When you’re a laidback gardener, it’s normal to make more and more space in the garden for perennial plants: the ones that grow back each year.
Herbs are no exception. Each year, I add one or two additional species to my perennial herb collection. I’ve discovered many herbs that are not reported to be perennial, but that actually do survive in my cold climate garden (USDA zone 4). And I’ll show you a few here.
Compromise On Flavor
In many cases, there are two forms of the same herb: an annual variety and a perennial one. To my great dismay, the annual varieties are often the tastiest. Still, the perennial varieties do fulfill their mission and their extreme ease of cultivation means I certainly have no regrets having chosen to grow them in my garden.
Chives… and Egyptian Onions
It goes without saying that chives (Allium schoenoprasum) are a popular herb … and for many reasons. Very easy to grow, chives is a favorite of young and old alike. We nibble on chives first thing in spring, as they emerge from the ground early. And as for hardiness, you could scarcely do better. They can survive in USDA hardiness zones 2 to 9 without flinching. It’s also a herb that I recommend trying in large containers or raised beds, even in USDA zone 4 or 5, because I find chives will often overwinter in containers. And, in a cold climate, container gardens become much colder than in-ground gardens.
I’d like to take this opportunity to present another perennial of the same family, the Egyptian onion (Allium × proliferum), also known as tree onion, topsetting onion, and walking onion. This curious onion produces cylindrical upright leaves in the spring. Then in summer, the flower stalk gives birth to small edible onions. Yes, right up on top. As the stems bend down to the ground under the weight of the bulbs, the little onions take root and give rise to new plants.
In my garden, I created a small clump of about 3 feet by 2 feet (90 cm × 60 cm) where I let them grow freely. In spring, I harvest and consume the leaves, which perfectly replace green onions. Then in the summer, I cook with the baby onions it produces. USDA hardiness zones 3 to 10.
Oregano is a superb mounded ball-shaped plant about 18 inches (45 cm) in height and diameter, covered with small rounded leaves. Most sources list common oregano (Origanum vulgare) as hardy to USDA zones 3 to 9. And it has certainly proved hardy for me. However, it’s not the one with the best flavor.
That would be Greek oregano (Origanum vulgare subsp. hirtum). My reference sources claim it’s just as hardy, supposedly zones 3 to 9, but in my garden, it doesn’t know that it’s even hardy to zone 4! Instead, it behaves like an annual herb and never comes back the following year.
What can I say? That’s the kind of situation all gardeners have to live with. There are plants like that. For unknown reasons, they just refuse to give us satisfaction.
You can tell the two varieties appart by the color of the flowers: pink for common oregano, and white for Greek oregano. Do be careful, though! Common oregano has very pretty blooms, but you have to deadhead (remove the spent flower stalks) quickly, as soon as the blossoms fade, to keep it from going to seed. It self-sows far too prolifically!
I really also have to mention golden oregano (Origanum vulgare ‘Aureum’), with its delightful lemon yellow leaves, also perennial and hardy in USDA hardiness zones 4 to 9. It forms a very nice low clump, about 9 inches (20 cm) in height, at the base of my tarragon, by the edge of my perennial herb border. For flavor, it really isn’t the best. But for ornamentation, it’s perfect!
Mint, Of Course, But Conditions Apply
When it comes to vigorous perennial herbs, it would be impossible to ignore mints. However, their reputation for being very invasive sometimes puts them on the black list (with good reason, I have to admit). But, when you’re a fan of tabbouleh salads—and of mojitos!—, mint is a must.
In my garden, it’s the only perennial that I don’t grow in the ground. Mine grow in a huge antique aluminum cooking pot, with a hole in the bottom, placed on a concrete slab. That way, the mint simply can’t escape, not even through the drainage holes. I placed the container in a semi-shaded location where snow accumulates in winter. Result: my mints do survive the winter there (except this last year, ‘cause, baby, it was very cold outside). Peppermint (Mentha × piperita) and spearmint (Mentha spicata) are the most successful in this context. Both grow in USDA hardiness zones 3 to 9.
French Tarragon: Dare to Try It
Surprisingly, I have a French tarragon plant (Artemisia dracunculus var. sativa) in the garden. In fact, it has been with me for almost 20 years! And I can definitely use the term “surprisingly”, because it’s reputed to not be very hardy. And also to be short-lived.
French tarragon is the one with the best taste. Its close cousin or, should we say, its imitator, Russian tarragon (Artemisia dracunculus), doesn’t even come close to the French when it comes to flavor. Now, Russian tarragon is supposed to be hardier of the two, but why opt for a poor imitation when you can have the real thing? In theory, French tarragon grows in USDA hardiness zones 5 to 9… yet it positively thrives in my zone 4 garden!
Here’s another nice surprise in my garden. But that requires a bit of an explanation:
There’s never enough dill in a garden. I love dill, but it’s an annual herb. Fennel looks a bit like it, but it’s not supposed to be hardy enough for me either. It’s adapted to USDA hardiness zones 6 to 9, so it should only grow as an annual in my zone 4 garden. However, the purple-colored selection called bronze fennel (Foeniculum vulgare ‘Purpureum’), which should also theoretically act like an annual (it too is rated for USDA hardiness zones 6 to 9) survived 6 or 7 winters in a row in my vegetable garden. So, I believe it’s hardier that people give it credit for.
Very ornamental, with its purple-brown foliage and umbels of yellow flowers, this amazing plant has a flavor that is closer to dill than that of classic fennel. I did lose it, though, but that was my fault. I tried to transplant it two winters ago and it didn’t survive the transition. But I promised myself to reintroduce bronze fennel to the garden… as soon as I manage to find a plant of it. You don’t often come across it in garden centers where I live. Not when no one locally thinks it’s hardy!
Of course, this is far from a complete list of perennial herbs to grow in the garden. Indeed, I really ought to mention common sage (Salvia officinalis), which can survive in USDA hardiness zones 5 to 9; even 4 with good snow cover. And there’s also savory (Satureja montana), many thymes (Thymus spp.) and lovage (Levisticum officinale).
All that’s missing would be a hardy basil and life would be perfect!