Why grow herbs?

This week, we joined Master Gardener Susie Everding to talk about herbs, a sometimes overlooked addition to the edible garden. While herbs are usually valued for their culinary contributions or for medicinal purposes, they also make great ornamentals and many attract pollinators. 

Basil and thyme. Sabine Kroschel on Pixabay

Herbs are generally undemanding plants. They prefer full sun (6 or more hours/day), well drained soil, and have modest watering and nutrient requirements.  Greater sun exposure, results in increased oil production within plant foliage and stems, leading to stronger flavours and fragrance. 

A little goes a long way when planting herbs. For most of us, a single plant of each type will provide a season’s worth of flavourings.

Herbs as ornamentals

Beyond flavour, herbs can be striking ornamentals, with their varied foliage colours, textures and shapes: think of feathery dill, variegated sages or purple basil, curly parsley, tiny leaves of thyme or the spiky blades of lemongrass.  If allowed to flower, the blossoms too can be beautiful.

Image credit: Gardener’s Path

Location

Herbs can planted wherever their growth requirements will be met. Those planted near the kitchen door are handy for use in everyday cooking. As ornamentals or for their fragrance, they may be suited to a the edges of a pathway or perhaps in the front yard to enchant passersby.

Herbs are an excellent choice for containers either planted singly or with multiple types in a single pot. For aggressive spreaders such as mint, container planting will restrict their tendency to swarm over the garden.  As with any container plant, use a good quality potting soil, with adequate watering and nutrient supplementation. For tips, check out our previous article on container gardening

Pests and diseases

The strong aroma of many herbs seems unappealing to deer and other mammals that are usually fond of nibbling garden vegetables. Insect and disease problems are rare, and good cultural practices (airflow between plants, good soil drainage) reduces the likelihood of a problem. Should whiteflies or aphids visit, simply spray them off with a jet of water from the hose.

Pollinators and host plants

Some herbs are host plants for beneficial insects. When allowed to flower, dill, fennel and parsley are a magnet for swallowtail butterflies.

Flowers are both a nectar and pollen source for insects such as bees and butterflies. But did you know that they support such lesser known pollinators as lacewings, syrphid flies, tachinid flies, minute pirate bugs, soldier beetles and others? Many of these insects feed on the nectar and pollen as adults but in their larval form, they will munch on pests afflicting neighbouring plants. 

Herbs can also limit egg-laying of insect pests. For example dill, sage and thyme deter cabbage butterflies from laying their eggs on brassicas such as broccoli. Basil planted with tomatoes can deter hornworm moths from laying.

What to plant

As with other vegetable garden choices, plant what you like to eat as well as those that support pollinator species.  Be amazed at the flavour difference when fresh herbs are harvested directly from your garden. 

Susie’s favourites include:

  • Basil – easy to grow from seed, Susie starts hers indoors at the end of March for transplanting at the end of May, after the risk of frost has passed. Cutting back by a third will stimulate side shoots and a bushier form. Pesto lovers will want to plant more than one!
  • Cilantro – while not a flavour enjoyed by everyone, this is a fast growing (and flowering) herb that can be direct sown every few weeks for a summer long harvest. If allowed to go to seed in fall, watch for volunteers in the fall
  • Dill – Dill is an easy to grow annual which  readily self seeds.  Watch for flowers in hot weather/ The nectar feeds flies, lady bugs, damsel bugs, and many small bee species 
  • Mint – whether for mint sauce with lamb, or in a classic mint julep, this one smells gorgeous. We suggest growing it in a contained area to avoid rampant spread via underground rhizomes
  • Oregano – the pairing of Greek oregano and tomatoes is a classic. This perennial over-winters in our area, so you only need plant it once!
  • Thyme – Along with oregano, thyme is useful to the insects that you want in your garden for their nectar and pollen, but their shape creates the ideal habitat for ground-dwelling creatures like spiders and beetles too.
  • Lemongrass – growing in full sun to part shade, lemon scented lemongrass is a magnificent herb that grows up to one metre in height. While it is easy to start from seed, or root in water from stems purchased at the grocery store. The swollen, white, lower end of the stem is used in teas and Asian cuisine, but it is also a lovely ornamental 
  • Lovage – the upright form of lovage grows tall enough (1-2m) to  act as a visual barrier. Similar to celery leaves in appearance, but with a stronger flavour, they are among the first plants to harvest in spring. The stems apparently make a great straw for Bloody Marys
  • Parsley – start indoors from seed in early March, as the seeds are slow to germinate. As a biennial, it will produce leaves in the first year and flowers the next but it’s hard to overwinter in our area unless it’s well-protected.  Grow lots if you like tabbouleh !
  • Rosemary – start from seed or from a cutting, or for the impatient gardener, purchase a plant.  This perennial is not hardy in our zone, but will live happily in the garden from the end of May until early October, at which point it can be dug up and brought indoors. While it won’t thrive during the darker days of winter, simply leave it alone (no fertilizer, water only if the soil is dry and harvest minimally) . Come May, it can head back outdoors (re-pot if needed)
  • Sage – This  small perennial has broad oval, gray-green leaves that are used to flavour soups, stews, and poultry stuffing. It is a revelation for the taste buds when pan fried and liberally added to potatoes and gravy. 
  • French tarragon – a perennial that does not set viable seed, so propagation is via root division or stem cuttings. It has beautiful, glossy green leaves and responds well to cutting back in mid-season to restore the foliage. In Susie’s  opinion, tarragon with roasted beets is a match made in heaven.