Like most people, I was introduced to "grocery bag gardening" as a child. I was amazed that you could put an avocado pit into a glass of water or a pot of soil and, as if by magic, a beautiful plant would eventually appear. Or that a sweet potato would sprout glorious climbing vines if half-submerged in a glass of water supported by three or four toothpicks.
It wasn't until years later that I discovered that you can also grow such exotic subtropical plants as mangoes, papayas, litchis, macadamias, star fruit, coconuts and tamarinds from the pits of fruit you've bought at the supermarket. You can also grow citrus, kiwis, guavas, loquats, passion fruit, coffee beans, persimmons and pineapples--all in pots in your home or apartment.
Unfortunately, most of these plants won't produce edible fruit when grown indoors, but so what? Their beautiful, lush, unusual foliage is rewarding enough.
And growing "plants from pits" is a terrific way to get kids started on the plant and gardening experience, a wonderful way for children to expand their sense of responsibility and learn the rudiments of life and death in a relatively harmless manner.
Although the basic planting and care instructions are the same--easy--for most of these plants, here are some hints that will give you a much better chance of succeeding with them.
First, of course, you must obtain the fruit with the pits, most of which is available in our supermarkets.
Once you've enjoyed the fruit, remove the pits and plant them in small pots in a mixture of three-quarters commercial potting soil and one-quarter perlite or vermiculite.
There's no absolute formula as to how deep to plant the pits--remember, in nature the seeds just drop off the trees and sprout where they land--but a good rule of thumb is to plant your seeds about an inch below the top of the soil. Always plant several seeds, because some will germinate and others will not.
Unfortunately, there's no way to tell which seeds are viable (able to germinate) by just looking at them, but for best results, plant the seeds as soon as you can. The fresher the better--within two or three days is best.
Keep the pots in bright light and keep the soil warm and moist. In most cases your seeds will sprout within three to four weeks. If they don't germinate and start producing plantlets within a month, give up on them and plant some new ones.
Once the seedlings sprout and reach a height of 2 or 3 inches, weed out the weaker plantlets--they'll be obviously smaller and scrawnier than the rest--then repot the stronger, lusher, healthier seedlings into individual 2- or 3-inch pots in regular commercial potting mix. Once you've repotted your seedlings, start the general care as follows:
They all need lots of good, bright light. If they don't get it, they'll probably fail. A western or southern exposure is best for almost all of these plants.
Water often enough so that the soil doesn't dry out. You may have to water every day during the summer and only a couple of times a week during the winter, but make sure the soil is always moist.
As you would expect from plants whose natural habitats are tropical isles (or at least warm, humid places), plants from pits need lots of humidity. Spray them daily. And all of these plants prefer temperatures on the warm side. Don't let the temperature drop below 55 degrees--and remember that cold winter drafts can be deadly.
Now I'd like to introduce you to some of the plants from pits in my own "plantation" and give you special tips on how to grow them.
Avocado--( Persea americana ) . The avocado plant is a tall and quite handsome tree, with darkish-green, oval, pointed leaves. New growth is coppery red and appears throughout the year. Remove the pit from the center of the avocado and begin the germination process by planting your avocado pit directly into a 6-inch pot of commercial potting mix, pointy side up, leaving the top one-fourth of the pit above the soil.
Or--and this is the way we did it when we were kids--you can stand your pit, supported by toothpicks, in a tall glass of water (again, pointy side up), submerging the bottom three-quarters of the pit and leaving the top one-quarter above water.
In either case, with luck, the pit will split, producing a stem and leaves which will begin to grow upward. If you've germinated the seed in water, wait until the stem is about 4 inches long and then place it in a pot in potting mix, as above.
Keep the plant in a bright, sunny window and keep the soil moist. Spray the plant frequently, because avocado leaves tend to turn brown if they don't get enough humidity, and feed it every week with liquid house plant food. After the stem reaches a height of about one foot, begin pinching off the top growth to encourage bushiness. Your avocado will eventually reach heights of 5 or 6 feet.