Grow Russian tarragon indoors from seed and plant out in the summer. Spreading plant can be divided easily. Start seedlings indoors well before the last frost in your area. Sow four or five seeds per pot in moist potting compost covering them with compost to exclude light. Transplant seedlings outdoors when the weather warms. Once started, these plants will grow well with little or no attention. Fertilizer always helps, but is only necessary in the poorest of soils. Mulching with organic matter in mid autumn will help them over winter if your area has particularly harsh winter weather.
French tarragon is grown from division of the roots. You can also propagate it by rooting small, vigorous cuttings in the spring. True French Tarragon cannot be grown from seeds.
Harvest and dry the leaves and flowers. Store them in a cool, dry place. Tarragon leaves can also be kept in the freezer. The best time to harvest is from mid to late summer.
Tarragon can be grown in containers for two or three years with no special care. It can also be over-wintered indoors if you have a sunny windowsill. One plant should be enough for a normal household’s requirements.