This one is for fun! If you are growing your plant from a stone taken from a supermarket avocado it is unlikely to be anything other than a decorative foliage plant. At any rate you'd have to be in it for the long haul if you want to eat avocados from your own tree. The trees take around 10 years to fruit. But it is still a lot of fun to see that giant seed sprout so why not have a go?
Indoor or Outdoor?
Avocado trees grow to 20m. They are a tropical fruit and hail from Mexico and Central America and as such they don't tolerate freezing temperatures. They can survive in the right site in the South of England but you are better off growing them in a large pot indoors.
You can buy avocado seeds or most common, just take the seed from your shop bought avocado. It will take from 3 to 8 weeks to germinate but development is rapid after that. You can start them in water or compost.
Planting In water
- Wash and pat the seed dry
- Find a jar with a neck wide enough to fit your seed in. An old jam jar would be perfect.
- Fill it with water nearly to the top.
- Wedge the avocado seed so that it sits at the top of the jar with the bottom touching the water. You can use 3 toothpicks or nails pressed gently into the seed to balance it or little pieces of wood or cork to wedge it in place.
- Put it somewhere warm - ideally a temperature of 20-25°C (68-77°F)
- Check it daily and top up so the base of the seed is kept in contact with the water.
You should see leaves and roots start to appear.
- You will need a well-drained 5" pot filled with potting compost. The Haxnicks Bamboo pots would be perfect. When the leaves and a reasonable amount of root has developed, carefully remove it from the jar and plant. so the seed is covered.
Planting in compost
There are two methods - use whichever you like depending on how much effort you want to put in (and how good you are at remembering a pot in the airing cupboard!)
- Soak the seed first in hot water for 30 minutes at 40-52°C (104-125°F)
- Cut a thin slice from the pointed end off the seed
- Sow in a pot of moist sandy compost with the cut end slightly above the soil surface and keep warm - around 20-25°C (68-77°F)
- place the seed in a pot, and cover it completely. Water well, allow to drain and leave in a warm, dark place, such as an airing cupboard.
- Check on the pot every week to ensure it is moist, and water if necessary.
- Once shoot start to show, move the pot to a sunny spot, such as a windowsill
Planting in the compost Heap
Bit of a strange one this one but the compost heap - if managed well - provides the ideal temperature and moisture level to germinate avocado seeds. So it might be worth experimenting by burying some avocado stones and retrieving and potting up any that sprout.
However you have grown it, when the stem reaches 15cm (6 in) tall, cut back by half. Once it has grown another 15cm (6 inches), pinch out the two newest sets of leaves to encourage bushy growth.
Apply a general pot plant feed every week to ten days during the spring and summer. You can feed less the rest of the year - around every six to eight weeks.
When roots appear through drainage holes, re-pot. This is likely to be needed yearly and is best done in the spring when the container is full of roots. The timing is very important for avocado plants as this is when they are set to grow.
This plant is not likely to do well long term so plan to have it for a few years and then start the fun again with a new seed. After two to three years you may start to see leaf discoloration which can't be remedied. One of the issues causing them not to fare terribly very well long term is the indoor atmosphere. One reason could be the lack of humidity so try keeping it somewhere humid if possible to extend its life.
Flowering & Fruiting
If your tree makes it to 1.5m tall then one trick to encourage the plant to flower is to treat the tree roughly. To do this attack the trunk of the tree with a knife or other sharp implement. Only cut the surface of the bark. You don't want to damage the tree too much or it won't grow properly. The stress brought on by this attack is said to panic the plant into flower, where it will then hopefully bear fruit.
You will to ensure that bees and other insects have access to your flowers so that they can pollinate them. So remember to leave the greenhouse or conservatory door ope in warmer weather and you may just get avocados!
Pests & Diseases
They are prone to a number of greenhouse pests such as Whitefly, Red Spider Mite and Mealybugs. They can also suffer from fungal leaf spots so watch out for these..