Growing herbs: UW offers gardening advice for Wyoming growers

An herb is a seed plant which does not produce a woody stem like a tree but will live long enough to develop flowers and seeds.

Holding terrific attributes, herbs can be grown in cooler climates and survive Wyoming’s winters while prospering in the Cowboy State’s sunshine.

Herbs may be annuals, biennials or perennial plants, and with proper preparation and care, can be grown for culinary, aromatic, ornamental and medicinal use.

Culinary herbs are probably the most useful to gardeners, as they have a wide range of uses in the kitchen.

Deciding what to grow

Growing herbs is a rewarding hobby for many home gardeners, and many herbs can be grown in a variety of containers or in the ground.

From seed choices to deciding where to plant, UW Extension can provide answers to a variety of questions to help Wyoming gardens flourish.

“Start with what you like to eat and learn how to grow it,” suggested UW Extension Master Gardener State Coordinator Chris Hilgert. “Gardening combines science, nutrition and physical activity.”

UW Extension suggests growing a few herbs well, rather than planting too many types and not being able to grow any of them to full-flavored maturity.

“Herbs may be started by seed, propagated from cuttings, divided from existing plants or purchased as transplants,” states UW Extension Small Acreage Outreach Coordinator Jennifer Thompson.

She notes starting seeds indoors is best done in March but varies based on seed maturity dates and an area’s average last frost date. Seedlings should have at least two true leaves before transplanting into pots or a garden.

“Sow anise, cilantro, coriander and dill directly in the garden since they do not transplant well,” UW Extension Service Horticulturist Catherine Wissner advises. “Rosemary, tarragon, oregano, lemon verbena and lavender should be bought as plants.”

UW Extension reminds home gardeners to keep in mind some herbs, such as mint and dill, can quickly become weeds if they are not kept under control.

It is usually more difficult to produce top-quality seed herbs such as caraway, dill and anise than it is to produce leafy herbs. 

Some widely used culinary herbs are drought tolerant including marjoram, oregano, savory and thyme and only a few herbs, such as mint, angelica and lovage can do well in moist soils.

Herbs which do well in shade consist of catnip, chamomile, lovage, tarragon, thyme, parsley and mint.

Wissner notes, “A good list for beginners to start with includes perennials such as sage, tarragon, chives and thyme and annuals such as summer savory, marjoram and basil.”

Cultivating herbs

UW Department of Plant Sciences and Cooperative Extension Service Horticulture Specialist Karen Panter states most herbs need a sunny location with at least eight hours of sun each day, rich and well-draining soil and irrigated through a drip system.

“Herbs are also prone to fewer pests and diseases and can grow well in most garden soils without additional fertilizer,” Panter continues. “Before planting, incorporate good-quality organic matter to a depth of about six inches. Most herbs require low levels of fertilizer.”

Herbs do not like to be over-fertilized, and she suggests using slow-release fertilizer which should last all summer. 

“Heavy applications of fertilizer, especially those containing large amounts of nitrogen, will decrease the concentration of essential oils in lush green growth,” she mentions.

Plants such as chervil, fennel, lovage and summer savory require moderate amounts of fertilizer. 

Generally, highly-fertile soil tends to produce excessive amounts of foliage with poor flavor.

UW Extension notes adding several bushels of peat or a thin layer of compost per 100 square feet of garden area will help improve soil condition and retain needed moisture.

“Most herbs require consistent watering, especially early in the season when they are young, including parsley, basil, chives and mint,” Panter says. “Many require little extra water, such as thyme and sage but perennial herbs will require winter watering as well.”

Preserving herbs

“The shelf life of many herbs is one to two years, but fresh leaves may be picked as soon as the plant has enough foliage to maintain growth and to ensure good oil content. Pick leaves or seeds after dew has disappeared but before the sun becomes too hot,” Wissner states. 

“Herb leaves keep their flavor best when they are stored whole and crushed just before use, and herb seeds used for cooking should be stored whole and ground up as needed,” she adds.

Panter recommends when drying herbs to cut them just before the flowers open. At this point, the oils are most concentrated in the foliage and flavor will be maintained if stored properly.

She says, “Cut the stems in the morning, tie them together at the cut ends and hang them upside down in an airy, well-ventilated, dark area away from direct sunlight. Then strip the leaves when they are crispy and store them in airtight jars.”

Another way to dry herbs is to strip the leaves and lay them flat on screens in an airy, well-ventilated, dark area away from sunlight and store in airtight jars after they are crispy.

She adds for herbs grown for their seeds, harvest the seed heads or pods when they turn brown, dry them on paper or in paper bags until the seeds come loose, then store the seeds in airtight containers.

Wissner reminds gardeners, “Most herbs are at their peak flavor just before flowering and can be dried or frozen with a shelf life of one to two years.” 

UW Extension has great resources – publications, videos and programs – designed specifically to help Wyoming gardeners grow herbs.

Melissa Anderson is the editor of the Wyoming Livestock Roundup. Send comments on this article to roundup@wylr.net.