Even in excellent growing conditions, getting an avocado tree to produce can be a tough job. Sometimes, even when the tree looks perfectly healthy, it may still seem reluctant to bear fruit.
There are nine common reasons why your avocado tree may be failing to bear fruit, ranging from simple (the age of the tree) to complex (excess salt in the soil). Many of these problems are solvable for growers who are willing to do some extra work.
How Avocado Trees Produce Fruit
Like all fruit trees, avocado trees develop flowers that become fruit when they are successfully pollinated. Unlike many other fruit trees, avocados are evergreen; they do not shed leaves in the fall nor do they have a true dormant period.
Because they are evergreen, some avocado varieties have very long growing seasons. “Hass,” for example, may produce fruit from January through July. “Fuerte” is productive from November through March (source).
These lengthy growing seasons can be fascinating for growers because, ideally, a single tree can set quite a lot of fruit during that time. But a lengthy growing season also means that there are more opportunities for the tree’s fruit production to be disrupted.
There are many problems that may cause a tree to drop the fruit it has produced. But if your tree is not setting fruit at all, the problem may be occurring further back in the fruiting cycle.
If your tree is not developing flowers, or if something is interfering with the flowers’ growth and pollination, your tree will struggle to produce fruit until that problem is solved. The problem may be simple, like maturity or overall tree health, or you may be dealing with a more complex issue like disease or pests. Either way, protecting your tree’s blooms is key to encouraging your tree to set fruit.
Before you look for problems, though, it is important to note that healthy, fully mature avocado trees can develop one million flowers each year–but of those flowers, maybe 200 will develop fruit. 200 avocados is a very successful harvest for one year, but it can be discouraging to see an abundance of flowers that fail to produce (source).
Furthermore, avocado trees have a six to eight-week flowering period, so it is possible that your tree will still set fruit, and all that is needed is some patience. If that’s not the case, read on to see other reasons why your tree isn’t yielding fruit.
Reason #1: Age of the Tree
When a tree is otherwise healthy, it seems natural to expect it to produce fruit once it reaches a certain height or diameter. Avocado trees, however, take a very long time to set fruit.
If you planted your tree directly from seed, you can expect to wait as little as five years or as long as thirteen years for your tree to bear fruit. Growers who planted their avocado trees as saplings have a shorter wait time–three or four years.
If your tree is not producing any fruit, but seems to be thriving, it may just not be mature enough yet.
What You Can Do
Be patient–especially if you planted from seed! While you wait, do everything you can to maintain your tree’s health by watering, fertilizing, and pruning regularly.
Furthermore, do not panic if your tree sheds a good deal of flowers when it does finally bloom. This is normal and not cause for alarm.
Reason #2: Planting A Seed From An Avocado You Ate
One popular activity for house plant enthusiasts is planting an avocado tree indoors using the pit of an avocado from a grocery store. This activity has been making the rounds on social media, and it seems like a great idea for people who have space for an indoor tree.
These growers are often frustrated when their avocado seedlings grow rapidly, become quite tall for indoor plants, and do not yield any fruit. The disappointing truth is that they probably never will.
Avocados simply do not do well in containers over the long run. In order to produce fruit, they need the assistance of pollinators, who are not welcome inside a home.
What You Can Do
If you have an indoor avocado tree, you might be able to transplant it outdoors if you live in a warm enough zone. They are best adapted to zones 8-11, due to their intolerance of frost.
You should know, however, that even if you do successfully transplant your tree, it still may not produce the fruit you expect. If the avocado which gave you the seed was a hybrid, then it carries characteristics of two different trees, one that supplied the “egg” and the other which supplied the pollen. The seed you planted will not have both characteristics, resulting in fruit that may be unfamiliar to you.
If you live in a climate that is not hospitable to avocados, enjoy your indoor tree as an ornamental for as long as possible, but do not expect fruit (source).
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Reason #3: Alternate Bearing Cultivars
If your tree has produced fruit in the past, but is not producing fruit this year, that may simply be how that particular cultivar works.
Some avocado varieties, including the popular “Hass” cultivar, are classified as an alternate bearing. Alternate bearing trees experience cycles of “on” and “off” years. During an “on” year, a healthy tree will produce a good crop; during an “off” year, the same tree may produce very little, if any, fruit (source).
What You Can Do
Again, be patient. If your tree is otherwise healthy, you can look forward to a better harvest next year. In the meantime, continue to water, fertilize, and prune your tree to encourage its long-term health.
Reason #4: Pollination Failure
Avocado trees are self-fruitful, which means they do not need another tree’s pollen in order to produce fruit; their flowers contain both male and female components. However, the pollination process for avocados is a little unusual because these components do not operate at the same time.
Each avocado cultivar falls into one of two types. Type A trees have flowers that function as female in the morning (able to receive pollen) and male in the afternoon (able to release pollen). Type B trees are on the opposite schedule, opening as male in the morning and female in the afternoon.
Some varieties, including “Lula” and “Taylor,” produce fruit quite well on their own. Others, like “Booth 8” and “Pollock” struggle to produce a sizable amount of fruit on their own (source).
Furthermore, if temperatures are below 60℉, or if pollinators like bees and wasps aren’t active when your tree sets flowers, your tree may not produce much fruit, if any.
What You Can Do
If your tree is a variety that doesn’t set fruit well on its own, plant a companion tree of the opposite type. Planting Type A trees near Type B trees can increase the chances of good fruiting, since the trees can cross-pollinate.
You can also attract more pollinators to your yard by planting colorful flowers like marigolds in strategic spots and avoiding broad-spectrum pesticides that may kill the insects your tree needs.
Reason #5: Temperature Extremes
Avocados are not frost-tolerant trees. Guatemalan varieties and Guatemalan-Mexican hybrids will show damage after a mere four hours at 30℉. “Bacon” and “Zutano” are the fairly frost-tolerant varieties, but even they can’t withstand temperatures below 24℉ for more than four hours. “Mexicola” is the hardiest, but only down to the low 20s.
When frosts occur, the damage will appear on your tree’s leaves and flowers first. Eventually, twigs and branches will appear drenched in water before darkening, withering, and dying back (source).
Unfortunately, if a late spring freeze kills your avocado tree’s flowers, your tree’s fruit production will be delayed.
Late spring freezes do not happen often in avocado growing zones, but fruit production is minimal–or nonexistent–when temperatures are consistently below 60℉ to 70℉.
Extreme cold is not the only potential problem for avocado trees. Extreme heat can also stifle your tree’s fruit production.
If temperatures exceed 90℉ for several days in the spring, your tree may drop its flowers and any little fruitlets it has already developed. This is the tree’s way of conserving water and energy for its leaves and branches.
The ideal temperature range for avocado trees is 70℉-88℉. Within this range, flowers can produce and receive healthy pollen and grow fruit without undue stress from their climate.
While there is no way you can control the temperature or your tree’s resistance, there are some things you can do to minimize the damage from frosts and heat waves.
Even with these protections, described below, your tree may still lose flowers during a freeze or heat wave, which means you may not see much fruit that season. However, protecting your tree during temperature extremes–thereby protecting its long-term health–can give you higher fruit yields in the future.
Unfortunately, if you live in a zone where winter temperatures dip far below freezing and summer temperatures rise far above 90℉–the Midwest, for example–your tree will maybe never set fruit, if it grows to full maturity at all.
What You Can Do
If your area is expecting a spring freeze, start by giving your tree extra water a few days in advance, then adding some mulch around the base of your tree. This will help maintain a steady soil temperature for the tree’s root system.
Just before the temperatures drop, create a canopy for your tree using a blanket, tarp, or plastic sheet. Anchor the cover’s corners to the ground–they do not need to reach the ground themselves–forming a kind of open tent.
Add a heat source. The source can be as small as a string of decorative lights or as large as an electric heater. Between the canopy and the heat source, you can spare your tree a good deal of damage.
Any time temperatures are predicted to soar above 90℉, but especially if those high temperatures will last several days, irrigation and mulch are your best defenses.
Mulch serves many purposes in a garden, but moderating soil temperature is one of the best reasons to add mulch around your avocado tree. Not only does it preserve heat during a surprise freeze, but it also keeps the soil from overheating during heat waves.
The day before temperatures skyrocket, water your tree using one and half times the usual quantity of water. During the heatwave itself, if it lasts multiple days, give your tree daily boosts of water to keep the shallowest roots hydrated.
Reason #6: Wind
In addition to their temperature sensitivities, avocado trees are also susceptible to damage from wind. When your tree is flowering, strong winds may damage the blooms or cause them to drop from the tree altogether.
Your tree’s flowers are not the only ones at risk from high winds. Winds can also cause defoliation (loss of leaves), which puts the trunk and branches at risk of sunburn. Furthermore, trees that have already set fruit may drop the fruit if the wind is strong enough.
What You Can Do
Sadly, no one can control the force of the wind. In some cases, you may have to cut your losses, keep your tree healthy, and wait for it to recover. You may, however, be able to limit wind damage.
When you prepare to plant, choose a location that offers some wind protection. Often, avocado trees do well on the south or southeast sides of structures where they have some shelter from north winds (source).
If your tree is still young, staking it can prevent severe damage such as a total collapse.
As your tree matures, prune it to remain a manageable size. Keeping your tree within ten to fifteen feet high can limit the possibility of storm damage (source).
Reason #7: Nutrient Deficiency
Avocado trees need a variety of nutrients from the soil in order to set fruit. Nitrogen, phosphorus, and potassium (listed as N-P-K on commercial fertilizers) are the most necessary, but avocado trees also need boron, copper, magnesium, manganese, and zinc in order to be in peak condition.
If your tree is not producing fruit, the reason could be nutrient deficiency. Even if you provide your tree with a typical balanced fertilizer, such as a 10-10-10 mix, your soil may still be missing some of the essential minerals your tree needs.
What You Can Do
First of all, avoid over-correcting by applying excess fertilizer. Instead, start by having your soil tested. A soil test can tell you which specific nutrients are lacking; you will likely not need to add huge amounts of each one.
If your tree is flowering, but failing to produce fruit, your tree may need a boost of boron. Boron is a mineral that plays a role in the tree’s pollination processes. Studies in Australia, California, and South Africa have shown that increasing an avocado tree’s levels of boron increased the pollen’s viability, which in turn increased the number of flowers that produced fruit (source).
Boron is available as a spray that you can apply directly to leaves and blooms, but many fertilizer mixes contain it as well.
Other critical micronutrients affect fruit production as well, particularly potassium and zinc. Potassium is already one of the foundational nutrients included in generic fertilizers, and zinc is available as a spray or as a soil additive.
When you look for fertilizers, look for ones that use 9-15% potash as their source of potassium. Potash is also a good source of magnesium, so you can provide your tree with both without any extra money or effort.
If your soil pH level is high, you may also need to give your tree iron to encourage fruit setting. Look for iron chelates that are specially designed for alkaline soils. This will probably not be necessary if your soil’s pH is balanced or acidic.
Again, be careful not to over-apply fertilizers! This is especially true of nitrogen. Your avocado tree needs regular applications of nitrogen, but excess nitrogen in your tree’s leaves can lead to hardier pest populations.
Reason #8: Excess Salts
Avocado trees are one of the most salt-sensitive fruit trees grown in the United States. This can be highly frustrating for growers, since many of them live in coastal regions where the groundwater naturally contains some salt.
You can tell if salt is a problem for your tree by looking at its leaves. Tip burn on leaves is a general indicator of excess salts in the soil. If left unchecked, entire leaves will die back.
In addition, the more salts are in the soil, the lower your chances are of harvesting an avocado crop.
Both of these symptoms are worse if your soil is clay. Clay soils do not drain well, which means any salt from the water will be retained, too.
It is also easy to confuse salt damage with a need for nutrients. Over-applying fertilizer, however, may add more chlorides to the soil, which increases its salinity.
What You Can Do
One of the best ways to minimize salt damage is root leaching. This is a process of occasionally giving your avocado tree extra water with the aim of pushing salts deep into the soil and away from the tree’s root system.
One clear problem with this is that using salty water to leach salts is counter-productive. This is where rainwater comes in.
If you live in a rainy area, rainwater is already doing the work of leaching salts away from your tree’s roots. Many growers also anticipate the dry season by investing in rain barrels or other rainwater collection systems so that they have access to non-saline water when they need to do some root leaching during dry periods.
It is also helpful to remember that your tree’s root system is shallow and extends in a circular pattern. When you water, do not neglect the outer reaches of the root system! Water slowly and deeply, covering the entire area beneath your tree’s canopy (source).
Finally, sticking to a regular fertilization schedule and resisting the urge to over-fertilize will limit the amount of chloride you may be unwittingly adding to your soil.
Reason #9: Irrigation Problems
Avocados are very exacting when it comes to water. They are susceptible to disease, poor vigor, and reduced fruit yields due to both under and over-watering.
Young trees need approximately two gallons of water every three or four days. Mature trees need about two inches of water per week, which is dozens of gallons depending on the size of your tree.
What You Can Do
Carefully monitor, as best as you can, the amount of water your avocado tree receives and irrigate it during dry periods.
To avoid overwatering, make sure the soil is dry before giving your tree more water. To avoid underwatering, water slowly enough to give the soil a chance to absorb it deeply, leaving no standing water on the surface. (Click here for signs of an underwatered avocado tree).
If your tree is failing to produce fruit, the best action you can take is to promote its overall health. Regular irrigation and fertilization are extremely important in keeping your tree healthy from one season to the next.
Be prepared for occasional climate problems like spring freezes and heat waves. Both of these can reduce or eliminate fruiting, but if you are prepared, you can minimize the harm.
If your tree is healthy and thriving, have patience! A good crop may still be a year or two away.