Now in July is the ideal time for harvesting herbs, because most herbs now have their best healing powers and aromas. This is true for the aromatic herbs from the garden (e.g. sage, rosemary) as well as for the wild growing medicinal plants from nature (e.g. thistle, yarrow). If you want to preserve the aromas for the time until the next harvest, there are various possibilities. Here is what is important when drying herbs.
Fresh in summer, dried in winter
Basically, for teas and spices, you can use both fresh and dried parts of the plant for this purpose. A preparation from fresh plants is always more substantial. Therefore, in the summer, take fresh herbs for their tea and spice cooking, if possible. Then in the fall and winter, the dried supplies come into their own, because during this time the plants withdraw their active ingredients and wither.
The right harvest weather if you want to dry the herbs
If you want to dry aromatic herbs, it’s also worth taking a look at the weather. Fortunately, you don’t need an umbrella when picking herbs, because herbs are sun worshippers. So good weather is the guarantee of a good harvest quality! After all, in rainy weather they produce much less aromatic substances.
But too hot days are not optimal either. Because when the sun really burns, the essential oils partially evaporate from the plant cells. However, these fragrances are important healing and seasoning substances. Therefore, use dry days when it is not too hot.
The best time of day for harvesting herbs.
Each plant contains several hundred active substances. These substances are also called secondary plant substances or phytochemicals. The metabolic processes in the plant’s “chemistry laboratory” ensure that the active ingredient content in the plants changes constantly throughout the day. So there is also an optimal time of day for harvesting. Fortunately, most plants are late risers. If you go on a collecting spree between 10 a.m. and 4 p.m. (daylight saving time), you can’t go wrong. Towards evening, the active ingredient levels decrease again. There are only a few exceptions to this rule: Flowers that open early in the morning (for example, mullein, chicory and corn poppy flowers) are picked as early as 9 a.m., because by midday they become limp or even fall off.
Why it is worthwhile to dry herbs yourself
Basically, dried herbs have some disadvantages compared to freshly gathered herbs. For one thing, the drying process inevitably results in loss of flavor and active ingredients due to the heat supplied and enzymatic processes. Secondly, dried medicinal plants are usually stored for several months to years after processing, which also results in quality losses.
Now it is unfortunately the case that industrial processing in particular results in very high quality losses. This is because commercially available herbs (tea, spices, medicinal plants) are usually very heavily crushed. However, herbs cut into millimeter size behave like an open bottle of mineral water, which gradually loses its carbonic acid. Uncrushed leaves and flowers, on the other hand, resemble a closed bottle: they preserve the aroma and active ingredients until they are needed. For example, there are studies that show that crushed peppermint loses 35% of its essential oil during one year of storage, while only 5% of the essential oil is volatilized in uncrushed peppermint leaves. So crushing is a big mistake! Another advantage of hand selection is the clean quality, because any damaged, dirty or diseased leaf can be sorted out. With mechanical harvesting and processing, nothing is sorted. Everything is mown, chopped and dried. Therefore, it is definitely worth it to harvest and dry yourself, and then do everything right.
Drying herbs – but correctly
Drying herbs is an indispensable method of preservation because fresh peppermint leaves, for example, are not available year-round. Now, if you want to dry leaves or flowers for stockpiling, make absolutely sure that you do not chop them. This is because valuable active ingredients are lost at every cut or broken point during drying and during subsequent storage. Whole leaves and flowers, on the other hand, behave like small preserves. Only when you prepare a tea or season a dish do you crush the dried plant parts, because now the aromatic substances from the plant cells should get into the medium. You will be surprised at the high content of active substances and aromas in the herbs you have dried yourself.
The optimal drying: warm, airy and dark
For drying, carefully strip the leaves from the stem and spread the picked flowers thinly in a warm shady place. It is best to lay out the leaves and flowers on clean surfaces or on a drying frame. You can make such drying frames yourself. Thin cotton fabric or fly gauze is suitable as a covering material. You can also line a large basket or box with a cloth and spread the plants on it. Or you can lay a thin cotton or silk cloth over a clothes horse and spread your collected herbs on it.
To allow air to get everywhere and moisture to evaporate well, the herbs are laid out loosely, preferably leaf to leaf or flower to flower, so that the plant parts are not close together. It is also helpful to turn the herbs frequently during the drying period.
For plants with only small leaves, such as thyme or quender, you can also dry whole twig pieces (about 10 cm long). With such twigs, it is also possible to tie small airy bouquets of herbs to hang in a warm but shady place.
In any case, it is not dried in direct sunlight, because this will lose important active substances and the dried material will fade.
Artificial drying with hot air
Special dehydrators are also available for drying, which bring about very rapid drying by applying heat. The temperature must not exceed a maximum of 40 °C in order to avoid loss of active ingredients. Such dehydrators are particularly useful for plants that are very difficult to dry in ambient air. These include, for example, the flower heads of marigolds, the leaves of basil and sage, or the flowers of mullein. Artificial drying also has the advantage that it can be done regardless of the weather. This is because it is quite possible in summer that natural drying is hardly possible in high humidity.
Bark and roots (e.g. angelica) are somewhat more difficult to dry due to their solid cell structure. They have long drying times and release water only with great difficulty. Here it is exceptionally useful to cut the plant parts into larger pieces or slices and then dry them with artificially supplied heat, i.e. either in dehydrators, on the heater or in the oven. The situation is similar with fruits (e.g. elderberries), which hardly dry properly in the natural ambient air.
Drying herbs is also about time
Fast drying is desirable so that no value-reducing enzyme reactions can take place in the herbs during drying. Ideal drying time is 3-4 days. If your herbs are still not dry after 10 days, then it is urgent to artificially re-dry. You can also use the oven for this purpose. This is very fast, because the herbs are already pre-dried for several days. Do not let the temperature rise above 40 °C. To be on the safe side, you can add a thermometer to check. Leave the door of the oven ajar so that some heat, but especially the moisture, can escape from the oven.
Check quality before bottling
Herbs are only perfectly dried when the leaves can be crumbled effortlessly between the palms of your hands. Or perform the “stem test”, because the stem of a leaf or flower head takes the longest to dry: when it cracks and is no longer pliable, then you can end the drying phase.
If the drying has gone optimally, then the plants have retained their color. Gray, brown or even black leafy herbs are a sign of enzyme reactions and loss of quality. They have been dried too warm or too long and have thus lost some of their flavor and ingredients. Optimally dried leaves and flowers show up in beautiful, variegated or even bright colors.
Store dried herbs well: Dark, dry and cool.
After professional drying, you can fill the plant parts uncrushed into tightly closing containers. Screw-top jars with a tight seal are best suited for this purpose. In them, the plants are equally protected from food moths and humidity. Some medicinal plants, such as mullein flowers or marshmallow roots, tend to absorb humidity like a sponge. Here you should recheck from time to time and re-dry if necessary.
Optimal storage containers are jars made of brown or violet glass, because they hardly allow UV light to penetrate. If you use white glass, then store the dried plants in a dark cupboard. This is because light also reduces the quality during storage. For storage, the cooler and darker the storage location, the better the shelf life.
Properly stored, you can easily keep your self-collected, unchopped herbs for 3 years. However, small cut teas that you have purchased should be used up within a year, because they constantly lose active ingredients due to the comminution.
I have 30 years of experience and i started this website to see if i could try and share my knowledge to help you.
With a degree a Horticulture BSc (Hons)
I have worked as a horticulture specialist lead gardener, garden landscaper, and of course i am a hobby gardener at home in my own garden.
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