Three Ways to Grow Avocados from Seed
Back in the day, hippies from here to Northern California sprouted their avocado pits and kept the trees in their apartments. If every hippie and their best friend grew them, how hard could it be? Yeah, that’s what I thought.
A few years ago I tried sprouting some, I put a couple pits in dirt and a few more suspended by toothpicks in jars of water. Nothing happened. I blamed it on some sort of treatment the avocados had been through. Now I know better. I think I made two mistakes, no, three. The first mistake was thinking that the radical sprouted from the side of the fruit, like squash seeds, so I planted them on their sides. Wrong. For the best results, the pointed-end should be placed at the top. Some are more subtly shaped than others. The bottom is usually flatter and there is most often a circular marking in a slightly lighter color.
The second mistake was allowing the soil to dry out.
The seeds of avocados, like many tropical trees and fruits are recalcitrant, which means they cannot dry out, or they won’t germinate. Seeds like this cannot be kept outside of the fruit. Sellers who offer recalcitrant seeds often sell them in moist peat, or even pre-germinated.
The third mistake was not waiting long enough. I would say the average germination time has been six weeks.
Planting is soil and suspending in a jars have worked equally well for me. There are advantages and disadvantages to the jar method. An advantage would be the cracking open and emergence of the root is very visible, but the disadvantage is that the jar requires numerous cleanings and water changes during the six weeks. Another disadvantage is the transfer from jar to pot. When I removing a pit from the jar it slipped out of my hand, flew across the room, and landed on the floor, snapping off part of the radical. It was okay and grew normally nevertheless.
The third way to sprout avocado seeds is in the worm bin, the bin provides an excellent balance of conditions favorable for germination. I tossed a couple in my worm bin approximately two weeks later they are beginning to crack. Remember which area of the bin they are in and be careful finding the pits because the roots are very delicate.
Avocados take an average of ten years to reach fruiting size and they will only do so in tropical climates. Avocados fruit best when cross-pollinated with a different cultivar. Because of the dichogamous flowers self-pollination is rare. Darwin was the first to hypothesize that dichogamy was a mechanism to prevent inbreeding. Even though they won’t fruit, for most of us, they are still lovely ornamentals.