From the Wikipedia page 
Kukicha (茎茶), or twig tea, also known as bōcha (棒茶), is a Japanese blend made of stems, stalks, and twigs. It is available as a green tea or in more oxidized processing. Kukicha has a unique flavor and aroma among teas, due to its being composed of parts of the tea plant that are excluded from most other teas.
Kukicha has a mildly nutty, and slightly creamy sweet flavor. It is made of four sorts of stems, stalks and twigs of Camellia sinensis. For best results, kukicha is steeped in water between 70°C to 80°C (155°F - 180°F). Green varieties are best steeped for less than one minute (oversteeping or steeping too hot, as with all green teas, will result in a bitter, unsavoury brew).
It is common to steep kukicha for three or four infusions. Recommended steep durations: First infusion: 40 sec, 2nd: 15 sec, 3rd: 30 sec. Kukicha can also be added to juice to make a children's drink.