A 10 month old Avocado tree
I'm a sucker for free plants and anything I can grow from something I would normally throw away is especially exciting. I have been growing avocado trees from grocery store avocado pits for several years. I have figured out what works best for me and thought I would share with you.
I feel that I need to start with the disclaimer that the chances of an avocado tree grown from seed producing fruit is very small. I will explain more on this later.
How I start my tree
My preferred method for starting an avocado pit is to let it sit on the counter and dry out until the skin dries and cracks. I then peel the skin off the pit, wrap the pit in a wet paper towel and place in a ziplock bag. After 2-6 weeks, the pit forms a root and at this time I move the pit to a jar of water. I suspend the pit over the water with toothpicks having the bottom 1/2 inch of the pit and the root in the water. The reason I prefer the ziplock bag method is that I have found my pits form roots faster in the bag than when I start them with toothpicks over water. I'm guessing it might have to do with the humidity in the bag.
Once the stem starts growing and reaches 6 inches, I cut it down to 3 inches to encourage branching. At this time I pot up the pit in organic potting soil with the top 1/3 of the pit above the soil line. When the stem reaches 12 inches, I cut it down to 6 inches to again encourage branching and stem growth.
9 month old tree that developed a double stem
There are two different types of avocado trees which is important for pollination. Avodado flowers have both male and female parts which would be great for pollination if they were open at the same time of the day. Unfortunately, one type of avocado tree has flowers with females open in the morning and males open in the afternoon, while another type of avocado tree has flowers with males open in the morning and females in the afternoon.
You can see why this is a problem. If you have two trees with female flowers that open at the same time there is no chance of pollination.
The ideal situation is to have trees of both types to ensure pollination occurs.
Avocado trees grown from seed take anywhere from 5-13 years to flower and fruit. Because I have just one older tree (3-4 years and has never flowered), it will be quite a while before I have a second tree old enough to flower and help pollinate and even then, it's a 50/50 whether or not the second tree will be a different variety.
If I get avocados it would be very cool, but I like growing these trees from seed even if I never get any fruit. They are free, easy and low maintenance. I do bring my avocado tree into my unheated garage over winter here in zone 7b/8a to keep it safe.