When and How to Harvest Herbs
The best time to harvest herbs will depend on the herbs themselves. Most herbs should be harvested just as the flower buds appear, but before they fully blossom. At this stage, the leaves contain the maximum amount of oils for fragrance and flavor. You will also want to harvest them in the morning, just after the dew is dried, but before the sun is at its hottest.
Most leafy annual herbs can be cut back very heavily when harvested. You should use a sharp knife or pruning shears and cut just above a leaf or pair of leaves. Be sure to leave about 4 to 6 inches of the stem for later growth.
If you are growing an herb that is harvested for seed, do not cut it back. Wait for the plant to fully go to seed (when they are turning brown), and cut off the seed heads. Place these in a paper bag and wait until the seeds have dropped off, then place them on a paper towel or other surface until fully dried.
Perennial herbs should not be cut back as heavily as annual ones. You should only remove about a third of the top growth (or you can just cut the tips periodically throughout the growing season as needed). Most perennials are ready to harvest near or in the beginning of July. If you prune well the first time, you should be able to get a second harvest in September.
If you are harvesting flowers for craft purposes, cut them just before the flowers have fully opened.
Tarragon or lavender flowers should be harvested in early summer. To encourage a second flowering period in the fall, shear the plants to half their height.
Harvesting by Type
- Anise: You can snip leaves from the plant when they are large enough. To harvest seeds, wait till they turn brown, wash them in cold water and let them dry for several days.
- Lemon Balm: Fresh leaves can be picked anytime. For dry leaves, wait till the plant is just about to flower and harvest the top 3rd of the plant.
- Sweet Basil: For fresh use, harvest about 6 weeks after planting, when the leaves mature. For drying, harvest just before the plant blooms.
- Caraway: These seeds are harvested just after they turn a brownish gray color. Scald them in boiling water, strain and then let dry for several days on a paper towel or plate.
- Chervil: To use fresh, pick the tips of the stems once a month. For drying, harvest the leaves just before the blossoms open.
- Chives: Leaves can be harvested anytime during the growing season. Cut them off close to the ground and use fresh or dry them.
- Coriander: The leaves of coriander are only used fresh, and can be snipped as needed (as soon as the plants are 4 to 6 inches tall). To harvest seeds, wait until the heads turn downward.
- Dill: The leaves can be harvested as needed for fresh use. To harvest the seeds, wait until the heads have turned brown and remove the full head (place in a paper bag and wait for seeds to drop off).
- Fennel: Leaves can be used fresh as needed. Wait until the heads turn down to harvest seeds (place them in a paper bag until seeds dry/drop off).
- Lavender: Harvest the full flower stems just before the flowers are finished opening.
- Lovage: You can harvest young, tender leaves and use them fresh, or dry or freeze the leaves for later use.
- Sweet Marjoram: Cut back to about 1 in. above ground level just before flowering occurs (you will have a second harvest). Dry or freeze.
- Mint: Cut off at ground level just before flowering occurs. Use fresh or dry. (You should get a second harvest)
- Oregano: Harvest and dry just before flowering occurs.
- Parsley: Snip young leaves just above ground level as needed.
- Rosemary: Harvest young stems and tips as needed (but do not remove more than the top 1/3 of plant). For drying, harvest just before the plant blooms.
- Sage: Harvest when flowering begins and use fresh or dry.
- Summer Savoy: Harvest young stem tips as needed for fresh use, but harvest entire bundle when plants begin to flower.
- French Tarragon: Harvest in June for steeping in vinegar. For drying, harvest in early to mid July.
- Thyme: Cut the leafy stem ends with the flowers when in full bloom. Use fresh or dry.