Tree · Lauraceae
Avocado
Persea americana
Give it full sun, sharp drainage, and shelter from frost, and an avocado can shade a yard for decades.
Full sun
Every 3–7 days
USDA 9–11
30–66 ft · 9–20 m
Overview
The avocado is a broad evergreen tree from the laurel family, native to the warm uplands of Mexico and Central America. It grows tall and wide, reaching well over 65 feet (20 m) in the open ground, with shallow roots and brittle wood that ask for room and a sheltered spot. The fruit is the draw, a buttery, fat-rich pick that ripens off the tree rather than on it.
Growers split avocados into three races. The Mexican race is the most cold-hardy, the West Indian race wants true tropical heat, and the Guatemalan race sits in between, and that lineage decides how much frost a given tree will take. Most named cultivars carry blood from more than one race.
An avocado is a long game. Trees flower in two patterns, type A and type B, and the two opening on different schedules is what gives pollination a boost. Plant one, keep its feet dry and its crown out of the frost, and it can feed a household for years once it finally settles into bearing.
Care
The short version: full sun and fast-draining soil are everything, since soggy ground is what kills avocados. Water deeply but let the top half dry between drinks, shelter young trees from frost, and feed through the growing season.
Light
Avocados want full sun, ideally six or more hours of it a day. They'll take a little partial sun, but a tree in real shade grows lanky and sets far less fruit.
Water
Water deeply but not often, then let the top half of the soil dry before the next soak. Young and fruiting trees need steady moisture, yet avocados hate wet feet, and waterlogged ground is what invites the root rot that kills them.
Soil
Give them deep, well-drained sandy loam that never stays soggy. A pH between 6.0 and 7.0 suits them, and where drainage is poor, planting on a raised mound makes all the difference.
Temperature
Avocados grow happily from about 23°F to 95°F (-5°C to 35°C), though the cold end depends heavily on the race. Frost-tender types are damaged well before the Mexican-race trees, so match the cultivar to your winters.
Humidity
Average humidity, in the range of 40% to 60%, keeps a tree comfortable. They aren't fussy about moisture in the air, so there's no need to fuss over it outdoors.
Feeding
Feed monthly through the spring-to-fall growing season with a balanced fertilizer that carries nitrogen plus micronutrients. Avocados lean especially on zinc and iron, and a shortage of either shows up fast in the leaves.
Pruning
Avocados need little cutting. Take out dead, diseased, or crossing branches and lightly head back after harvest to hold the height and shape, but skip heavy pruning, which only costs you fruit.
Repotting
Avocados are almost always grown in the ground, so repotting rarely comes up. A young container tree can be potted up every 2 to 3 years until it goes into its permanent spot.
Size & spacing
This is a big tree, climbing from 30 to 65 feet (9 to 20 m) tall with a spread to match. Plant it well clear of buildings, foundations, and power lines, and give the brittle, shallow-rooted crown all the room it needs.
When to plant
Avocados run on warmth and won't forgive a hard freeze. Set young trees out in spring once the frost danger has passed and the soil has warmed, expect bloom from late winter into spring, and harvest the fruit off the tree across several months depending on the cultivar.
Northern hemisphere
Southern hemisphere
Typical months for a temperate climate: start earlier in warm zones, later where spring frosts linger.
- Sow: Seed can be sprouted indoors year-round in warm conditions, but named cultivars are grafted rather than seed-grown.
- Plant: Spring, after danger of frost has passed and soil has warmed.
- Harvest: Flowers late winter to spring; fruit matures on the tree and is harvested over several months depending on cultivar (e.g., Hass roughly summer to winter).
Hardiness
USDA hardiness zones: 9–11
Temperature: down to -7°C
Troubleshooting
Most avocado trouble starts underground or after a cold night, and it shows in the leaves first. Read the canopy early and you can act before a tree slides into decline. Match what you see below, then move while it still helps.
Pale, wilting leaves and a canopy that keeps thinning
This is Phytophthora root rot, the disease that kills more avocados than any other. The fungus rots the fine feeder roots in soggy ground, so the tree starves and wilts even when you keep watering. Fix the drainage first, ease off the water, and dig in coarse mulch kept clear of the trunk.
Fix:
- Improve drainage and stop overwatering
- Apply phosphite (phosphonate) treatments
- Replant or topwork onto tolerant rootstocks using certified disease-free stock
- Maintain coarse wood-chip mulch kept several inches off the trunk and apply gypsum
Scorched, blackened leaves after a cold snap
This is frost damage, and the West Indian and Guatemalan types take it worse than the hardier Mexican race. A freeze blackens the tender new growth and burns the leaf edges, and shoots can die back. Wrap and cover young trees through a freeze, then wait until spring growth returns before you cut away the dead wood.
Fix:
- Protect young trees with covers, trunk wraps, and overhead irrigation during freezes
- Prune frost-damaged wood only after new growth resumes in spring
Brown, crispy tips and edges on the leaves
Browning that creeps in from the tips and margins is salt tip burn, where chloride and sodium build up from salty irrigation water or too much fertilizer. It shows up worst in the dry season. Flush the salt down past the roots with a deep, slow soak and cut back on the feed.
Fix:
- Leach the soil with deep irrigation
- Reduce fertilizer rates
- Switch to lower-salinity water where possible
Toxicity
The ripe flesh is the food, but the rest of the tree is a real hazard. Leaves, bark, fruit, and the big pit all hold a compound called persin, which is dangerous to horses, livestock, and above all birds, and can sicken cats and dogs. Keep grazing animals and pet birds well away, and clear up any fallen fruit.
Toxic to
Cats · Dogs · Horses · Rabbits · Livestock · Birds
Safe for
People
Cats Mild
A cat that nibbles avocado usually gets off lightly, with some vomiting or loose stool from the persin. The real worries are the rich fat, which can set off pancreatitis, and a swallowed pit large enough to lodge in the gut.
Dogs Mild
Most dogs shrug off a small taste with little more than an upset stomach. Watch the fatty flesh, which can bring on pancreatitis, and keep the pit well out of reach, since a gulped seed can choke a dog or block the bowel.
Horses Severe
Horses are hit hard by persin. The classic sign is a swollen, puffy head and neck, often alongside colic, and a serious dose can turn dangerous. Keep them away from the leaves, bark, and dropped fruit.
Rabbits Toxic
Persin makes every part of the plant unsafe for rabbits, so none of it belongs in the hutch or run. Keep leaves, bark, and windfall fruit out of reach entirely.
Livestock Severe
Goats, sheep, cattle, and donkeys all suffer badly, developing the same swollen head and neck and risking heart and lung damage. Nursing animals can also come down with mastitis, so fence stock away from the tree and clear any fallen branches.
Birds Severe
Birds are the most fragile of all and can die from even a little. Expect weakness, a droopy, agitated mood, ruffled or pulled feathers, and labored breathing before the heart fails. Never offer any part of an avocado to a pet bird.
People Flesh safe
The ripe flesh is the part people eat, and it's a healthy, everyday food. The leaves, bark, and skin aren't meant for eating, and a small child should be kept from gnawing on the hard pit.
Keep fallen fruit, pits, leaves, and prunings away from pets and livestock; never feed any part of an avocado to pet birds.
Helpline numbers
United States
ASPCA Animal Poison Control: (888) 426-4435 (fee applies)
Poison Control: (800) 222-1222
Canada
Poison Centres: 1-844-764-7669
Varieties
A handful of cultivars cover almost every avocado you'll meet, set apart by flower type, skin, and how much cold they shrug off.
Hass
A type A cultivar that makes up about 95 percent of California's commercial crop, with pebbly skin that turns black as it ripens and a parentage traced to a single 1935 patented tree.
Fuerte
A type B cultivar of Guatemalan and Mexican parentage with smooth green skin that was the standard market avocado before Hass took over.
Mexicola
A Mexican-race cultivar prized as one of the most cold-hardy, bearing small fruit with thin, dark skin you can eat.
How to propagate
Avocados spread two ways, and they could hardly be more different: a quick, unreliable pit on a windowsill, or a skilled graft that copies a named variety exactly.
GraftingDemanding
Spring, during warm weather when the bark slips and growth is active · Grafted trees typically bear in 3-4 years
Grafting is how every named avocado is made. In spring, when the bark slips and the tree is in active growth, growers cleft- or tip-graft a cultivar onto a seedling rootstock, which keeps the fruit true to type and brings a crop in about 3 to 4 years. It takes a steady hand, but it's the only way to copy a variety like Hass.
SeedEasy
Any time in warm conditions · 5-13 years to fruit, if at all
Sprouting a pit is easy and works any time the weather stays warm, but the result is a gamble. A seedling is genetically variable and may take 5 to 13 years to fruit, if it fruits at all, which is why growers mostly raise seedlings as rootstock rather than for the fruit itself.
Myths
Every avocado is deadly poison to dogs and cats.
In dogs and cats the persin in the flesh usually causes nothing worse than a mild stomach upset. The bigger risks are pancreatitis from the rich fat and a swallowed pit that can choke or block the gut. Birds, horses, and grazing livestock are the ones in real danger.
A pit grown in a glass of water gives you fruit just like the parent.
A seedling avocado is a genetic toss-up and may take 5 to 13 years to fruit, if it ever does. Named cultivars like Hass are grafted so they fruit true to type and far sooner.
One avocado tree is all you need for a good crop.
Avocados carry two flower types, A and B, and pairing a type A tree with a type B improves pollination and fruit set. A lone tree can still bear some fruit, just less reliably.