisy-like plant used in herbal tea can stop damping off disease from killing seedlings. Sue explains that a chamomile infusion sprayed on seedlings helps to prevent damping off by controlling the fungus that causes it.
Why Herbs Are Easily Adaptable for Containers
The top reason why herbs do so well when grown in containers is that they appreciate really good drainage, Sue says. The soil should be moist like a wrung-out sponge, and never soggy. (Some herbs, like lavender, prefer that the soil dries out completely between waterings.) Containers with adequate drainage holes often drain better and faster than in-ground or raised planting beds, and should be watered more often.
Whenever the topic of containers and drainage comes up, I like to take the opportunity to bust the myth that rocks should be put in the bottom of a container to improve drainage. The fact is, it simply doesn’t work. The water will pool in the soil above the rocks instead of getting down to the drain hole. Sue says the soil often becomes waterlogged, which can kill plants, especially Mediterranean herbs such as sage and thyme.
The Importance of Using the Right Soil in Containers
Containers require much lighter soil than the soil used in raised bed or in-ground gardens, and there are other considerations as well. There is no place for a plant in a container to reach out for nutrients, so you, the gardener, become the sole nutrient giver and soil provider, Sue says.
Look for good quality potting soil with compost or worm castings for organic material and fertility, and either perlite or vermiculite for improved aeration and drainage.
Sue experimented with cheap bags of potting soil versus potting soil from trusted brands. What she found is they often appear the same upfront — fluffy soil that looks like coffee grounds — but within a few months, the cheap soil becomes hard as a brick. And then there are the differences we can’t see, like the nutrient content.
When browsing a garden center for soil to add to your containers, don’t just reach for garden soil. Straight garden soil is too heavy for containers and will easily become compacted. A “container mix” or “potting mix,” by design, is lighter.
For those who have the space and resources to make their own potting soil, Sue offers this recipe: one part sterile garden soil, one part peat moss or coir, one part perlite or vermiculite, and one part compost. The compost — either homemade or purchased — will be the “feeder” that provides the nutrients, Sue says.
Choosing the Right Pot for Herbs
The type of pot you choose for a plant can really make a difference. So how do you decide when to use terracotta, stone or plastic?
Terracotta is suited to herbs because the porous clay allows for air exchange and for the root system to drain well. Plastic, on the other hand, can work, but it will not offer the benefits of moisture and air exchange.
Don’t rule out the beautiful stone pot you already own when designing your container herb garden, but keep in mind that it should be watered less frequently than a terracotta pot.
How to Age Terracotta Pots
Sue says, ultimately, we want our pots to look nice in our garden. If we want color, that often means a ceramic pot or plastic pot. However, Sue prefers terracotta pots, and her book explains how to make the pots look aged.
One method is to dab on paint to create a weathered look. To get a mossy pot, Sue says to put buttermilk on the terracotta, smear it with moss, and then let it sit in a shady spot. A pot left in a moist, dark spot can also attract algae, to give the pot some visual interest and color.
Growing Herbs Indoors
The best place for an herb plant growing indoors is a south-facing window, but not everyone has such a suitable spot. For supplemental light, Sue uses regular floor lamps with grow bulbs in them.
Adequate light will make for more vigorous growth and stronger plants. Plants that are far from a light source will often grow leggy in search of more light and will have a hard time adapted to direct sunlight when moved outdoors.
Moving Herbs from Indoors to Outdoors
Herbs overwintered indoors are pampered, with even temperatures and water when needed. Taking these plants outside will shock them if they are not slowly acclimated to outdoor conditions, i.e. heat, cold, wind and direct sunlight.
To move herbs outdoors, follow the same process that’s used for hardening off seedlings. On day one, move plants outdoors for an hour or less, and then back inside. Over the next one to two weeks, gradually increase the time the plants are left outdoors until they are ready to remain outdoors for the season.
Herb Pests & Diseases
The same pungent aromas that repel deer are “bug chasers” as well, Sue says. However, a few bug issues on herbs can arise from time to time.
Whitefly or aphids on basil can be quickly resolved with a sharp spray of water to knock them off.
Fungal diseases can occur when a plant lacks good drainage and airflow. Sue says that, in the case of lavender when moisture is captured between the plant and the soil surface, a white rock or piece of beach glass on top of the soil can break the moisture cycle and keep the plant drier around the base.
Sue does not treat plants with any chemicals, knowing that the herbs will be eaten or used on skin.
Mint, oregano and lemon balm will grow to fill a container in just one season. Sue recommends taking the plant out of the pot and dividing by teasing the sections apart. The four or six divisions can then be repotted separately.
Lavender and rosemary are commonly propagated through tip cuttings placed in soil. Alternatively, cuttings can be placed in water. Mint in water, for example, will readily root. Cuttings rooted in water should eventually be planted in soil and eased into that environment as a second step before ultimately moving outdoors
I hope that my conversation with Sue Goetz piqued your interest in growing herbs. If you haven’t already listened in, you can do so now by scrolling to the top of the page and clicking the Play icon in the green bar under the page title.
What are your best practices for growing herbs? Let us know in the comments below.
Links & Resources
Some product links in this guide are affiliate links. See full disclosure below.
joegardener Online Gardening Academy™: Three popular courses on gardening fundamentals; managing pests, diseases & weeds; and seed starting!
joegardener Online Gardening Academy Master Seed Starting: Everything you need to know to start your own plants from seed — indoors and out. Relaunching January 28, 2021.
Wild Alaskan Seafood Box – Our podcast episode sponsor and Brand Partner of joegardener.com – Enter code “Joe” at checkout for two special bonuses just for our podcast listeners – 2 pounds of Dungeness crab with your first order and free scallops for the life of your subscription.
*Disclosure: Some product links in this guide are affiliate links, which means we would get a commission if you purchase. However, none of the prices of these resources have been increased to compensate us. None of the items included in this list have any bearing on any compensation being an influencing factor on their inclusion here. The selection of all items featured in this post and podcast were based solely on merit and in no way influenced by any affiliate or financial incentive, or contractual relationship. At the time of this writing, Joe Lamp’l has professional relationships with the following companies who may have products included in this post and podcast: Rain Bird, Corona Tools, Milorganite, Soil3, Exmark, and Wild Alaskan Seafood Box. These companies are either Brand Partners of joegardener.com and/or advertise on our website. However, we receive no additional compensation from the sales or promotion of their product through this guide. The inclusion of any products mentioned within this post is entirely independent and exclusive of any relationship.