When fully mature and dry, the seeds of Black Sesame are very dark indeed. The colour difference between the varieties is obvious if they are placed side by side. This seed has a richer, nuttier flavour than its white and gold cousins, and the plants need strong heat to be productive. Sesame as a plant is not simply drought tolerant — it requires drought for good pod and seed production, and this makes it an excellent plant for xeriscaping. The plants are indeterminate, and will keep producing new flowers and seed capsules until the nights get cool in the fall. The black seeded variety is popular in Chinese, Korean, and Japanese dishes both sweet and savoury, and is particularly rich in oil. Its flowers are highly attractive to bees.
Matures in 75-110 days. (Open-pollinated seeds)
Sesame is commercially produced in desert settings, so when we say it’s drought tolerant, we really mean it. In fact, this is really the key to success with sesame seeds, as we will outline in the following guide on how to grow sesame from seed. Sesame is a tropical annual herb that grows to about 60cm (24″) tall. Its leaves radiate out from a stem that is square in cross section.
Season & Zone
Season: Hot season
Exposure: Full sun
Zone: Not hardy
Sow seeds indoors 4 to 6 weeks before the last average frost date. Transplant under cover a similar period after the last frost date. Remove the cover some time mid-May to early June, once the night time temperatures are warmer. The days to maturity is from transplant date, as these seeds do not respond well to direct sowing.
Lightly cover the seeds with sterilized, soil-less starter mix, and keep just moist until germination. Don’t keep the seeds in a highly damp environment, and be sure not to over-water the seedlings. Once they sprout, reduce watering to once a week until transplant time. Optimal soil temperature for germination: 21°C (70°F).
If steps are taken to increase warmth in and around the plants, they will be more productive. Try transplanting into a raised bed, or into the ground using black plastic mulch over the soil. Do not fertilize sesame plants, and avoid drip irrigation, as they really do like it dry. Plant fairly densely at 15cm (6″) spacing, in rows 60-45cm (24-36″) wide. Sesame is indeterminate, so it will continue to bloom and set seed capsules until the end of summer. Expect flowering to peak in July and August.
The tubular flowers of the sesame plant are highly attractive to honeybees, and are said to produce some of the highest grade of honey. The plants are relatively self-fruitful, so when the flowers open, the seeds are already fertilized. The seeds are produced in pods (seed capsules) that appear along the stem.
Around the end of August, some of the pods near the bottom of the stem (the first flowers that opened), may begin to show signs of ripeness. When ripe, the pods begin to split from the blossom end. Don’t worry if this doesn’t happen in the field. Before wet weather arrives, cut the stems at the base and gather them to dry some place that is flat — hanging them will cause the seeds to just fall out as the pods dry. As the plants dry, the foliage will darken and more pods will open from the base of the stem upwards. Once most of the pods have opened, bash them against the sides of a bucket to collect the dry seeds. The seeds are edible at this stage, and resist spoilage better than most nuts. They can also be toasted, pressed for oil, or ground into the paste known as tahini.
Sesame plants each produce quite a lot of seeds, but the seeds have little mass. From a 10 foot long, 2½ foot wide row, expect to harvest approximately 425g (just under one pound) of seeds.