Avocado
Persea americana · Perennial (tree)
Grown indoors in all USDA zones as a houseplant, whether or not it fruits. Seed-grown trees take about ten years to fruit; purchased trees three or four.
What it needs indoors
- Light
- Full sunMinimum 6 hours; south or west-facing window
- Water
- Let it dry outPrefers drier soil with high humidity
- Temperature
- 60–85°F
- Growing medium
- Free-draining potting mix
- Native range
- Cloud forest of south-central Mexico
- Difficulty
- Enthusiast
What usually goes wrong
Brown dry edges and tips on otherwise green leaves
Salt build-up in the mix, made worse by dry air. Avocado is unusually sensitive to the salts left behind by tap water and fertiliser.
Fix: Flush the pot every month or two: water heavily until it runs freely from the bottom, then let it drain right off. Filtered water or rainwater if your tap water is hard. Standing it on a pebble tray or grouping it with other plants raises the humidity around the leaves.
One bare stem with a tuft of leaves at the top
A seed-grown avocado runs straight up as a single leader for as long as it is allowed to, and nothing branches off it on its own.
Fix: Cut the stem back to about 6 inches once it passes a foot, then pinch the new tips each time they add a couple of sets of leaves. It feels drastic and it is the difference between a plant and a stick.
Leaves yellow and drop, stem soft where it meets the soil
Overwatering. Cloud forest means damp air over free-draining volcanic ground, which is close to the reverse of a heavy mix kept wet.
Fix: Free-draining mix, a pot only slightly larger than the rootball, and water only once the top couple of inches are dry. Raise the humidity around the leaves instead of the moisture at the roots.
