The avocado is a tree that grows in tropical and subtropical areas of the world. Although you can plant an avocado in Missouri, once fall and winter arrives, the temperature extremes of Missouri's winter will quickly kill the plant. To get an avocado to thrive in Missouri, you must bring it indoors in winter. Growing an avocado in a pot from seed is simple.
Scrub an avocado pit with a nylon bristled brush until it is free of pulp and allow it to dry until the membrane coating cracks.
Score the top and bottom of the seed with a knife.
Fill a 6-inch container with one part peat moss, one part sand and one part compost. Water the soil until it is as wet as a wrung-out sponge.
Plant the seed 2/3 of the way into the soil with the pointed side up.
Place a plastic freezer bag over the container and place it in a sunny windowsill just out of direct sunlight. Check the plant daily to ensure that the soil is moist and water as needed.
Remove the bag once the seed sprouts.
Check your soil weekly. Water only if the soil becomes as damp as a wrung-out sponge. If your avocado sits in water, it may develop root rot.
Move your tree outdoors in summer so that it will receive full sun. In winter, move the plant indoors and place it beneath a grow light or in front of a south-facing window.
Fertilize a tree after it is 2 years old with a balanced (10-10-10) fertilizer according to package directions. Fertilizer instructions will vary between brands.
Transplant the tree whenever the roots outgrow the pot. An avocado tree's roots should be kept in a container that is barely bigger than the root ball.