How and when to prune Phormium or New Zealand Flax


The genus Phormium, commonly known as New Zealand flax, comprises two species of perennial plants native to New Zealand Phormium tenax and Phormium cookianum. The Maori people called these plants as harakeke and wharariki respectively. Since among the uses that this ancient town gave to the Phormium was the use of fibers to manufacture clothing, baskets, fishing nets, etc., the Europeans baptized it as flax (despite the great differences that exist with the flax of the Northern Hemisphere ). Although his story is very interesting in this article, we will not study how to perform the pruning of Phormium or New Zealand flax.


Although there are two species that we will be talking about (Phormium tenax and Phormium cookianum) we will generalize using only the term Phormium. This is because the treaty to prune one or another species is the same.

Note: Please note that the advice given here is general, this blog is consulted from many countries in the world, with totally different characteristics, what not all tips will be adapted in the same way in all cases. Once you finish reading the article it will be necessary to analyze all the information and apply what you have learned in the best way. If you have any questions, remember that you can contact us to make your inquiries.

1. How to care your New Zealand flax


Although the pruning of New Zealand flax is the central axis of this article, it does not stop being one of several of the caution that this bush needs to be healthy, strong and beautiful. In this section we will see the key care of Phormium.

  • Soil: The ideal soil for these plants must have very good depth and excellent drainage. As for its composition it is preferable that it is of the sandy type, adapting well to low nutrient soils that contain many stones, the most important thing is that they do not store water.
  • Location: Ideally, plant them in a place where they receive enough sun rays, so that their colors become even more intense.
 New Zealand flax
New Zealand flax – Image source
  • Climate: You can imagine that being native to New Zealand they grow better in areas that have oceanic climates, although they can usually adapt to any type of weather. On the other hand they can withstand temperatures of -6 and -10 ° C without any damage to their roots, as well as withstand the intense heat that occurs in the first months of the summer season.
  • Irrigation: Although in spring / summer they require regular watering, they are able to withstand dry periods thanks to their ability to store water in their tissue. The ideal way to water this type of plants is by dripping.
  • Pests: Although they are not prone to attack by pests, sometimes you can find attacks of cottony cochineal and snails.
  • Pruning: as every garden plant needs pruning, in what follows we will make it clear how and when to carry them out.

2. Tools needed for pruning Phormium


In the next sections we will see that pruning this plants is not complicated at all. And as often happens, easy pruning needs a small amount of tools.

In this case you can manage with simple hand pruning shears or a sharp knife, It is more in many occasions you can perform pruning with stationery scissors. Keep in mind that the moment you make the cut is ideal to transmit diseases from plant to plant, that is why you must disinfect the blades before pruning and every time you change the plant.

On the other hand, when we carry out gardening tasks like this, some basic safety implements never go wrong. These can be a pair of gloves and glasses, this will protect your hands and eyes from any sharp elements.

You may also be interested in knowing about pruning:

2.1 Needed care of cutting back tools

Try to perform the following care in your pruning tools to extend useful life.

  • Use the right tool for a job and avoid twisting or straining it.
  • Clean and oil tools regularly by wiping an oily cloth on blades and other surfaces.
  • Keep cutting edges sharp by regularly using an oilstone.
  • Wooden handles should be varnished or regularly treated with linseed oil to keep them from cracking or splintering.

Keep in mind that if you extend the life of your tools you will not be doing anything other than saving money. 😉

3. Pruning Phormium or New Zealand Flax


There are many reasons for the popularity of New Zealand flax in gardens around the world, high resistance to inclement weather, easy care, being perennial (something that brings green to your garden all year), great variety of size and colors , beautiful flowers, etc. Simply find a good place to locate it and the plant will beautify it without much attention.

Among the facilities granted in his care is the simplicity of his pruning. Unlike many plants that need different types of pruning throughout their life, the Phormium almost exclusively conforms to light cleaning pruning.

Let’s see below how and when to carry out these prunings in our New Zealand Flax.

3.1 How to prune

The foliage of the New Zealand Flax stays green throughout the year, being able to change hue depending on the time, degree of sun exposure and species. This green color can be damaged by the change to a brown hue or appearance of spot spots, this greatly damages the aesthetics of the plant and can be due to many reasons, among which we can mention:

  • Small spots may be due to water droplets if you have watered on a sunny day, so when watering it is much better to water early in the morning or at sunset.
  • In case of severe attacks of cochineal, the leaves may tend to discolor and have some spots.
  • Long periods of intense cold.
  • As we make clear the Phormium need soils with good drainage, otherwise an excessive irrigation can cause damage to the leaves.
Pruning Phormium
Pruning Phormium

These and other reasons may force you to trim all those leaves and stems in poor condition. It is there where you will have to look for a pruning shears or knife (as you prefer) and start pruning tasks in your Phormium.

You must trim all these leaves in poor condition from the base of the plant, this will encourage the plant to develop new leaves when spring begins. It may be the case that before a winter more crude than usual the whole plant is damaged, in this situation it is advisable to cut it all from its base. Since although the upper part may have been frozen, the roots are surely alive and waiting to release new shoots.

We already made it clear that during the pruning of the Phormium you should cut the leaves in poor condition, another element that you should cut are the flower stalks as they dry.

3.2 When to prune

Two are the most important climatic factors that can affect the foliage of your Phormium, and these are the sun and the intense cold (especially the sun). Therefore the beginning of autumn is the time to trim all those elements that have been damaged during the summer. While the first days of spring you can prune those leaves affected by very strong frosts. Making these pruning you make sure that the plant looks beautiful throughout the year.

The time of pruning the New Zealand Flax can be used perfectly to extract new seedlings, thus helping to shrink the plant and having the opportunity to propagate it. Autumn is ideal for this type of transplant because the soil will still be warm and your plant will have a much better chance of settling.

4. Pruning New Zealand Flax or Phormium video


As in this website we like you to get out of here having everything very clear is that once we have finished the post we leave a video (we select the best one we found on YouTube). This will help you understand in a more practical way everything seen on the trimming of your New Zealand Flax. We have taken the video of the The Gardening Tutor channel.

You may also be interested in knowing about pruning:

Well with this we have finished the article, I hope that with what is seen here you have no doubts when you have to take your scissors and prune your Phormium.

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