If you are like most of us, you love avocados, and would like to be successful in growing your own trees and fruit. This posting are notes from a recent lecture by Ellen Baker and Freddy Menge of Epicenter Avocado nursery, in which they provided a lot of guidance.
First thing to mention is, you are not likely to succeed with a seedling tree! That pit you have been growing out could be grafted over perhaps, but if you have limited yard space, you may want to start with a purchased tree.
Plant the tree and get it growing!
For new trees, the best time to plant is as early in the spring as possible, after the danger of frost, in order to give a long season of growing before the weather gets cold again. Check the Epicenter Avocado website for great step by step photos of how to plant!
If your avocado tree is new, or established, it will want the same thing… Plenty of mulch, and moist but not wet soil, and plenty of weak forms of nitrogen, like composted manure or alfalfa meal, or commercial plant food in the neighborhood of 4-4-2. If you don’t see a large red flush of new growth in spring, then your tree probably needs more fertilizer. In fact, it is a good idea to keep applying that fertilizer every month or two right through until November.
More red shoots and leaves means more flowers, and more flowers means more chance of a crop. Under optimal growing conditions, only a very small percentage of flowers can be successfully pollinated!
And, fertilizer into the fall means you get more leaf growth rich in nitrogen, and these leaves are better able to tolerate the frost!
Sometimes we’re too hot, and sometimes too cold…
Avocados come from a semi tropical region, and they really do not like to get too cold. Even though most of the Bay Area is pretty mild, we do get some low temperatures. If the tree can be protected from the soil line to about one foot above the graft, it should be able to bounce back from even a killing frost. Some ways of protecting that important region, can be using a string of lights around the graft, or by building a mound of lightweight insulating material like wood shavings and leaves around the trunk.
As far as too hot… The trees like plenty of water in the summertime. Remember they come from a humid area of the world. They also can easily get sunburned. In their native environment, they start out as understory trees with moderate shade. If the bark gets burned, that really sets the tree back. So many recommend a “whitewash” of the southern facing trunk and large branches. Whitewash can be made from a. Mixture of 50% interior latex paint and 50% water, painted right onto the wood. Good leaf coverage helps protect against sunburn.
Flowers; or the sex lives of avocados!
It is common to get the advice that avocados need to be paired, with an “A” type and a “B” type together. Avocado trees are unusual in the plant world, in that any given flower does have both male and female parts, but they are present at different times of day! The reason for having both “A” and “B” type trees is that the “A” is female when the “B” is male, and visa/versa. This rule holds true in Mexico and Guatemala where the trees originate, and probably holds true in Southern California.
But, Central California temperatures are often too cold for the “B” type flowers to go from male to female. That process happens at night! If the flower does not convert to female, it cannot be pollinated! So “B” type may not yield much fruit in this region, though the tree may be better at surviving cooler temperatures.
The good news is that “A” trees can pollinate each other! And many people prefer the“A” type fruit, as it is generally more oily and rich in flavor.
Trees which are “A” type can have a long flowering season with cool temperatures, having more opportunity to be pollinated. And they can have some flowers be female at the same time others are male. Or sometimes they even have both parts at once, and can pollinate themselves. A good rule with avocados in Central California is that fruiting is generally more successful the more “A” type avocados you have!!
More birds and bees…!
An additional problem is that honey bees do not like the pollen of avocado flowers!! So we have to rely on other pollinators! Don’t worry, there are many flying critters that do like avocado flowers, like syrphid flies, and bumble bees and crane flies. You will see more of these helpful pollinators if you also have a diversity of ornamental flowers attracting them to your yard. They need pollen or nectar for many months of the year, and they won’t hang around if you don’t have flowers for them.
But I don’t have room for a lot of trees!
Avocado trees can be quite large. But there is evidence that planting trees close together helps to keep them smaller. And they do tolerate fairly heavy pruning. Ellen and Freddy mention pruning the equivalent of 1/5th of the tree every year. They also report on an avocado “guru” in Orange County, who keeps her trees at 6 feet and under.
But which varieties are really good?
Really, planting as many as you can find room for seems a good idea. And while you are at it, make sure each one is a different variety! Why? Diversity contributes to success and to different ripening times,
Again, “A” type avocados are preferred in our area!
The website at Epicenter Avocado, does have a listing of many different special varieties, with more description of each. Some names you will see at other local nurseries are: Hass, Lamb Hass, Reed, and Pinkerton. All are really good avocados in our region.
When you are ready to pick those fruits, they should lose a bit of their shine, and take on a bit of a dusty bloom. Some need to (or can) hang on the tree about 18 months in order to develop their best flavor.
A warning though, tasting a tree ripe avocado will make it difficult to go back to store bought!