Technically a tropical grass, sugarcane is grown as an edible crop in tropical climates that have mild winters. Sugarcane can grow up to 13 feet tall, but it can be harvested when it's only 3 feet in height. You can easily grow sugarcane in your greenhouse from sugarcane stalks sold at most health food or ethnic grocery stores for chewing. As long as you have heating elements set up in your greenhouse, your sugarcane-growing experience will be simple and rewarding.
Saw the tops of the sugarcanes to make them into 5 1/2- to 6-inch seed pieces, also called "setts." Use only the freshest sugarcanes for planting.
Fill a seed tray that has drainage holes in the bottom with a mixture of equal parts grit, such as coarse sand, and organic compost.
Lay the setts flat on top of the mixture, and cover them with a light sprinkling of compost.
Sprinkle or mist the compost and setts with warm water from a spray bottle.
Place your seed tray inside a covered frame or a clear plastic bag, or place a clear seed tray cover on top of the tray.
Place the seed tray on top of a heating element and in bright light in your greenhouse, set to warm the compost in the seed tray to at least 68 to 70 degrees F. Maintain air temperatures in your greenhouse at 65 to 75 degrees.
Water the compost and setts very lightly, if at all, until the canes sprout, which usually takes about three weeks.
Remove the plastic bag or covered frame from the seed tray after the shoots emerge and grow to about 3 inches tall.
Fill 6-inch-diameter planter pots that have drainage holes in the bottom with a mixture of equal parts potting soil, organic compost and coarse sand or grit.
Carefully remove the sugarcane seedlings from the seed tray, and plant them individually in the pots.
Place the pots in bright light and water your sugarcane plants two or three times each week to thoroughly moisten the potting mixture and until water drains freely from the bottom of the pots.