University of Vermont Extension 
Department of Plant and Soil Science

Summer News Article
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THE HERBAL HARVEST


Dr. Leonard Perry, Extension Professor
University of Vermont
 
An herb is any plant that is used in whole or part as an ingredient for flavor or fragrance. To get the most out of herbs, harvest them at their peak of freshness and store or preserve them properly.

Harvest herbs when the oils responsible for flavor and aroma are at their peak. The timing depends on what plant part is being harvested and its intended use.   Most herbs are cultivated for their foliage and should be harvested just before the flower buds open.   Although herbs such as chives are quite attractive in bloom, flowering can cause the foliage to develop an off-flavor.

In general the best time to harvest for maximum flavor is in early morning.  Avoid bruising leaves, and avoid leaving them in the sun where they’ll start to lose their oils.   Rinse in cold water, then shake gently to remove some moisture.  Remove any diseased or wilted plant parts.

Many herbs, especially parsley, chives, mint, and oregano, can be harvested continually for fresh use beginning as soon as the plant has enough foliage to sustain growth. Harvest herbs grown for seeds-- dill, caraway, coriander, and cumin, for example-- as the fruits change color from green to brown or gray but before they scatter to the ground.

Collect herb flowers such as borage and chamomile just before full flowering. Harvest herb roots including bloodroot, chicory, ginseng, and golden seal in the fall, after the foliage fades. Just be sure to mark the plants before the foliage drops, so you don't forget where they are located. You can harvest fragrant herbs and dry them for potpourri.

If you don't intend to use herbs immediately, drying is the most common way to preserve them. Tie leafy herbs with long stems in bunches and hang to air dry.  Easiest to dry this way are the sturdy herbs such as rosemary, sage, thyme, summer savory, and parsley.  Rinse dust and soil from foliage, shake off excess water, and remove dead or damaged leaves. Then hang upside down in a warm, dry, well-ventilated place. To preserve foliage color, avoid drying in sunlight. Enclose seed heads in paper bags to catch seeds as they fall. Or you can horizontal on dry on wire mesh trays in well-ventilated areas. 

If you have a dehydrator (useful too for fruits and vegetables), this is a quick and easy method for drying.  It is useful for high-moisture herbs such as basil, oregano, tarragon, lemon balms, and mints.  If these aren’t dried quickly they may mold.  Use a low dehydrator setting, between 95 and 115 degrees (F) is ideal, slightly higher if the air is humid.  Wash and shake as you would if air drying, then place in single layers on trays.  Depending on the herb, it may dry in as soon as one to 4 hours, but usually within 12 hours.  Check periodically, and remove when leaves crumble when touched and stems break when bent.

An old-fashioned method of preservation is to salt-cure by placing herbs between layers of coarse grade or regular table salt. Seal the drying salt in an airtight container such as a glass jar or plastic tub. Salt-drying preserves herbs for future use as well as produces herb-flavored salt that can be used as a seasoning in cooking.

When dried, leaves may be stored whole or crumbled.  Store in airtight and dry containers in cool and dark.  Remember that dried herbs are 3 to 4 times stronger than if fresh, so use proportionately less in recipes.
 
Cut flower heads of thyme when 4 to 6 inches long and at full bloom.  Use dried thyme in soups, stews, sauces, dressings, and to flavor meats.  The relatively larger leaves of sage are best cut before or during bloom.  Dried sage leaves are often used with meats and sausage.  Fresh mint leaves are known by many as a flavoring for iced drinks, but dried they flavor tea, sauces such as for lamb, and fruit salads. 

Parsley can be cut as soon as plants are 4 to 6 inches tall, and may continue through the season.  Then you can dig the plants, pot, and grow in a sunny location indoors through fall and into winter.  Fresh or dried, parsley is used in many ways, particularly in Italian cooking and sauses.

Chives are another common herb that has many uses, can be cut continually, then potted and brought indoors for winter.  It is also a hardy perennial out of doors.  Not only do the flowers lessen the flavor, but if they form seeds you’ll have chives seeded all around.  They give a mild onion flavor to many recipes, and are especially favored with eggs and cottage cheese.

Harvest marjoram leaves and flowers either just before bloom or when beginning to bloom.  Use marjoram either fresh or dried to flavor soups, egg or potato recipes, and meats.

You can use dill leaves or flowers to flavor soups and fish (it’s a great addition to tuna fish sandwiches).  It can be boiled with cabbage, cauliflower, or turnips.  If using the seeds to flavor dill pickles, harvest when they are fully developed but still green.

More on harvesting and preserving all types of crops can be found online from the National Center for Home Food Preservation (www.ugs.edu/nchfp/). 

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