Grow houseplants from leftover greens, pits, and seeds

With school now in full swing, growing houseplants from kitchen scraps makes a fun science project to enjoy with your children or grandchildren. Here's a good book to get you started: No-waste kitchen gardening : regrow your leftover greens, pits, seeds, and more by Katie Elzer-Peters. 

Potato. Cut a potato into sections, leaving at least one eye on each piece. Plant the pieces three inches deep in a container of moist potting soil. The result: a fast-growing bushy plant with pretty green foliage.

Sweet potato. Cut two inches off the bottom of the potato and insert toothpicks at one-inch intervals an inch up from the cut bottom. Immerse the cut end into a jar filled with water. Place in a bright location out of direct sunlight. The jar will soon fill with roots. The result: a long, rambling vine with heart-shaped, lime green leaves.

Citrus/apple. Soak seeds overnight to soften and then plant as deep as the size of each seed in a loose seed-starting mix. Place in a warm location and keep the soil moist. The seeds can take up to a month to sprout, so be patient. Once the seedlings emerge, place them in a sunny window. The result: little indoor trees.

Carrot. Use fresh carrots with green tops. Cut all but two inches of foliage off the top and slice the bottom so that it is a one-inch stub. Work the stub into a moist mix of 50 percent potting soil and 50 percent horticultural sand. The result: lacy foliage will grow from the top of the carrot, eventually producing tiny white flowers.

Garlic/ginger. Bury a clove of garlic or a piece of ginger root in moist potting soil, covering with one-half inch of soil. Keep moist but not soggy. The results: the garlic will produce green, scallion-like foliage that can be used in salads and stir-fries. The ginger will grow palm-like leaves and eventually more edible ginger root below the soil.

Pineapple. Take the prickly top of the pineapple and remove a few of the bottom leaves until you have a small stump. Let the stump air-dry for two days, then put the pineapple top over a jar of water, immersing the stump. Place in a warm location and expect roots in one to two months. After rooting, plant the pineapple in potting soil. The result: a plant with striking sword-shaped leaves that may eventually produce flowers that bear small pineapple fruit.

Avocado. Stick three to four toothpicks into the centre of the avocado pit and place pointy side down into a jar filled with water. Immerse one-third of the seed in the water. Roots will grow from the bottom of the seed and a stem will rise out of the top. The result: a tree with dark-green, shiny leaves.