As you peruse the seed catalogs and plan your garden for 2022, keep the herbs in mind. There is sage advice that gardeners must plant native plants to support pollinators. While that is not bad advice, I have noticed that the culinary herbs I grow in my Virginia garden, the majority of which are not native to this country, attract bees, butterflies, and moths.
I have a few native herbs such as bee balm (Monarda) and hyssop (Agastache), which I grow for tea and edible flowers. But most of my culinary herbs, my garden staples, originate from abroad. Rosemary and lavender are from the Mediterranean area, lovage and salad burnet are from Europe, and oregano and savory are from the Middle East.
Many of my non-native herbs are grown for their flowers: borage, pineapple sage, calendula, nasturtiums, angelica, chamomile, chives, violets, and scented geraniums to name a few. Pollinators, including hummingbirds, love the flowers.
To me, there is ample evidence that herbs support pollinators, yet herbs are rarely mentioned in the conversation about increasing biodiversity, creating supportive ecosystems, and protecting pollinators. Herbs are not mentioned as often as native plants, but any gardener will bear witness to the bees swarming over the oregano, the butterflies crowding around the lavender, the moths flitting across the lemon balm flowers, and the caterpillars consuming fennel and parsley.
What I have come to realize is that in addition to having an herb garden, I have a “pollinator friendly” garden. Not because I purposely plant “native plants,” but because my herbs provide food and habitats. I do not spray chemicals and I do not knowingly purchase invasive plants.
In an AP News article entitled “Want to help bees? Plant flowering herbs,” writer Dean Fosdick quotes Francis Drummond, a professor of insect ecology and insect pest management at the University of Maine. Dr. Drummond said herbs appeal to a great variety of bee species. It is the abundant nectar that brings the bees in and some of the most attractive herbs to bees are thyme, comfrey, borage, oregano, lemon balm, rosemary, hyssop, sage, lavender and chives. And while we use cilantro and basil for their leaves, the bees would appreciate it if we would let them flower.
Bees are not concerned with the plant’s origins; they are primarily interested in the flower structure (for its body to land and for its tongue to reach the nectar) and the level of nectar and/or pollen. And because there is a wide variety of herbs that bloom from early spring to late fall with small or large flowers to support bees with short or long tongues, herbs are an ideal plant to have in the garden. I think too that most herbs remain in “species” form. They have not been bred to have significantly altered flowers or foliage so pollinators can continue to access the flowers and enjoy the leaves.
Mt. Cuba Center recently published a study of echinacea showing that double flowered echinacea are not favored by pollinators and birds. The double flowers have a limited ability to produce pollen, nectar, and seeds. Another study with Mt. Cuba Center and Dr. Doug Tallamy of the University of Delaware demonstrated that leaf eating insects (i.e., caterpillars) consume native plant cultivars at a similar rate as their wild counterparts except for when the plants have been selected or bred for red or purple foliage. The insects find the anthocyanins distasteful.
In his book, Nature’s Best Hope: A New Approach to Conservation that Starts in Your Yard, Dr. Tallamy emphasizes the importance of supporting caterpillars as food for birds and as the larval stage of butterflies and moths. There are several herbs that support caterpillars: fennel, dill, and parsley are host plants for the Eastern black swallowtail; rue is a host plant for the giant swallowtail and anise swallowtail; spicebush and sassafras for the spicebush swallowtail; and nettles and hops for the red admiral. I purposely grow dill, parsley, and fennel in my garden for the distinctive yellow and black banded Eastern black swallowtail caterpillars. Some for me and some for them.
Dr. Tallamy also discusses the importance of ecologically productive plants. He says that it used to be that the metric when selecting a plant was “is the plant a native or not?” but now the metric is “is the plant ecologically productive and how much insect life does the plant support?” A home gardener like me can have 30 percent or less non-native, non-invasive plants and still have a sustainable ecosystem that supports caterpillars. Interestingly, I find that as I add herbal shrubs to my garden, they tend to be native. For me, the remaining 70 percent may begin to consist of New Jersey tea, spicebush, elderberry, blackberries, and raspberries.
What I really like is the concept of ecological significance. Dr. Tallamy says: “Every square inch of planet earth has ecological significance, even where we live, work and play.” I consider my garden to have a high level of ecological significance because I am consciously supporting pollinators and increasing biodiversity through all my herbs, native and not, and through my gardening practices.
You can’t go wrong with planting herbs in your garden. If you do not use them in the kitchen, let them flourish, flower, and feed the pollinators (and the seeds will feed the birds). Adding more herbs increases biodiversity in the garden which improves garden “health” and the ability to resist stresses.