Bitter Tasting Basil: What To Do When A Basil Plant Is Bitter

Basil Plant
bitter basil
(Image credit: Tendo23)

Herb growing requires a minimum of care, as the plants are normally fast growing and many of them already have some insect resistance due to the high amounts of essential oil in the leaves. Still, even these rather trouble-free plants can end up with issues. One such problem is bitter basil leaves.

Bitter Tasting Basil Leaves

A member of the Lamiaceae (mint) family, basil (Ocimum basilicum) is renowned for its aromatic and sweet tasting leaves. The herb is cultivated for the use of these leaves, which are high in essential oils and impart delicate flavor and aroma to a multitude of cuisines. It can be used either fresh or dried, although most people agree that dried basil doesn't hold a candle to fresh basil. The most common basil grown is sweet or Italian basil and is responsible for one of the great sauces of the world-- pesto. However, there are many varieties of basil to choose from, imparting unique flavor such as cinnamon, anise, and lemon to the evening's menu. Since basil is usually a fairly mild, sweet tasting herb, what would cause bitter tasting basil?

Reasons for Basil Going Bitter

Basil is a tender annual best grown in a sunny area with six to eight hours of direct sun exposure per day. Plant basil in well-drained soil amended with organic compost. Basil seeds can be sown directly into the garden after all danger of frost has passed or started indoors in trays to be transplanted when the seedlings have at least two leaf sets. Seeds should be barely set beneath the soil, about ¼ inch (6 mm.) deep and lightly covered. Water the seeds in. Germination takes place within five to seven days. Thin or transplant basil seedlings so they have a space of between 6 to 12 inches (15-31 cm.) between individual plants. Container grown basil needs to be watered more frequently, but garden or container grown basil should be kept moist. Feed your basil herb with an organic fertilizer. If you have followed the above instructions and still have bitter basil plants, the following causes could be to blame:


The primary culprit is lack of pruning. Basil needs regular pruning or cutting back to facilitate a robust, bushy plant with plenty of aromatic leaves. Another reason for pruning is to prevent the herb from blooming. Although blooming basil has ornamental value, in culinary terms it can be a disaster. Be vigilant and, at the first sign that the plant is trying to bloom, pinch the flowers off. Basil that is allowed to flower and form seed stops producing foliage and results in bitter tasting basil leaves. Pruning can be fairly aggressive, down to just above the lowest two sets of leaves. Snip at the node, just above a pair of leaves. Aggressive pruning will prevent the plant from trying to flower as well as engendering more flourishing foliage. You can prune this severely every three to four weeks.


If your basil plant is bitter, another reason may just be the variety. With over 60 varieties of basil available, it is possible, especially if you are not sure of the cultivar, that you may have planted one with unexpected flavor profiles. For instance, a cinnamon basil or spicy globe basil may yield a totally unexpected flavor, especially when your taste buds were expecting sweet basil.

Amy Grant

Amy Grant has been gardening for 30 years and writing for 15. A professional chef and caterer, Amy's area of expertise is culinary gardening.