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Garden indoors through the winter with potted herbs

Diana C. Kirby
Special to the American-Statesman
Herbs like this rosemary will brighten bookcases in sunny rooms.

The joy of gardening doesn’t have to end as we anticipate the arrival of winter. If you don’t have an outdoor vegetable bed, or you don’t like gardening in the cold, you can grow herbs indoors to use in cooking or flower bouquets all winter long.

What to grow

The easiest herbs to grow indoors include:

Basil

Bay laurel

Chives

Cilantro

Lemon balm

Mint

Parsley

Oregano

Rosemary

Sage

Tarragon

Thyme

Provide enough light

Successfully growing herbs indoors requires a lot of sun or specially made grow lights. Most herbs like up to six hours of sunlight a day.

To use natural light, find the areas in your home that get the most sunlight. Windows facing south provide the brightest light and work well for basil, bay laurel, oregano and thyme. Chives, mint and parsley will appreciate east or west windows.

Widely available, full-spectrum grow lights and kits with both lights and shelving make raising and caring for larger volumes of plants much easier and provide a consistent amount of light. Reliable light can help substantially if we have a long, gray winter with less sunny days.

You’ll know your plants need more light if they get tall and spindly with weak stems. Their leaves might also start to turn yellow or fade.

Standard lightbulbs most of us have in our homes in lamps or pendants will not provide enough light output for these plants, even though they might be OK for some traditional houseplants with lower light needs.

How to plant

For plants that thrive in Mediterranean climates like rosemary, thyme, oregano or bay laurel, you’ll want to create a blend of both potting soil and a fast-draining mix like cactus soil. These plants don’t like wet “feet” (roots). That’s why they do particularly well outdoors through our worst heat and drought. They will need similar, drier conditions indoors as well.

Use standard potting soil for other herbs, watering regularly and keeping them slightly moist but not soggy. Do not use soil labeled as garden soil, which is designed specifically for outdoor use.

Avoid overcrowding and promote good air circulation by growing only one herb per pot. While cute, little kits and troughs for growing an entire herb garden in one small container can be a recipe for disaster.

Be sure your pot has a hole in the bottom for drainage. Simply putting pebbles in the bottom or convincing yourself you just won't water too much won’t work. If you want to use a decorative planter with no hole, just slip a plastic pot with a hole inside of it. Terracotta pots wick water away from plants and work particularly well to prevent overwatering. Glazed and ceramic containers hold water better if your plants are drying out too fast.

In winter, indoor heating lowers humidity inside our homes, so get a little spray bottle and mist your plants a few times a week.

Fertilize

Indoor plants in small pots lose their nutrients quickly and need periodic fertilizer. Regular applications of all-purpose products provide vital micronutrients and nitrogen. Follow directions on the label and fertilize lightly. Over-fertilizing can kill plants or may produce larger plants with less flavor and aroma. In winter, monthly fertilizing likely will be sufficient.

If you see a white ring develop around your pots, place them in the sink and water gently until it comes out of the bottom of the pot to flush out the salt buildup that comes from fertilizer.

Harvest

Regular harvesting is as important as regular watering. In addition to encouraging new growth, it also promotes more air circulation as the plant grows. Let your plants get established, about 4 inches to 6 inches tall, before harvesting. Don't remove more than one-third of your plant’s leaves at a time.

Don't wrangle the stems by hand when you harvest your herbs. Cut with sharp shears or scissors to make clean, quick-healing cuts for your plant. Prune from the outside to encourage fuller, bushier plants. Smaller leaves are generally tastier than older, larger leaves.

If you begin to see bloom buds form, cut them off. Allowing them to grow means you will have less leaf production as the plant will turn its energy to reproduction.

Drying and freezing

If you have an abundant harvest, you can dry or freeze herbs to enjoy them for an extended time.

Dried herbs last longer and provide concentrated flavor in recipes. And, you only need to use one-fourth to one-third of the amount of fresh herbs required.

Remove any dead leaves or stems and then wash the harvested herbs and gently pat them very dry on paper towels. Tie them in bunches and hang them in a warm, dry, well-ventilated area out of the sun. You also can use a food dehydrator, your oven or your microwave.

To freeze herbs for use in cooking, wash and gently dry herbs, chop coarsely and place them in ice cube trays filled with water. Once frozen, remove cubes and place in sealed freezer bags. Take out cubes to use as needed.

Landscape Designer Diana Kirby helps garden lovers by educating, designing and installing successful gardens. Follow her at dianasdesignsaustin.com, Diana’s Designs on Facebook or dianasdesignsaustin on Instagram.

Grow parsley inside throughout the season for garnish and flavoring favorite winter recipes.