Pots Of Possibility: Herbs That Thrive Indoors
 | Author:
Allison Kosto, MSU Broadwater County Extension Agent
MSU Broadwater County Extension Agent |
Pots of Possibility: Herbs that Thrive Indoors
Allison Kosto
MSU Broadwater County Extension Agent
There is something satisfying about using fresh herbs in the middle of winter when the landscape is brown and bare. To be able to pick the herbs from your own plants is even more gratifying. As our Montana growing season is ending, consider starting a winter herb garden inside so you can enjoy fresh herbs year-round. Although it is slightly more challenging than growing them outdoors, many herbs can successfully be grown indoors.
For the purpose of this article, herbs are defined as plant parts, often leaves, that are being used to flavor or season food. In addition to being a food source, indoor herbs also provide fragrant foliage and visual interest. Like other houseplants, they can also absorb carbon dioxide, increase oxygen levels, increase positive feelings, reduce sound levels, and reduce stress levels.
Some herbs grow great in containers while others struggle. Easy to grow herbs include parsley, mint, chives, basil, oregano, cilantro and thyme. Options that are a little harder to grow indoors are rosemary, sage, lemon balm and marjoram. Avoid herbs with large root systems like horseradish and fennel. If you have indoor cats and dogs, then you may also want to avoid toxic plants such tarragon.
Perennial herbs that were grown outside during the summer can be brought in for the winter such as rosemary, chives, thyme and mint. Some, such as mint and chives, benefit from a light frost before they are moved indoors, which will induce a rest period and stimulate growth. Annual or biennial herbs such as basil, parsley, cilantro and caraway can be successfully started from seeds indoors.
It’s important to choose the right container with sufficient drainage holes in the bottom and well-drained potting soil. Clay or terracotta containers work great for herbs because they are porous, which allows the soil to dry more easily between waterings.
Most home temperatures are perfect for herbs. Lighting is a much bigger issue. At a minimum, herbs need a window space that will allow them to receive at least six hours of direct sunlight each day. However, some species such as rosemary, thyme and bay laurel need 12 to 16 hours a day and it will be necessary to supplement light with a full-spectrum LED or fluorescent grow light. If plants are long and lanky, that is often a sign that they are not getting enough light.
Watering depends on the species, but in general, they would be watered when the soil is dry to the touch. Overwatering is the most common issue with houseplants, and can lead to increased disease issues, most commonly root rot. Generally, herbs don’t need much fertilizer but could benefit from light fertilizer periodically throughout the winter.
Lack of humidity can be an issue in our arid environment but is generally not a major problem for herbs. If you use a wood stove, you may have more of an issue. If you feel humidity is an issue, then spraying or misting the leaves with a water bottle on a regular basis will help.
Harvest the same as you would outdoor herbs. Most herbs can handle periodic snipping and often have the best flavor right before flowering. Some leafy herbs like basil, chervil and parsley can even be cut back severely. For the mint family, including basil, cut on the stem right above a set of leaves. This will promote growth and result in a bushier plant. For perennial herbs such as chives, oregano and thyme, only remove one-third of the top growth if you plan to move them outdoors for the summer.
Perennial plants can be moved outdoors when the threat of frost has passed. You will need to slowly acclimate them back to the outdoors to more intense light and wind. Start by placing the pots in partial shade for a few hours a day. Gradually increase the duration outside and the amount of sunlight until they are fully accumulated. For annual plants, once they have flowered, they are usually coming to the end of their life. The flavor may change, often less favorable.
I hope you enjoy your fresh winter herbs! For more information about herbs or gardening in general, contact the MSU Extension Office in Broadwater County at 406-266-9242 or allison.kosto@montana.edu.
