Horticulture Magazine

How To Grow An Avocado Stone In 6 Steps

an avocado sliced in half showing its stone

The avocado is a delicious fruit jam-packed with healthy fats and nutrients.

While a little tricky to grow in the UK, it’s not impossible – though your plant may never bear fruit.

Native to Central America, the avocado plant (Persea americana) thrives in hot, humid and sunny climes.

In the right conditions, they can grow up to a whopping 20 metres in height… but the UK is definitively not an environment conducive to those conditions.

an avocado stone sprouting

While it does require careful attention, a warm home and a stack load of patience, it’s not actually that challenging an endeavour once you get the hang of it.

For any budding horticultural enthusiasts keen to try their hand at growing this colourful plant, here’s a step-by-step guide to bringing an avocado plant to full maturity from the seed.

Happy growing!

1) Know your avocado

avocados on a supermarket shelf

While it is possible to coax a standard Hass avocado that you’d find in your local supermarket to life from its seed, this strain of the species is pretty much guaranteed that it will never bear fruit for you.

That’s because Hass avocadoes are more comfortable in the sultry climes of Southern California, so a switch to the British climate won’t bring much more than attractive foliage. [source]

As mentioned above, fruit-bearing avocado plants in the UK are rare – but not unheard of.

If you are intent on encouraging your stone to eventually bear fruit, source a variety of the plant that’s hardier in nature and can withstand colder temperatures.

Despite also being bred in the scorching conditions of Florida, the Brogdon avocado is a more resilient type and can handle temperatures near freezing. [source]

2) Preparation

The next step is to prepare your avocado stone for the journey it is about to undergo.

Very carefully remove it from the fruit and clean it of any mushy residue, ensuring you don’t damage it or remove the brown skin from its surface.

stone sat in the empty shell of an avocado fruit

It may help if you soak the stone in a cup of cold water for a few minutes, before gently brushing off any fruit which may cling to its surface.

Next, locate which end of the seed is up and which is down.

The top is where the sprouts will shoot from and is generally pointier in appearance, while the bottom will spread roots and has a flatter contour.

an avocado in two halves on a white background
Top = pointy, bottom = flat

You need to know which is which so that you can position it correctly for the next step of the process.

3) Germination

Now, you want to encourage the stone to germinate.

everything needed to grow an avocado from seed

The best way to do this is to pierce it on four sides with cocktail sticks, creating a kind of scaffolding which will suspend the avocado in your chosen receptacle.

three cocktail sticks stuck into an avocado stone and balanced on the top of a glass of water

A glass or a plastic cup makes a great option for this, since it’s transparent and you can visibly see when the seed is beginning to sprout roots.

avocado stones germinating in 4 plastic pots

With the stone skewered, place it atop a cup filled with water so that the bottom of it is completely submerged, but the top is open to the air (as demonstrated above).

Over time, the water will become dirty and must be changed regularly (every five days or so) to prevent the spread of bacteria, mould and fungal growth.

the root of a part developed avocado seed

Eventually, you will notice the brown skin on the outer surface of the seed slough off, while a tiny crack will appear at its apex and spread all the way down to the bottom.

From the bottom, a teensy taproot will emerge, potentially branching into multiple prongs as it grows.

an avocado seed being grown on a windowsill with visible emerging root

This taproot must never be allowed to dry out or become unsubmerged!

The whole process varies from plant to plant, but generally takes at least two months to occur.

4) Potting

As the taproots appear at the bottom of the stone, so too will a sprout make its entrance from the top.

hand holding the roots of an avocado seed after being kept in water for weeks

When this sprout has turned into a stem around six inches tall, cut it back down to half its size to encourage new growth.

When it reaches six inches in height once more, it’s time to transplant it to soil.

Place it in a pot with a diameter of around 10 inches with plenty of soil that is rich in humus, leaving the upper surface of the stone exposed.

a propagated avocado seed after planting up in a soil container

Position your plant in a location that receives plenty of sunlight, since avocadoes thrive in warm conditions.

In the summer, it’s okay to leave them outdoors, but you must bring your babies inside as soon as the temperature begins to drop.

Water the plant frequently, treating it to an occasional soak, but ensure the soil doesn’t become saturated.

If the leaves begin to turn yellow, that’s a sure-fire sign that you’ve overwatered the plant.

avocado plant leaves in sunlight

In that case, leave it to dry out completely for a few days before watering again.

5) Patience!

Now it’s time to play the waiting game!

Cultivating an avocado plant to a fruit-bearing stage requires a lot of patience and careful maintenance, so keep an eye on its progress on a regular basis.

six stages of growth for an avocado seed

Once the stem reaches a foot in height, you should pinch out the upper foliage, thus encouraging it to grow more offshoots and become a bushier specimen.

Repeat that process every time the plant gains another six inches in height.

It’s likely that you might encounter a pest problem over the course of your plant’s life, since mites, aphids, flies and other bugs all can’t get enough of their brilliant green leaves.

avocado plant foliage from a birds eye view

If you do find you have a pest infestation, wash all the critters off the plant with a hose, then spray it with a combination of warm water, a small amount of washing up liquid and a teaspoon of neem oil.

This will ensure they don’t return – but if they do, simply repeat the process until they have been vanquished.

6) Pay-off?

an avocado plant in a small orange container sat on a windowsill

As we said at the outset, it’s a very tall order to produce fruit from an avocado houseplant, though it can certainly be accomplished.

Even if you are successful, it will take years to reap results; the quickest turnaround you can expect is three to four years, but some plants don’t bear fruit for 10 or even 15 years, while others never do!

As such, it’s a long game that you’ve engaged in.

If your plant does begin to bear fruit, it will require pollination.

To facilitate that process, it’s a good idea to grow several trees all at once, since they can provide pollinators with easy crossover options.

unripened avocado fruits sat on a table

But even if you do manage to pull off the remarkable feat of enticing avocados from your homegrown plant, remember that they will not resemble the fruit from whence the original stone came in the slightest!

Store-bought avocadoes are cultivated in industrial farms, where everything from the ambient conditions to the branches themselves are minutely controlled.

All the same, you should still have plenty of fun growing your avocado stone to full maturity regardless.

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