Ask the master gardeners

Q: My child wants to grow plants from pits. What is a good pit to use for such a project?

A: An easy and rewarding project is to grow an avocado plant from its pit.
The avocado, Persea gratissima or Persea americana, is a fruit originally from South America that later migrated to Mexico. It is also known as alligator pear due to its pebbly skin.

Mostly used to make guacamole and to add to salads, avocado flesh is an excellent source of monounsaturated fat (the healthy one), as well as many vitamins and dietary fiber.

For this project, first scoop out the pit from a ripe avocado and rinse it to remove any excess flesh. Have your child insert 3 to 4 toothpicks at about the halfway mark of the pit. They should be placed far enough in so they support the pit without breaking.

Then take the pit and place it, pointy side up, into a glass of water, so that it is partially submerged. Place it in a sunny window and change the water every few days to keep bacteria from growing. It will take three to four weeks for the avocado seedling to sprout. After that, the pit will split open, with roots emerging from the bottom and a stem from the top.

Keep changing the water every few days, being careful not to damage the newly emerging growth. It will be time to transplant once the pit has developed a good root system (4 to 6 inches) and a stem with 4 to 6 leaves. Fill a pot with potting mix or good garden soil with a little peat or compost and gently place the pit into the soil, leaving about one-third of the pit above the soil surface.

Water lightly and place in a sunny location. Soon your child will have a beautiful avocado plant that he has grown from seed. The plant will need to be brought inside before the first frost. It will then become a delightful houseplant.
—  Margot Lee, South Nyack master gardener, Cornell Cooperative Extension of Rockland