Best Perennial Herbs That You Can Grow
Agastache Anise Hyssop
This perennial herb is attractive enough to warrant adding it to the landscape for its appearance alone. The indigo purple flower spikes appear in mid-summer and are a perfect foil for hot colours or as a companion to pinks or white. They also reliably attract pollinators such as honey bees and are butterfly magnets.
From a herbal standpoint, they are appreciated for the anise/mint fragrance of the foliage and flowers as well as the leaves can be brewed, either alone or in a blend, as a refreshing herbal tea. Blue Fortune has proven to be a vigorous, reliable plant here in Ottawa, as has the yellow leafed ‘Golden Jubilee’ and both enjoy a sunny location with moderate to rich soil.
Monarda spp Bee Balm or Bergamot
This is possibly the showiest member of the extended mint family. The flower heads, which have been described as pompons or fireworks, come in a range of colours from intense purple through red to mauve, and occasionally in white.
They prefer a lightly shaded location and rich soil, but are hardy plants that will grow in a variety of locations. Being related to mint it is not surprising that this plant has a tendency to travel. I grow several patches of this at a friend’s property and we divide all of the patches in half each year in either the spring or fall.
Many varieties are susceptible to mildew, so look for ‘Mildew Resistant’ on the tag when selecting a variety for your garden. The most resistant variety that I have tried myself is ‘Petite Delight’ which is a dwarf selection with vibrant purple blooms.
Levisticum officinale Lovage
Big and bold in both the garden and the kitchen, you might want to try this pushy herb in a planter for a season before introducing it to your flower bed. It reaches over 5′ in height once mature and it has a tendency to spread out to a similar width, or further if allowed.
The leaves are useful in flavouring soups and stocks and are recommended for use in spicy dishes. The flavour is reminiscent of celery and parsley with spicy undertones. It thrives in the sun and prefers medium to rich soil.
Mentha spp Mint
Valued for its flavourful and fragrant foliage this herb is one of the most invasive perennials that you are likely to come across. I would not recommend planting this in the garden, even enclosed in a sunken pot, since it has the ability to root where stems touch the soil and escape its enclosure that way.
On the other hand, it is quite hardy and I have successfully wintered it on a planter on a balcony several times. Chocolate mint, spearmint, peppermint, and lime mint are among my favourite varieties based on their flavour, but choose your own favourites by lightly bruising the leaves of prospective purchases and checking their scent. It prefers a sunny or lightly shaded location and rich, moist soil but will tolerate a wide range of growing conditions.
Read More: Plants Not to Add to Your Garden
Origanum spp Oregano
This sprawling herb comes in a few different types, most of which have a tendency to spread aggressively. Check prospective plants for scent and flavour since many seed-grown or ornamental varieties are sadly lacking in both.
The golden leaf variety can be an attractive groundcover or addition to a herb planter but is not often of much culinary use. All oregano will thrive in the sun in most soil conditions, and all but the gold variety will tolerate half-day shade.
With their variable flavour in mind, I would suggest purchasing plants rather than starting oregano from seed to ensure that you end up with a useful plant.
Nepeta spp Catnip
While it can be used in tea, this herb is more often grown for feline consumption than humans. It has a tendency to spread, both by root and seed, but in my experience, it is not too hard to keep in check. It has naturalized in much of Ontario, so, before purchasing any check to see if you have already been weeding it out of your garden. It seems inclined to grow in both sun and shade
and will tolerate a wide range of soil types, but if you are adding it to your garden I would suggest a spot either in the sun or light shade with average soil.
Allium schoenoprasum Chives and Allium tuberosum Garlic Chives
These pretty little members of the onion family have blooms and foliage that are both edible and decorative. Chives have tall thin leaves which are hollow in the centre like regular onions and have purple blooms that look like clover flowers. Garlic Chives have flat leaves, like very tender grass, and have white flowers in rounded umbels.
Both types grow well in full sun, but I have found that they produce more tender leaves if planted in a lightly shaded location. Chives are easy to find as small plants and they can be grown from seed, but don’t expect a harvest from seedlings for at least one year. Garlic chives are sometimes a bit harder to find, but I found some at The Herb indoor Garden in Almonte and I believe that Gardens Nursery carries it in the spring.
Lavendula spp Lavender
I have been pleasantly surprised as to how hardy lavender has proven to be here in Ottawa. Our fairly consistent winter temperatures and snow cover seem to keep lavender happier here than in some warmer areas of Ontario. If it is provided with excellent drainage and a bright sunny location lavender will thrive with little additional care.
As with many of the Mediterranean herbs, overly rich soil will lead to soft, floppy growth and few blooms. Be sure to look for English lavender varieties, as the French and Spanish varieties that are starting to appear in garden centres are best treated as annuals. The flowers and foliage are both scented and dry easily if hung in small bunches in a warm area for a few days.
Melissa officinalis Lemon Balm
This lemony herb is most often blended with mint or other herbs and brewed into a summer tea. The leaves are best used fresh, as they lose much of their flavour when dried. The leaves are glossy green and the rather plain blooms are off white.
A hardy perennial with a bit of a tendency to spread, plant it in the sun or moderate shade and it will be more than happy with most soil types. I would suggest sharing the faded blooms off of plants to discourage seedlings from popping up all over the garden. I have grown this both from transplants and from seed and have not had any problems with either method.
Salvia officinalis Sage
Silvery leaved sage likes hot sunny locations with good drainage. The woody stocks of this perennial herb should not be cut back in the spring until you see the new leaves begin to poke out along the stems, looking like little white dots.
Trim back any lanky or awkward growth, but not so far back that you remove more than about half of the height of the plant, and never so far as to remove all of the leaf buds. I use the pungent, slightly bitter leaves in autumn cooking, especially with roasted squash or sweet potato soup.
The soft purple flowers are surprisingly sweet and make a lovely topping on leafy salads in the summer. Easy to grow, both from transplants and from seed, this herb is decorative enough to incorporate in the flower garden.
For the kitchen look for a large-leaved, upright variety, or select one based on the scent of the foliage. For decorative use, the creeping and silver or gold variegated varieties are far more popular. Among the creeping varieties, I am particularly fond of are the tiny ‘Elfin’ thyme that reaches a height of 1-2cm and the Woolly thyme that has fuzzy grey leaves.
All thymes prefer sunny locations and require good drainage to thrive. If you find that it becomes patchy every winter try top dressing the area that you have dedicated to thyme with ½'” to 1″ of coarse sand or fine grit to keep the leaves and stems up off of the damp soil. The decorative varieties are available from most nurseries that sell perennials. Check in the herb section for the culinary selections.