Avocados do really well here in Northland, if the soil and drainage is just right. You see, as fantastic as avocados are, they can also be a bit fussy but, with a bit of love and attention, they will fruit just fine. Avocados despise "wet feet", so improve drainage of your heavy clay soil with gypsum and compost well before planting, and consider planting your avo's on a slope, or a mound.
Choose a warm, frost-free position for these tasty trees, remembering that many avocados can reach a height of 5 – 10m at maturity, so leave room for these gorgeous trees. Over the hot summers you may find your avocado looking a bit average, especially in its first few years. Avocados aren't known for their vigorous root systems, and this can cause them to dry out much quicker than many other plants, so keep the water up to them when it's really hot.
The other thing to remember about avocados is that each variety has a different flowering "habit", which sees avo's categorized into two groups, A and B. Now, avocados are partially self-fertile, which means they may produce a bit of fruit on their own, but their yields will be increased if you can put in one tree of each group.
Avocado – Bacon (B Flowering Variety): The best cold tolerant avocado, Bacon will grow to a manageable height of 4m in cooler climes. Fruit is a medium size and quality and appears on the tree from June – late July, and, unlike most other avocados, will fall from the tree when ripe. Can bear fruit in as little as four years.
Avocado – Fuerte (B Flowering Variety): Another great cold tolerant variety, Fuerte produces small, pear-shaped fruits with a dark green skin and a fabulous nutty flavour. Fuerte can be quite a large, spreading tree reaching a decent height of about 8m x 12m, so give it some space. Fuerte has a tendency to produce fruit every second year (between June and October), and can take about six years to produce fruit.
Avocado – Hass (A Flowering Variety): Possibly the most popular of all avocados, Hass bears incredibly flavoursome fruits that keep well. A handsome tree to about 9m x 10m, Hass is fairly cold and frost tolerant once established, and will bear its delicious fruit between September and January.
Avocado – Reed (A Flowering Variety): Large, round, thick-skinned variety with a smooth, green skin and a rich flavour. Reed avocados store well in the fridge once cut. This variety grows to a manageable 4m x 2m, and will bear fruit after three years or so. Fruit matures between November and March.
A word of warning regarding all avocado types – many parts of the plant can be highly poisonous to some animals, mainly horses, cattle, goats and birds.