Gardening – Growing green gold

Avocados have been in the news a fair bit lately; a record high fruit price, thieves raiding orchards and more information about just how good this fruit is for your health, all point to increasing popularity and consumption of this superfood.

Avocado trees are actually not too difficult to grow in your backyard, and once in production, will give you fruit for nine to 10 months of the year if you pick a few each week (or plant both hass and reed varieties and have fruit all year round). They are a very attractive tree, with glossy subtropical leaves and a rounded shape. However, there are a few important factors to get right for successful avocado growing.

Firstly, they are a forest margin tree, often one of the first colonisers after a forest giant has fallen, so they need lots of light and lots of mulch. Avocados are probably the fussiest fruit tree in regards to soil quality, as they need moist but very well-drained soil that has plenty of organic matter.

A good solution on heavy or wet soils (which includes most of our region, except the volcanic soils around Mangawhai and the sandy loams at Tapora) is to plant on a mound. Simply place the root ball on the ground, then build up around it with good quality, free-draining topsoil, to a radius of about a metre and a depth in the centre of about 30 to 50cm. If you want to be extra sure, increase the radius and depth.

Then, throughout the year, but particularly in early spring when the soil is at its wettest, pile loads of mulch around the tree; building up a layer at least 30 to 50cm high. This mulch layer extends out 20 to 30cm past the drip line (the edge of the tree), as this is where most of the active feeder roots are found. The feeder roots will move up out of reach of moisture loving diseases and into the oxygen, microbe and nutrient-rich mulch layer. The mulch also keeps the soil moist and cool through the summer; helping maintain root health. Woody mulches are best, which is handy as I find my avo tree is a good place to deposit any twiggy prunings, palm fronds and stalky material that is a pain to dispose of elsewhere.

Finally, once your tree is well underway, you’ll probably notice that it is getting rather big! I’ve seen 90-year-old avos that are four storeys high and nearly as wide, so unless you live on a farm, this probably won’t be ideal. Fortunately, avos are easy to prune. Just cut off any limbs that are growing too upright and head back any that are taking up too much space. Within a year, regrowth will hide the ugliness and the increased light will give you more fruit on the lower branches, which are easier to pick anyway. Happy eating!