What Season Do Avocados Grow and When Are They Harvested?

Avocado trees grow year-round in subtropical and tropical climates, but their fruit develops on a seasonal cycle that varies dramatically depending on where in the world the tree is planted. In California, the dominant U.S. growing region, Hass avocados flower between February and May and reach commercial maturity roughly six to eight months later, though harvest can stretch across most of the calendar year because avocados have an unusual ability to hang on the tree long after they’re ready to pick. The global supply chain layers harvests from Mexico, Peru, Chile, Colombia, and other producers so that fresh avocados appear in grocery stores in every month, but the biology behind that availability is more interesting than most shoppers realize.

The Flowering and Fruiting Cycle

Avocado trees follow a pattern of vegetative growth flushes punctuated by flowering. In southern Spain, where the cycle has been carefully documented, trees put out two main bursts of new shoots: one in spring and one in summer. Floral buds begin forming in autumn, then the trees bloom the following spring alongside the first flush of new leaves.¹ That general sequence holds in most subtropical growing regions, though the exact calendar months shift with latitude, altitude, and local climate. In Queensland, Australia, researchers have identified the specific genes that switch on at the time of floral induction, confirming that the tree responds to seasonal environmental cues to begin its reproductive cycle.²

Once flowers open successfully and pollination occurs, the tiny fruitlets begin a long development period. Most of the avocados you see in stores are the Hass variety, and Hass fruit typically needs six to eight months on the tree before it accumulates enough oil and dry matter to be considered commercially mature. But here’s the unusual part: the fruit can stay on the tree for many additional months beyond that minimum without spoiling, effectively using the tree as a living storage unit.

When Avocados Are Harvested in California

In southern California, Hass trees flower from about February through May, and the resulting fruit reaches maturity sometime between late fall and the following spring. Because growers can leave fruit on the tree well past the minimum maturity point, the California harvest window stretches much longer than you might expect. One long-running rootstock trial in California harvested trees in April, roughly 12 to 14 months after fruit set, meaning those avocados had been hanging on the tree for over a year.³ That flexibility allows growers to time their harvest to market prices and demand rather than a strict biological deadline.

A study that tracked Hass avocados across four California growing areas sampled fruit in January, April, July, and September. Fat content and total carotenoids rose steadily from January to September across all locations, meaning later-harvested fruit had richer nutritional profiles and creamier texture.⁴ The practical takeaway: California avocados picked in late summer tend to be fattier and more flavorful than those picked in winter, even though both can be perfectly acceptable. Peak California season typically runs from spring through early fall, with the heaviest volumes in late spring and summer.

How Climate and Altitude Shift the Calendar

If you zoom out from California to the world’s tropical growing regions, the timing of avocado seasons gets more complicated. Temperature is the main lever. In Colombia, researchers tracked Hass avocado phenology on farms at different elevations and found that altitude caused enormous differences in how fast trees moved through their growth stages. On farms below about 2,200 meters, the period from bud formation to the start of reproductive development was roughly 60 days total. On farms above that elevation, the same phases stretched to around 180 days. The fruit development phase alone varied by almost 100 days between the lowest farm at 1,753 meters and the highest at 2,453 meters.⁵

The reason is straightforward: warmer temperatures at lower altitudes push the tree through its stages faster, while cooler highland conditions slow everything down. This is why countries near the equator can produce avocados at different times of year depending on which region the orchard is in. A farm in a warm Colombian valley might harvest months before a highland farm planted at the same time. Mexico, the world’s largest avocado producer, benefits from a similar range of microclimates. The state of Michoacán, which produces the bulk of Mexico’s crop, harvests year-round partly because orchards sit at varying elevations with different growing calendars. Peru and Chile, in the Southern Hemisphere, add their own offset: their spring and summer run from October through March, so their harvest peaks fill the gap left by Northern Hemisphere off-seasons.

Why Avocados Don’t Ripen on the Tree

One of the strangest things about avocados, and the trait that makes their harvest timing so flexible, is that they refuse to ripen while still attached to the tree. Unlike a peach or a banana, an avocado will not soften on the branch no matter how long you wait. It only begins to ripen after it’s picked. This quirk is what lets growers treat the tree as a natural warehouse, leaving fruit hanging for months past maturity. But it also creates challenges: because the tree flowers over an extended period and only a tiny fraction of flowers actually set fruit, the avocados on any single tree can differ widely in age and maturity.⁶

That heterogeneity follows the fruit from the farm to the packing house and eventually to your kitchen. Two avocados sitting next to each other in the same box may have been on the tree for different amounts of time, which partly explains the maddening inconsistency consumers sometimes encounter. One avocado ripens perfectly, the next one from the same bag goes from rock-hard to brown mush without ever passing through the creamy sweet spot. The extended flowering window and low fruit-set rate are biological traits of the species, not signs of bad farming.

The Avocado’s Unusual Pollination Dance

The flowering behavior that precedes fruit set is genuinely one of the odder systems in agriculture. Avocado flowers are bisexual, meaning each flower has both male and female parts, but the parts don’t function at the same time. In Hass and other “Type A” varieties, each flower opens first in the morning in its female phase, receiving pollen. It then closes, reopens the next afternoon in its male phase, and sheds pollen. Temperature controls the timing of this cycle: at warmer temperatures the two-day overlap between female and male opening creates a short window for cross-pollination, while cooler conditions can throw the schedule off and reduce fruit set.⁷

“Type B” varieties flip the script, opening female in the afternoon and male the following morning. The idea is that planting Type A and Type B trees near each other allows cross-pollination, since one type is releasing pollen while the other is receptive. In practice, the system is imperfect. Temperature swings can desynchronize the timing, and even under ideal conditions only a small percentage of the millions of flowers an avocado tree produces will set fruit. A healthy, mature Hass tree may bloom with hundreds of thousands of flowers yet yield only a few hundred avocados. That extreme dropout rate is normal for the species and is one reason avocados have always been relatively expensive compared to other subtropical fruits.

Alternate Bearing and Unpredictable Harvests

Even when everything goes right with pollination and weather, avocado growers face another seasonal headache: alternate bearing. This is a pattern where the tree produces a heavy crop one year and then a much lighter crop the next. The phenomenon is well known across many fruit trees, but avocados are particularly prone to it. Large swings in yield between consecutive years remain one of the biggest obstacles to steady commercial production.⁸

The basic mechanism is that a heavy fruit load in one season uses up so many of the tree’s resources that it has less energy to invest in flowering the following spring, leading to a light year. The light year, in turn, allows the tree to bank energy and produce an abundant bloom the year after. Growers try to smooth this cycle through pruning, thinning fruit, and adjusting fertilization, but it’s difficult to eliminate entirely. For consumers, alternate bearing is one of the reasons avocado prices can spike from one year to the next even when there hasn’t been an obvious drought or weather disaster. The tree itself is cycling through a boom-and-bust rhythm that takes more than one growing season to play out.

How Fresh Avocados Survive the Journey to Your Store

Because avocados ripen only after harvest, the entire global supply chain depends on controlling that process so fruit arrives at the store firm enough to display but close enough to ripe that consumers can eat it within a few days. Cold storage is the primary tool. Researchers have demonstrated that holding Hass avocados in a cold chain, stepping down from about 5.5 °C to 4.5 °C over the course of roughly four weeks, significantly delays ripening. Combining cold temperatures with wax coatings and low-density polyethylene packaging extended shelf life by about two weeks compared to unprotected fruit.⁹

Modified atmosphere packaging pushes storage even further. By sealing avocados in bags that reduce oxygen levels and raise carbon dioxide, packers can slow the fruit’s metabolism and suppress fungal diseases like anthracnose, which is the dark rot that sometimes ruins an otherwise good-looking avocado. One approach using roughly 8 percent carbon dioxide and 2 percent oxygen cut anthracnose rates substantially during cold storage at 10 °C for 18 days, followed by ripening at room temperature.¹⁰ Under optimized conditions with sealed polyethylene bags at 5 °C, researchers have kept Hass avocados in good condition for up to nine weeks, far longer than the unpackaged fruit could survive.¹¹

That nine-week window is what makes it possible for an avocado picked in Peru in March to show up ripe in a European supermarket in May. Without these post-harvest technologies, the global year-round avocado supply would collapse. The fruit’s refusal to ripen on the tree, which is a nuisance in some ways, becomes an advantage here: because the clock doesn’t start ticking until the avocado leaves the branch, growers and shippers have a longer lead time than they’d get with most other tropical fruits.

Why “Avocado Season” Depends on Where You Live

If you’re shopping in the United States, the practical answer to “when are avocados in season” depends on which source country is supplying your store at any given time. Mexico ships to the U.S. all twelve months, with volumes peaking around the Super Bowl in late January and early February, when American guacamole consumption spikes. California’s harvest contributes most heavily from April through August. Peru and Chile fill in during periods when Northern Hemisphere supplies dip, primarily from late spring through early fall in U.S. calendar terms. Colombia, the Dominican Republic, and several other producers add smaller volumes at various points throughout the year.

The result is that avocados have effectively become a year-round fruit in the American and European retail markets, even though any individual tree follows a distinctly seasonal cycle. The overlay of hemispheres, altitudes, and microclimates across more than a dozen producing countries creates the illusion of a fruit without a season. But if you pay attention, you can sometimes taste the difference. Avocados harvested later in their region’s season, after months of oil accumulation on the tree, often have a richer, more buttery flavor than early-season fruit. The January California avocado has less fat and fewer carotenoids than the September one from the same grove, a difference that shows up on lab analysis and, for attentive eaters, on the palate as well.⁴

For backyard growers in mild climates, the local season is much simpler. A Hass tree in Southern California or a comparable subtropical zone will bloom in spring, set fruit by early summer, and produce harvestable avocados from roughly late fall through the following summer, with the exact window depending on how long you’re willing to let the fruit hang. The tree tells you nothing about ripeness by looking at the skin color while it’s still on the branch; maturity is determined by oil content or dry matter percentage, which growers track through periodic sampling. Home growers usually just pick one, bring it inside, and see if it ripens nicely within a week. If it does, the rest of the tree is ready. If the flesh stays watery and bland, the fruit needs more time.