How to improve on the delicious aroma of a savory sauce or simmering soup wafting through the house on a cold, drizzly day?
With a pinch of fresh herbs and seasonings, of course. Your winter garden may be slumbering outdoors. But that doesn’t mean you have to give up growing. Tend a few herbs on a sunny windowsill and you’ll be able to infuse fresh flavors in your fixings throughout the shortest days of the year.
To successfully grow herbs indoors you must have light, and lots of it. Most herbs need at least six to eight hours of daily direct sunlight — or very bright indirect light — to thrive and produce oils. Your best bet is a south or southwest-facing window. Hold your hand above the sill. If your hand casts a distinct shadow, your herbs should be okay.
Otherwise, set up supplemental lighting. A dedicated grow light system consisting of a stand and one or more high-efficiency fluorescent bulbs starts at about $100. Or buy a couple of inexpensive, clamp-on aluminum reflectors from a hardware store, then fit them with compact fluorescent bulbs. Place the reflectors 4 to 6 inches from the plants. If the leaves begin to crisp up, move the lights a few inches away. If the plants stretch toward the lights, move them closer.
Also, artificial light is not as intense as natural sunlight. Put the lights on a timer and run them 12 to 16 hours a day.
Without a greenhouse, it’s difficult to start herb seed indoors, especially in winter. Instead, buy organically grown seedlings, then transplant them to containers at least 6 inches wide.
Good drainage is key. Use fresh potting soil — not dirt from the garden, which may be heavy and drain poorly. Herbs prefer soil that stays crumbly, even when you squeeze it when it’s wet. Consider adding perlite or vermiculite, or blend regular potting soil with a cactus and succulent mix.
Terra cotta pots breathe, which helps reduce the threat of fungal diseases. But with good air circulation, other decorative containers are fine, too. Just be sure to plant each type of herb in its own pot, as container-grown herbs typically don’t like to share precious soil with roots of other herbs. For instance, you can cluster several parsley plants. But don’t combine oregano with chives with mint.
Indoors or out, herbs grow at a leisurely pace during winter. It takes longer for them to build up their volatile oils and their yields are not likely to be as abundant. That said, the following eight should do well.
• Bay (Lauris nobilis) grows slowly. Fortunately, most recipes require only a few leaves. Fresh bay leaves are mild; their potency picks up a few weeks after harvest.
• Chives (Allium schoenoprasum) grow from tiny bulbs packed tightly together. They need less light than most herbs indoors, and prefer their soil a little moister.
• Lemongrass (Cymbopogon citratus) is a giant among herbs, reaching up to 6 feet tall in the garden. Indoors, that height is not likely. However, still plant your lemongrass in a larger pot, up to 16 inches in diameter.
• Mint (Mentha) is invasive in the garden and should be kept solo indoors as well, to prevent it from overrunning unsuspecting companions. Spearmint (Mentha spicata) complements meat, vegetables, fruit and chocolate, while peppermint (Mentha x piperita) is more intensely flavored and is infused to make tea.
• Parsley (Petroselinum hortense) does not need as much light. But it grows slowly. Plant several to yield more than a few sprigs.
• Oregano (Origanum vulgare) craves as much light as you can provide. Another invasive, it’s best grown alone.
• Rosemary (Rosmarinus officinalis) loves dry soil and sun. An upright-growing type — rather than a trailing variety — will conserve space. You can often find cute topiaries trained as Christmas trees over the holidays.
• Thyme (Thymus) also covets light. Fresh thyme is sweeter and less bitter than dried thyme, and comes in flavors ranging from hints of lemon to mint to caraway to oregano.
Note the conspicuous absence of basil on the list. A heat and sun-loving annual herb, it’s best in the summer garden. In addition, dill and cilantro send down deep tap roots that are difficult to keep going in all but the largest pots outdoors, much less inside. And while it’s just about unstoppable in the garden, culinary sage turns into a balky wimp indoors.
Exercise restraint when watering. Wait until the top half inch or more of soil is dry, then put the plants in a sink and run tepid water over the soil — not on the leaves — for a few minutes. Let the pots drain. Fifteen to 30 minutes later, water again, then let them drain again.
Don’t leave standing water in the saucers. Constant wet at your herbs’ roots can lead to rot. Also don’t instantly water if a few leaves turn yellow. Yellowing often indicates overwatering, so check the soil first.
Pinch the leaves regularly and snip any emerging flower buds. Harvesting the leaves will help keep your herbs bushy and promote new growth. But don’t trim more than a third at a time unless you’re willing to risk losing the entire plant.
After the first of the year, apply a liquid fertilizer. Diluted fish emulsion is often recommended, although its powerful odor can be overwhelming indoors. Alternatives include kelp and other products low in phosphorous, which will boost your herbs’ all-important foliage, rather than flowers.
This article was first published in the Winter 2012 issue of Edible Santa Barbara.
Copyright, Joan S. Bolton. All rights reserved. Reproduction of text or photos in any form is prohibited without written permission.