Germinating an avocado stone: our 3 easy methods

Growing an avocado from a stone is child's play!

Who hasn't enjoyed sprouting an avocado stone at school or at home? This fun activity has taught us from a young age to understand the germination process of plants. It's also a way to get an avocado tree for free, although those purchased from nurseries or garden centres are generally from seeds that are grafted to obtain specific varieties.

Here are three fun methods that work to grow an avocado tree indoors or in a conservatory in most regions.

growing avocado DIY — *The toothpick method*

Note: Spring or early summer are the best times for success with all three methods.

Method 1: The Toothpick Method

This is the classic method to ensure germination!

You will need:

1 ripe avocado
3 or 4 toothpicks
a clear, deep glass or container
room temperature water

Gently extract the stone from the avocado by cutting the flesh in half, and clean it with warm water (it should be perfectly smooth, without any flesh);
Optional: Soak it for 30 minutes in water at 35°C, then let it dry well. This helps soften the shell and facilitates germination;
Insert the toothpicks about 1 cm from the base of the stone (the widest and flattest part), spacing them evenly;
Place the stone on the glass so that only the base is submerged in water; the pointed part should remain at the top, suspended, without touching the water. This allows the base, from which the roots will emerge, to be in contact with the water while preventing the stone from rotting;
Put the glass in a bright location, but out of direct sunlight, and away from drafts. The ideal temperature for germination is between +20°C and +25°C;
Change the water every 5 days;
After 3 to 6 weeks, the stone will eventually split in two, allowing the future roots and stem to grow.

When the roots are about 7-10 cm long and one or more stems bear the first leaves, transplant the stone, removing the toothpicks, into a pot filled with very light potting soil: only the roots should be buried, with the stone remaining visible and protruding from the soil.

Water regularly, keeping the substrate always moist. At this stage, it is beneficial to pinch the main stem after a few weeks, above the first leaves, to encourage the avocado tree to branch out and to prevent the plant from growing a single long stem (this should also be done for the other two techniques).

Method 2: Germinating the Avocado with Cotton

Less commonly used than the previous method, but more effective than planting in soil, the plastic bag method offers a high success rate due to the greenhouse effect it creates. This process, often using cotton, is particularly useful for maintaining a constant humidity around the stone, which promotes germination.

You will need:

1 ripe avocado
1 airtight plastic bag (a large freezer bag, for example)
water-loving cotton or a good handful of potting soil

Moisten a piece of cotton (or a large handful of potting soil) and place it at the bottom of the bag;
Place the avocado stone on top, ensuring the pointed end is facing upwards;
Seal the bag without squeezing out all the air, to avoid excess stagnant moisture;
Place the bag in a warm, dark location to encourage germination;
Check regularly to ensure the potting soil remains moist, but not soggy: germination will occur with this method;
After a few weeks, usually between 3 and 6 weeks, you will see the stone split and roots starting to grow;
Once the roots are well developed and a shoot begins to appear, transfer the stone (gently removing the cotton) into a pot with potting soil, in a bright location to encourage plant growth.

Method 3: Planting the Stone in Soil

You can also try directly planting the stone in a pot filled with soil. However, this method is somewhat less easy to succeed than the other two.

The necessary materials

1 ripe avocado
A pot with a diameter of 15 cm
Potting soil + sand (or turf, perlite, coconut fibre), or a potting mix for citrus trees.

Extract the stone from the avocado by cutting it in half, and clean it with warm water;
Let the stone dry for a few days;
Fill the pot with a mixture of potting soil and turf (or if not available, sand, perlite, coconut fibre, or well-decomposed compost), leaving 2 cm of space below the rim of the pot;
Lightly compact the soil;
Place the stone in the centre, pointed end up, leaving it half buried;

Water generously: the soil should be well soaked;
Place the pot in a bright location, but out of direct sunlight;
Monitor daily and water every 3 days to keep the soil moist.

The stone usually splits between 4 and 8 weeks: a shoot appears at the centre of the two halves. We recommend transplanting into a slightly larger pot once the plant has established itself with a few leaves, to give it more space to grow.

For growing the avocado tree, check out Leïla's tips in How to grow avocado in a pot?, as you will likely cultivate this exotic plant in a greenhouse, heated conservatory, or indoors, since it does not tolerate temperatures below +10°C (it is only suitable for open ground in the so-called orange zone, which includes Mediterranean regions).

Also, read our tutorial on repotting the avocado tree!