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Gardening: Get Good At It

Growing Herbs Indoors

October 11, 2016

Herbs make a great addition to a garden, but they can also be grown indoors as year-round houseplants or just during the winter months. Herbs grown indoors offer many benefits including fragrant foliage and a constant supply of herb leaves for cooking. They may even cure those winter garden blues when it’s cold outside.

Most herbs are in two or more categories.

Aromatic herbs have pleasant smelling flowers or foliage and are grown for their oils to produce perfumes and various scents. Lavender, mint and rosemary are examples.

Culinary herbs are prized for adding flavor to cooking. Among these herbs are parsley, sage, basil and chives just to name a few.

Other categories include medicinal and ornamental. I will not cover these now but a list will be on our website along with a list of resources.

First, not all herbs will grow well indoors because of their root systems but there are seven drought-tolerant herbs for easy kitchen container gardening: parsley, chives, rosemary, thyme, sage, marjoram and winter savory.

The most important fact is that herbs need six hours of direct sunlight. Herbs can be placed in a sunny location such as a window with southern exposure. It’s important to realize that the intensity of winter light is often less than one-tenth of the outdoor light during summer. Window glass further decreases the amount of light that’s available. It may be necessary to rotate pots often so that each side gets enough light for uniform growth.

You might consider placing your herbs 6-9 inches (above the tops of the plants) away from two 40 watt, cool white fluorescent bulbs for 14 to 16 hours. Not all herbs can tolerate indirect sunlight so I’ve included a list on our website.

Secondly, keep herbs in rooms that have at least a 65 – 70 degree day and 55 to 70 degree night. Herbs require a proper balance between a humid environment and adequate air circulation. Because we live in a high desert region we have very low humidity. An option for increasing humidity for the herbs is to set the herb containers in a pan of moist pebbles or spray plants with a misting bottle of water.

Air circulation is also important and opening a window in our winter may not be an option even on sunnier days. Just use a small fan to circulate air during the winter.

Herbs should be grown in containers with a drainage hole and in a potting mix that will aid water drainage. Water the potting mix when it starts to dry out. Herbs such as thyme, oregano and sage should dry out completely between watering while mint, rosemary and scented geranium prefer a little more moisture.

Unlike herbs that grow in the garden, potted herbs need regular feedings. Fertilize with a low dose of water-soluble fertilizer about every 3-4 weeks. Fertilizing two often may negatively affect the herb’s aroma and taste.

Lastly, if you discover pests such as white fly or aphids I suggest using a soapy solution, 1-2 tablespoons of mild dishwashing soap to one gallon of warm water. Spray the infested plants once a week while the pests are visible. Check the plants often to make certain the soap solution isn’t too strong. If the leaves become discolored, reduce the amount of soap solution. Always wash the leaves before using in a recipe.

I hope you will enjoy growing some herbs this winter. It’s fun, fairly easy and tasty. For answers to all your garden questions, visit our website: gocomga.com and click on the KPOV tab on the orange bar. This has been Gardening: Get Good At It. Thanks for listening.

Medicinal herbs: The list is numerous and The Complete Book of Herbs by Lesley Bremness contains a section titled ‘Herbs for Health’ that will answer most of your herbal questions. While present medical knowledge recognizes some herbs as having healing properties, others are highly overrated and should be used carefully, if at all, because they can interact with medications, whether it is a prescription or an over-the-counter item. Before using herbs for medicinal purposes, consult with your health care professional.

Ornamental herbs: Grown for fresh or dried arrangements, these herbs may have brightly colored flowers and foliage while others have variegated foliage. A few examples are thyme, rosemary, mint, lavender and chives.

Herbs that can tolerate indirect sunlight: Mint (Mentha spp), bay (Laurus nobilis), rosemary (Rosmarinus officinalis) and Thyme Thymus spp). Lemon balm (Melissa officinalis) and tarragon (Artemisia dracunculus) will even grow well in very low light conditions.

Resources:

Growing Herbs Indoors - Elsa S. Sanchez, (assistant professor of horticultural systems management). www.extension.psu.edu.

Start an herb garden on your kitchen windowsill this fall by Denise Ruttan. Source: Weston Miller. www.extension.oregonstate.edu/gardening/node/2296.

Growing Herbs Indoors by P. Allen Smith

The Complete Book of Herbs – A practical guide to growing and using herbs by Lesley Bremness.