Commercial Growers FAQs

Commercial Growers FAQs

What are the best conditions for growing avocados?

The three most important things needed are:

1.Free draining soils. There are many soils which satisfy this from sandy soils, to volcanic clays, to ash and many in between. If in doubt, dig a hole 600mm deep, fill with water and ensure it is empty within 12 hours.

2.Temperature. Nowhere in New Zealand is too hot but many locations which are too cold. If you get temperatures below minus one, then it is going to be difficult to get trees established. Young trees need to be well sheltered.

3.Water. New Zealand is one of the few countries in the world where there is commercial growing without irrigation. However, in a drought trees will struggle and do much better with a timely drink.

There are many different rootstocks - which is best for me?

Rootstocks need to be divided into seedling root stocks (grown from a seed and then grafted), and clonal rootstocks (grown from a cutting and then grafted). We try and match the correct rootstock for different sites and soil conditions, so it is worth contacting our sales team who can advise. Please be aware that most clonal rootstocks are protected plant material, so are only available to members of NZ Avocado. For more information see our rootstock summary

Do I need to plant polliniser trees?

We recommend planting at least 11% Type ‘B’ flowering cultivars. In colder than average springs, polliniser trees are hugely beneficial as cross-pollinated fruit are less likely to abort; this results in heavier crops. 11%, is one in nine trees and this should be arranged as the centre of a noughts and crosses pattern. This ensures that every Hass is next to a polliniser. We also recommend a variety of polliniser cultivars, as this also increases your chances of a successful fruit set. Often pollinisers are pruned differently, so they might be 11% of tree numbers, but only 5% of canopy area

When is the best time to plant?

This depends on where you are and what access you have to water. Firstly, avocados like to be planted into a warm soil, so in much of the country that would mean from October through until early autumn. If you still get frosts in October, then delay until the possibility of one has passed. As soils dry out you will need to water/mulch to maintain a reasonable soil moisture. (DO NOT over water). We have growers planting from September to May, so keep to the above principles and find what works for your situation

What spacing should I use when planting my trees?

I could write pages on this subject as I have watched the industry evolve. Only ten years ago everyone used to grow big trees. There are many problems with this. They are impossible to shelter, hard to spray effectively, very difficult and expensive to pick, to mention just a few.

The modern trend in all tree crops is to plant more intensively, and avocados are no exception. This means a spacing of between 6 x 4 (meaning 6 metres between rows and 4 metres between trees within a row) to 5 x 3. There are many advantages planting closer, one of the main one being reaching full production years earlier than wider plantings. For more information on high density spacings

Should I prune my trees?

Avocados, like most trees like to be pruned. It helps maintain trees to the desired size and also helps them maintain youthful vigour. It’s important not to cut off all of next years flowering wood, so make one or two big cuts rather than many cuts right around the tree. For more information on pruning high density plantings.

What fertiliser should I use?

With the oil content in the fruit being very high it takes a lot of nutrients to grow avocados. We recommend fertilising little and often with a high nitrogen fertiliser while the trees are getting established.  After the first year we recommend doing and annual soil and leaf test so a fertiliser programme can be specially targeted for your trees.  Your consultant will be able to advise you on the best fertiliser programme to use based on these test results.

Should I mulch my trees?

Mulch is great for avocados. Ensure it is well composted to avoid nitrogen draw down. Most organic material will work, but avoid anaerobic materials like lawn clippings as this may suffocate trees. Ensure the mulch is not touching the trunks of young trees as this can cause stem rots.

How long will it take for my trees to fruit?

You can expect some fruit in year three. As the trees grows, the number of fruit will grow!

How big do avocado trees grow?

Left to their own devices, trees can get to 15 metres tall. Tree size can be controlled with pruning.

Can I over water my trees?

Absolutely. Far more damage is done over watering than under watering. Water deeply, but no more than once a week.

Should I stake my young trees?

You need to avoid any root damage to your trees so a stake to avoid too much tree swaying is vital. Remember to check any stake ties that may strangle the trees as they grow

Do I need to spray for pests and diseases?

There are several pests and diseases that must be controlled, and some may start attacking your trees the day you plant them. Some will target leaves, some fruit and some roots. Pay particular attention to six spotted mite, Fullers rose weevil, leafroller caterpillar, thrip and Phytophthora. Your horticultural merchant can advise on suitable products.

I’ve heard about injecting avocado trees. Do I need to do this to my young trees?

Phosphorous acid is an effective tool to supress Phytophthora and is one of the ways available to fight it. It can be sprayed on young trees or injected when trees get to three years old. There are many other tools for fighting Phytophthora including using tolerant rootstocks, improving drainage and soil structure, the use of mulches and effective moisture management.

How do I apply for a PPin to be able to buy clonal rootstock trees?

You will need to PPin (which is a Personal Identification Number issues by NZ Avocado) to purchase any protected plant material. To apply for a PPIn contact NZ Avocado on 0800 AVOCADO.

How do I find out more?

Part of the package we offer at Lynwood is advice on where and how to grow. We often visit orchards, or potential sites so we can help growers with the early fundamental decisions. We are very aware that when growers are making their most important decisions (potential sites, root stocks and spacing), is when you know the least. We can and want to help.