Tree · Lauraceae
Avocado
Persea americana
Offer it full sun, sharp drainage, and a little frost shelter, and your avocado can shade the yard for decades.
Full sun
Every 3–7 days
USDA 9–11
30–66 ft · 9–20 m
Overview
The avocado is a generous, broad-canopied evergreen from the laurel family, with roots in the warm highlands of Mexico and Central America. Given open ground it stretches tall and wide, climbing well past 65 feet (20 m), though its shallow roots and easily snapped wood mean it appreciates room and a sheltered corner. The prize is the fruit, buttery and rich, and the lovely quirk is that it ripens after you pick it rather than on the branch.
Avocados fall into three races, and knowing yours takes a lot of the guesswork out of winter. The Mexican race shrugs off the most cold, the West Indian race craves real tropical warmth, and the Guatemalan race lands somewhere between the two, so that ancestry quietly sets how much frost your tree can stand. Most named cultivars mix more than one race, which is nothing to fret over.
An avocado rewards patience more than haste. Its flowers come in two patterns, type A and type B, and because the two open on different timetables, pollination gets a friendly nudge. Plant one, keep its feet dry and its crown out of the frost, and once it settles into bearing it can feed your household happily for years.
Care
The short version: what your tree really wants is full sun and quick-draining soil, because soggy ground is the one thing that truly undoes an avocado. Water deeply, then let the top half dry before you water again, tuck young trees in against frost, and feed gently through the growing season.
Light
Your avocado will be happiest in full sun, ideally six or more hours each day. A bit of partial sun is fine, but a tree left in real shade tends to grow leggy and gives you much less fruit, so the brighter the better.
Water
Water deeply but sparingly, then let the top half of the soil dry out before the next good soak. Young and fruiting trees do want steady moisture, yet avocados truly dislike wet feet, and it is waterlogged ground that opens the door to the root rot that takes them down.
Soil
Give your tree deep, well-drained sandy loam that never sits soggy, and it will reward you. A pH between 6.0 and 7.0 is just right, and if your drainage is on the poor side, planting on a raised mound makes a world of difference.
Temperature
Avocados are comfortable from roughly 23°F to 95°F (-5°C to 35°C), though how much cold yours will take depends a great deal on its race. Frost-tender types suffer well before the Mexican-race trees do, so it pays to match the cultivar to your winters.
Humidity
Ordinary humidity, somewhere around 40% to 60%, keeps a tree perfectly content. They really are not picky about moisture in the air, so once it is outdoors there is no need to worry yourself over it.
Feeding
Feed once a month through the spring-to-fall growing season with a balanced fertilizer carrying nitrogen and micronutrients. Avocados lean hard on zinc and iron in particular, and if either runs short the leaves will let you know fairly quickly.
Pruning
Happily, avocados ask for very little cutting. Take out any dead, diseased, or crossing branches and head back lightly after harvest to keep the height and shape in check, but go easy, since heavy pruning only trims your fruit.
Repotting
Since avocados nearly always grow in the ground, repotting hardly comes up at all. A young tree in a container can simply be potted up every 2 to 3 years until the day it moves into its forever spot.
Size & spacing
This is a big, generous tree, rising from 30 to 65 feet (9 to 20 m) with a spread to match. Plant it well clear of buildings, foundations, and power lines, and give that brittle, shallow-rooted crown all the elbow room it could ask for.
When to plant
Avocados love warmth and won't take kindly to a hard freeze, so timing is your friend here. Wait to set young trees out until spring has chased off the frost danger and the soil has warmed, look for bloom from late winter into spring, and gather the fruit off the tree over several months, depending on which cultivar you grow.
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
Almost every avocado worry begins down at the roots or after a chilly night, and the leaves are usually the first to tell you. The good news is that an early look at the canopy gives you plenty of time to help. Find your tree's symptom below and step in while it still makes a difference.
Pale, drooping leaves and a canopy that keeps thinning
What you are seeing is Phytophthora root rot, the trouble that claims more avocados than anything else. In soggy ground the fungus quietly rots the fine feeder roots, so your tree starves and wilts even as you keep watering it faithfully. Sort out the drainage first, ease back on the water, and work in coarse mulch kept well 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
Blackened, burnt new growth after a freeze
This is frost damage, and the West Indian and Guatemalan types feel it more sharply than the tougher Mexican race. A freeze blackens the tender new growth and singes the leaf edges, and whole shoots can die back. Wrap and cover young trees through a freeze, and wait patiently for spring growth to return before you trim 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
Browned, crisp leaf edges and tips
Browning that creeps in from the tips and margins is salt tip burn, where chloride and sodium gather from salty irrigation water or a heavy hand with fertilizer. It tends to look worst in the dry season. Flush the salt down past the roots with a slow, deep soak, and lighten up 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 wonderful to eat, but it helps to know the rest of the tree is not so friendly. The leaves, bark, fruit, and that big pit all carry a compound called persin, which is genuinely dangerous to horses, livestock, and most of all birds, and can make cats and dogs unwell. Keep grazing animals and pet birds at a safe distance, and gather up any fallen fruit so nobody is tempted.
Toxic to
Cats · Dogs · Horses · Rabbits · Livestock · Birds
Safe for
People
Cats Mild
A cat that nibbles a little avocado usually comes through fine, with maybe some vomiting or a loose stool from the persin. The real things to watch are the rich fat, which can stir up pancreatitis, and a swallowed pit big enough to lodge in the gut.
Dogs Mild
Most dogs brush off a small taste with little more than a queasy stomach. Keep an eye on 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 take persin hard. The telltale sign is a swollen, puffy head and neck, often with colic alongside, and a serious dose can turn dangerous. Keep them well away from the leaves, bark, and any dropped fruit.
Rabbits Toxic
Persin makes every part of the plant unsafe for rabbits, so none of it should reach the hutch or run. Keep leaves, bark, and windfall fruit entirely out of reach.
Livestock Severe
Goats, sheep, cattle, and donkeys all suffer badly, developing that same swollen head and neck and risking heart and lung damage. Nursing animals can also develop mastitis, so fence stock well away from the tree and clear off any fallen branches.
Birds Severe
Birds are the most delicate of all and can die from even a small amount. Look for weakness, a droopy, restless mood, ruffled or pulled feathers, and labored breathing before the heart gives out. Never offer any part of an avocado to a pet bird.
People Flesh safe
The ripe flesh is the part people enjoy, and it is a healthy, everyday food. The leaves, bark, and skin are not meant for eating, though, 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
Just a few cultivars account for nearly every avocado you'll ever meet, and they are easy to tell apart by flower type, skin, and how much chill they can handle.
Hass
A type A cultivar that accounts for about 95 percent of California's commercial crop, with pebbly skin that darkens to black as it ripens and a family line traced back to one patented 1935 tree.
Fuerte
A type B cultivar of Guatemalan and Mexican parentage, with smooth green skin, that was the market's go-to avocado before Hass came along.
Mexicola
A Mexican-race cultivar treasured as one of the most cold-hardy, carrying small fruit whose thin, dark skin is good to eat.
How to propagate
There are two ways to start an avocado, and they could hardly feel more different: a fun, hit-or-miss pit on the windowsill, or a careful graft that copies a named variety to the letter.
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 comes to be. In spring, when the bark slips and the tree is in active growth, growers cleft- or tip-graft a chosen cultivar onto a seedling rootstock, which keeps the fruit true to type and brings a crop in about 3 to 4 years. It does take a steady hand, but it is truly 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, though the outcome is a gamble. A seedling varies genetically 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
Any avocado will fatally poison a cat or dog.
In dogs and cats the persin in the flesh usually amounts to nothing worse than a mild tummy upset. The bigger worries are pancreatitis from the rich fat and a swallowed pit that can choke or block the gut. It is the birds, horses, and grazing livestock that face the real danger.
Root a pit in a jar of water and it will fruit exactly like its parent.
A seedling avocado is a genuine genetic surprise 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 a good deal sooner, which is why most growers go that route.
A single avocado tree by itself will crop just fine.
Avocados carry two flower types, A and B, and pairing a type A tree with a type B lifts pollination and fruit set. A single tree can still set some fruit on its own, just less dependably, so do not feel you have failed if you only have room for one.