Are Ornamental Gingers Invasive?


Unfortunately, some ornamental ginger varieties have proven to be invasive. Thankfully this categorization does not apply to all ornamental gingers but just a select few. Some of the reasons they are invasive are discussed below.

The problem with any collectible plant within the gardening fraternity is thatit is most likely to be removed from its natural environment, where natural restraints are working to contain and restrict the spread of the plant.

This could be geographical, climatic, or biological. The plant may have a rigid boundary from a mountain range or an ocean in the geographical setting. Madagascar is an excellent example of this.

Climatic restraints are where the plant cannot grow in a colder or warmer environment other than where it grows naturally.

Biological restraints may be where a plant is a food source for a specific type or group of animal or insect, and this natural form of control can contain the plant’s range. Soil types can also play a part in preventing plant spread.

Gardeners have bypassed all of these barriers and have introduced varieties from across the globe to their gardens. This has broken the restraints that may have contained that particular plant.

This is not to say that gardeners are bad people, as it is most often only after the fact that the problems of invasive ornamental plants are discovered. By this time, it is all too often too late.

What ornamental gingers are invasive?

There are several varieties of gingers that qualify, and some of them are listed below.

  • Hedychium gardnerianum , Kahili Ginger
  • Alpinia purpurata , Red Ginger
  • Hedychium flavescens , Yellow Ginger Lily
  • Hedychium coronarium , Butterfly Ginger

It seems that the hedychium genus is problematic and has been declared an invasive species in several countries including South Africa, Australia, New Zealand, and Hawaii.

How are invasive gingers controlled?

Several methods have been employed, ranging from the physical removal of the plant to chemical control agents being applied.

Physical removal is difficult to apply to the gingers because of the strong likelihood of not getting all of the rhizomes from the site.

Because these gingers are so aggressive, it is often the case that chemical controls end up being employed. However, they come with their own set of issues as sometimes the chemicals have great potential to harm the local environment.

As the invasive gingers are being addressed, and if this process is applied poorly, the potential cure can be worse than the disease. In the case of the kahili ginger, it is a very invasive species and has been named in the top 100 most invasive species globally.

How do invasive ornamental gingers spread?

Once established, these gingers can spread by rhizomes andby seed that birds spread. In the case of the Kahili Ginger, the plant can live for 70 years and will flower for most of this time.

It prefers wet soils, so it can be found along the edges of waterways where the occasional flood events can spread seed and rhizome further. It will form dense stands and can become the dominant species in an ecosystem.

A problem is also made worse by un-witting gardeners dumping the plant in locations where there are no control measures, which allows the plant to establish clumps away from the original source.

Knowing how your gingers reproduce is essential because you can accidentally spread it by trimming the plant.

Ornamental gingers can be spectacular plants when they are kept in check, and sometimes this means cutting them back. Cutting them back?

Yes, ornamental gingers require pruning to maintain the effect these plants can give to a landscape.

According to Merriam Webster, “ornamental” means 1: a decorative object and 2: a plant cultivated for its beauty rather than for use.

Many ginger varieties fall into this bucket and have been planted in many landscapes worldwide. Botanical gardens in the world’s cities hold many of the most spectacular types and are well worth exploring and enjoying.

Did you know that some ornamental gingers possess another trait? We have an extensive list of ornamental gingers that are also edible, and it is titled 21 edible ornamental gingers. We recommend it to anyone looking at a new planting.

Because of the enjoyment value of these plants, it is best practice to keep them trimmed to keep them at their best at all times.

The growth habits of these ornamental gingers is such that they have stems that die off, and the flowers that are on stalks do only last for so long.

In the natural environments where these gingers are found, the plant parts that are spent and fall go towards the mulching of the ground and end up being recycled into plant available nutrients that maintain the plant’s growth.

This process of natural mulching doesn’t fit in some landscape gardens. People like to keep the scene as manicured as possible, so replacement mulch will be required to be placed around these moisture-loving plants.

When should ornamental ginger plants be trimmed?

This will depend on your circumstances, but generally, gingers should be pruned after flowering to maintain lush fresh growth and a clean look. If the variety is a known invasive plant, have a plan to deal with the seeds and cuttings. Either burn the seeds/cuttings or hot compost them, ensuring that the internal temperature of the compost gets above 65c degrees.

Because some of these gingers will flower all year long if grown in warmer climates, the task of cutting them back is a non-stop process. How often you need to trim will depend on the variety and the plants’ location.

How do you cut back an ornamental ginger?

To cut back an ornamental ginger plant, it is good practice to take a limb saw and remove the stem or flower spike at ground level if possible. This won’t harm the plant and will keep the visual integrity of the ginger intact.

Having stems that are cut halfway up the stalk is easier but can be a little untidy in some situations. The flower spikes can be removed before they die back and can be used as cut flowers if desired.

Gingers that are well watered and kept trimmed can be a great addition to a landscaped yard, but it would be wise to research what variety to plant before you go and get one.

Are ornamental gingers taller than edible gingers?

Generally speaking, ornamental gingers (both invasive and non-invasive) are taller and also grow all year in warmer climates. These ginger varieties can be over 15 feet tall (5mtrs) and can be extremely attractive.

The range of choices of these gingers is extensive, and every one of them has its differences, but the clumping habits are generally the same. Depending on the variety, they can grow from rhizomes or seeds and be invasive or easily controlled.

What is the tallest ornamental ginger plant?

The torch ginger is possibly the tallest at 15 feet; however other varieties could be taller if grown in optimum locations.

Several gingers are close to this height, with more at around the ten-foot mark.

Think about where you plant these as the leaf fronds can block paths and walkways if not trimmed. If they are looking beat up, it could be because they are getting too much sun. We discuss the sun requirements in “can ornamental gingers grow in full sun?

There are incredibly spectacular varieties like the torch ginger. This ornamental ginger responds well to pruning and will force the plant to grow more flowers in time.

The flowers can last up to a week indoors, and then the spent flowers can be returned to the garden as mulch to be recycled.

Will pruning ornamental ginger spread seeds?

In some cases, cutting off stems that have viable seeds attached can and already have spread the seeds of some ornamental gingers.

Last words on invasive ornamental gingers.

  • Research ornamental ginger varieties for problematic behavior before buying and planting.
  • Be vigilant if you do have an invasive ornamental ginger variety in your yard.
  • Understand the potential damage that can be caused to your local ecosystem by these gingers.

Article by Tim Blanch for He is a qualified Permaculture designer.