Sage advice

6 tips for cultivating herbs indoors

Find this article in A/J’s Night Issue!

FRESH HERBS are a wonderful addition to salads, soups and dishes of all kinds. Growing your favourites at home is inexpensive and convenient, but does require a little TLC. We asked a trio of Canadian gardening experts for their top indoor growing tips.

1. Let there be light
“Most of our favourite culinary herbs are native to the Mediterranean, where they grow in bright sunlight, in rocky, well-drained soil,” explains Stephen Westcott-Gratton, senior horticultural editor of Canadian Gardening Magazine. “The challenge is to mimic these conditions as much as possible indoors.”

Herbs need six to eight hours of sunlight a day. This can be tricky in winter, when the days are short and light intensity is low. Ideal placement for an herb garden is next to an unobstructed south-facing window, or a west-facing one as a second choice; a window that faces north is unlikely to provide enough light.

If your living space doesn’t have a good location, Westcott-Gratton recommends growing more shade-tolerant herbs, such as mint, perilla, lemon balm or parsley. Or you can try growing sprouts on your kitchen counter. “Herb seeds such as caraway, fennel, fenugreek, garlic chives and mustards all make A-one sprouts, and have a distinctive herby flavour,” says Westcott-Gratton.

2. Choose wisely
In addition to choosing herbs that grow well indoors with limited light, look for those that need little space. Gardening guru Mark Cullen recommends basil, parsley, oregano, thyme, rosemary and lavender.

Research the care for each herb as well – Westcott-Gratton advises that certain herbs (such as basil, chives, oregano, summer savory and cumin) are easier for novice gardeners, while others (garlic, bay tree, chili peppers, sage and French tarragon) are more challenging. Tip: buy seedlings instead of seeds to get growing more easily.

3. Don’t drown your plants
More houseplants are killed by kindness than neglect. Cullen says “most problems with indoor plants originate with over-watering,” and offers this advice: allow the top one to two centimetres of soil to dry before watering again. Westcott-Gratton recommends watering herbs thoroughly (so that water comes out the drainage holes) and then leaving them to dry for up to 14 days. He says the symptoms of over- and under-watering are similar (weak growth, leaf drop, yellowing and browning edges), but overdoing it is usually the culprit.

Be careful about misting herbs. Westcott-Gratton warns that woody plants like lavender and rosemary can quickly develop mildew. Instead, place woody herbs in a sunny bathroom or kitchen window for humidity.

4. Pick the right pot
Almost any kind will work, so get creative! That said, terra cotta is preferable to plastic – it’s permeable, so moisture and air can flow into the soil. It’s best to soak empty terra cotta pots in water for two to three hours before use, so they don’t absorb all the moisture when you add the herbs. Whether made of terra cotta, coconut fibre, ceramics or another material, herb pots must also have drainage holes; stick a drip saucer underneath and discard excess water promptly to prevent root rot. 

5. Happy soil = happy plants
Soil with good drainage is a must. Create your own basic mix with two parts packaged potting soil, one part coarse sand and one part peat moss. Or try this idea from Gayla Trail, author and creator of the gardening project You Grow Girl: mix regular potting soil with soil made for cacti and succulents – most culinary herbs will appreciate the extra drainage. Don’t bring in soil from outdoors, which contains organisms that aren’t used to indoor growing conditions.

Year-round indoor plants will need fertilizer during growing season. Organic options include vermicompost (worm castings), a little bit of sea kelp or, if you’re desperate, fish emulsion (plug your nose). However, there’s no need to fertilize plants under low-light conditions. “The good news about culinary herbs is that many of them grow well and produce the best flavour when soil fertility is not high,” says Trail.

6. Savour your labour
Don’t forget to use your herbs! Cutting the plants encourages growth – just don’t cut off more than a third at a time.