top of page

Harvesting and Preserving Herbs

Harvest time is such a fun time of the year. There are so many herbs to harvest and preserve for the upcoming winter months. Some share their bounty year after year, like tarragon and oregano, and others, like basil and marjoram, are planted in spring for a fall harvest.

Shari Mayer, Master Gardener

Harvesting and Preserving Herbs

I’m always playing with herbs in my yard, tucking them into the landscape, my gardens, and containers. Wherever they end up, as fall approaches, my attention turns toward harvesting.

I’ll share a couple of harvesting techniques that have worked well for me over the years. Personally, I tend to wait as long as possible before the final harvest. Oftentimes I find myself gathering armfuls of herbs to bring indoors in a race against inclement weather, especially my frost-sensitive herbs. Looking at mountains of plant material all over my kitchen counters and in buckets makes me sometimes wonder what I was thinking way back in the spring! Anyway, here are some techniques that help me prolong the fresh herbs for cooking and make short work of processing. These methods preserve the flavor and essential oils, which is what it’s all about.

First, prepping for harvest is important. I don’t like to waste an enormous amount of time washing and drying herbs once they are inside, so I try to use the gift of rain. This washes the majority of dust, dirt and debris from the herbs. It also ensures they are hydrated just prior to harvest. If no rain, then I achieve the same effect with a garden hose.

My favorite way to process a lot of herbs is what I refer to as the ‘slurry’ method. I’ll use basil, since it is a perfect example. Basil does not like temps below 50 degrees F, and discolors to an unappetizing brown if cold and wet. This method preserves the color and makes it super simple to use in cooking. The key to a slurry is the ratio of fresh, packed herbs to oil. Use a 4:1 ratio. The process is simple. Two cups packed leaf material and ½ cup oil (my favorite is olive). Do not use woody stems. Using a food processor, start pulsing the leaf material, and slowly add the oil until incorporated. The mixture should be thick and pourable, but not runny. Fill ice cube trays and freeze the mixture. Once frozen, store in freezer bags. I mark the bags with ice cubes that equal 2 cups of herbed cubes. This is the base amount to make one recipe of pesto. If you want to make a pesto, just thaw, and add the remainder of pesto ingredients to it. Otherwise, for cooking, just pop an ice cube or two as needed or desired. The slurry method works well also with water as an oil substitute.

Another favorite technique of mine is to make herb bouquets. I just go outside and collect herbs as you would cut flowers, and bring them in and arrange the herbs in vases. If the herb is annual, such as basil, I will cut it right at the ground level and bring the whole plant inside. If it is a perennial, such as tarragon, then just bring in a number of branches. They last for weeks this way, and provide fresh herbs for your cooking well into fall. I find the varied greens of the herbs are as beautiful as flowers.

There are so many ways to preserve herbs, but these are a couple of my favorites. Here’s to fall bouquets of green!

Photo credits Emily Murphy, “” (1), University of Minnesota Extension (2, 3, 4)

bottom of page