Q: My herb garden is growing beautifully and I have lots of stems to gather and dry. What’s the best way to harvest herbs so I capture them at their peak?
A: You are wise to plan ahead for a bountiful harvest because how herbs are handled before, during and just after they are gathered definitely affects their quality. Careful attention to details will make harvesting fast and enjoyable, and also insures that you will be able to taste and smell summer when you use your herbs for cooking, crafts or tasty teas.
Begin by bringing your plants into top condition while they are still in the ground. A week or so before you plan to pick, carefully check each plant and use a small pair of scissors to snip out any branches that show damage from insects or disease. Pick off blemished leaves, too, and use a stick to stir spider webs into oblivion.
After this pre-harvest grooming, I like to treat plants to a weak drink of organic fertilizer. Mix a water-soluble fertilizer at half the rate recommended on the package, and thoroughly soak the root zones. I pour from a plastic soda bottle to avoid getting the fertilizer on the leaves. This close to harvest time, I don’t want anything on the leaves except clean water and sunshine.
Warm sun stimulates the production of essential oils in herb leaves, especially if the plants are very slightly stressed by drought. Three days or so before you harvest, put a nozzle on your hose to provide a fine spray and gently clean the plants by washing them down at different angles. Pay particular attention to leaf undersides where dirt often accumulates. Do this in the morning if you can, so the wet foliage will have ample time to dry completely before night. Unless the soil is very dry, don’t water your herbs again until you are ready to gather the stems.
The best time of day to harvest herbs is mid to late morning, an hour or so after the dew has dried. Only a few hours into the day, the leaves and stems should be plump with moisture and not stressed to the point of wilting, as often happens by late afternoon. Harvest your herbs in small batches, keeping similar species together, and immediately bring them into a cool room or loosely wrap bundles of herbs in slightly dampened clean dishtowels and lay the rolls on a shelf in your refrigerator. This is an excellent trick to try with herbs you plan to take some time with, such as mint or artemisia for crafting into wreaths while they are fresh. Herbs that are promptly chilled after they are cut will stay in perfect condition for a couple of days, and sometimes even longer.
If you plan to share your fresh harvest with friends, plunge the cut ends of herb branches into containers of cool water, and set them to condition in a cool, dark place. This is a great use for stems that surprise you by showing more blossoms than leaves.
As long as they are cleaned thoroughly two or three days before you cut them, herbs destined for the drying rack need not be washed again. Lay the stems out on a clean surface, and sort them by size. Bundle together the longest stems with small rubber bands and hang them in a warm, airy place where they will not be exposed to direct sun. Short stems or individual leaves are easily dried in a slow oven, dehydrator or on a clean piece of window screen fitted onto a frame.
Rinse herbs you plan to freeze. Herbs that lose their flavor when dried, such as parsley, cilantro and basil, keep well when chopped, heaped into empty ice cube trays, and then covered with water before being popped into the freezer. Try the same trick with whole mint leaves, which can be frozen in cubes of apple or cranberry juice.
Don’t forget about the plants left behind in your garden, which may make a strong comeback if given a deep drink of water laced with a bit of plant food. Many herbs will grow a fast flush of leaves at the tail end of the growing season.
Barbara Pleasant is a contributing editor to The Herb Companion and author of several books about gardening, including The Whole Herb (Square One, 2004).