The harvesting time of herbs is usually determined by the growing condition of the plant, rather than by a specific date or month. The majority of herbs should be harvested just as the flower buds first appear, but before they are fully open. At this stage of growth, the leaves contain the maximum amount of volatile oil, giving the greatest fragrance and flavour.

It is also important to harvest herbs at the right time of day. As the level of essential oils fluctuates with light and temperature, it is vital to harvest herbs at the right time to ensure that they are at their peak. Herbs should be gathered early in the morning, just after the dew has evaporated, but before the sun becomes too hot and evaporates the essential oils.

Harvesting Leaves and Shoots

Although harvesting the leaves just as the flower buds appear will capture the best flavours, they may also be picked at any time during the growing season. Evergreen herbs may also be harvested to a limited extent during the winter.

Annual herbs such as basil, coriander and dill can be cut back quite severely when harvesting. Use a sharp knife or pruning shears and cut just above a leaf or pair of leaves, leaving approximately 10-15 cm (4-6 in) of the stem for later growth.

However, leafy perennial herbs (chives, oregano, mint, rosemary and thyme) should not be cut back as heavily. Only about one-third of the top growth should be removed and in some cases, only the leafy tips. Always pick leaves in a way that will encourage healthy growth of the plant and maintain compact habit; select straggly or invasive shoots or pick the outer leaves of clump-forming herbs to encourage new growth in the centre.