Correct site selection is the biggest influencer of the success or failure when growing avocado trees. They grow best in a warm situation with fertile, well-drained soil in full sun and need protection from both strong winds and frost while the plants are young. Once they are established the trees can withstand frost to -2C or -3C.
Avocado trees need a good-sized area to grow. If left to their own devices they will eventually (after about 15-20 years) grow to a tree of about 10-12 metres high and 4-6 metres wide.
For those who are keen, avocado trees grow easily from seed but the downfall is they will take up to 10 years to fruit. Trees that are grafted will produce fruit after about four years and after seven years should be producing 200 or more avocados annually.
Many homes do not have a spot large enough to have a tree of this size but by pruning each year, a much smaller tree can be maintained. Intensive planting and pruning is now being practised by new commercial plantings, where the traditional tree spacing of 10 metres is now being halved to about 5m.
Skilled pruning is undertaken to keep trees maintained at 3-4 metres high, while not removing the trees’ ability to fruit.
This means fruit production is far closer to the ground, reducing the labour input needed at the time of harvest. The high labour input to extract fruit from tall trees is one of the contributing factors to the high cost of avocado fruit relative to other fruits.
Many people know the avocado variety Hass and to a lesser extent Reed, which are sold widely.
There are also other varieties that should also be considered for the home garden.
By planting several different varieties you will not only increase the flower pollination with better fruit set, but you will also have fruit through many months of the year as the varieties ripen at different times.
The varieties
Hass
New Zealand’s favorite avocado, crocodile-skinned, tasty fruit, heavy cropper, fruit mature from September to March, A-type flowering pattern, cross-pollinated by Fuerte or Bacon.
Reed
Large cannonball fruit, heavy cropper and very nutty flesh, fruit mature from February to June, A-type flowering pattern, cross-pollinated by Hashimoto, Fuerte and Bacon.
Fuerte
Very vigorous green-skin avocado with some cold tolerance, fruit mature from September to December, B-type flowering pattern, cross-pollinated by Hass or Reed.
Bacon
A smooth-skinned green avocado, with fruit maturing July to September, B-type flowering pattern, cross-pollinated by Hass or Reed.
Zutano
More cold-hardy than Hass and the earliest to fruit, ripening in July and August. Fruit has a fibrous texture with a higher water content and a lower fat/oil content. Yields well, with thin-skinned pear-shaped fruit resembling Fuerte. B-type flowering pattern.
Sharwil
Creamy with a mild, rich flavour, not as nutty as Hass. Oval-shaped fruit similar to Fuerte, the skin is hard. A major commercial variety in Hawaii due to its high quality and exceptional flavour and a smaller stone than other varieties.
It fruits for a long time, starting prior to Hass in about August and overlaps with Reed into February. B-type flowering pattern.
Cleopatra
Medium-sized, pear-shaped black fruit with a shiny skin. Yellow, creamy flesh of creamy, rich flavour.
The skin turns black prior to harvest. Larger than Hass fruit. Harvest from July to December. The tree is dwarf in size, growing about 3m high by 3m wide and compact and bushy in habit. B-type flowering, cross pollination with Hass and Reed will improve fruit set.
Gareth Carter is General Manager of Springvale Garden Centre.
