Some of the toughest plants in a Perth garden are also the ones most likely to cause trouble outside it. A plant that thrives on little water and no care can do the same in nearby bushland. Once it gets there, it competes with native plants. Gardeners can do a lot to stop that happening.
These plants are often called garden escapes or garden escapees. They start life as ornamentals in a front yard or along a fence. Then seeds, cuttings or bulbs find their way over the back fence. The fix starts with what you plant and how you get rid of garden waste.
How garden plants reach bushland
The WA Department of Primary Industries and Regional Development explains how garden plants invade bushland in several ways. Wind carries seeds, and waterways move seeds and plant fragments. Birds spread seeds after eating berries. With so many ways to travel, the department says the only way to stop some plants becoming environmental weeds is not to grow them in the first place.
People move weeds too. Seeds can travel on clothing, shoes, pets and car tyres. Green waste taken to the tip in an open trailer can drop seeds and cuttings along the roadside. Each of these is easy to overlook on a busy weekend.
Why dumped garden waste causes trouble
Dumping garden waste in bushland is a direct way to bring in weeds. The waste can hold seeds or plant parts that regrow. As it breaks down, it also enriches the soil in ways that favour weeds over native plants. So a pile of clippings can do harm long after the leaves have rotted away.
Succulents are a good example. The City of Joondalup notes that they can grow from discarded leaves or stems. Small fragments of turf grasses such as kikuyu, buffalo and couch can also take root if dumped with garden refuse. What looks like harmless rubbish can become a new patch of weeds.
Garden plants that can go wild
Many familiar plants appear on local weed lists. The City of Joondalup garden escapee weed guide names a long list of them. It is worth checking your own garden against it, or against a list from your local council. Here are some of the groups and examples it covers.
- Bulbs such as freesia and yellow soldiers, which regrow from underground storage organs
- Ornamental grasses such as fountain grass, tambookie grass and pampas grass, which produce large amounts of windblown seed
- Succulents such as agave and pig face
- Clumping plants such as gazania, agapanthus, veldt daisy and dietes
- Shrubs and trees such as olive and Brazilian pepper, whose seeds are spread by birds
- Aquatic plants such as parrot’s feather and water hyacinth
Some of these are marked in the guide as declared plants, including arum lily, parrot’s feather and water hyacinth. Others are simply popular choices that spread well. The guide also lists some Eastern States wattles, such as Cootamundra wattle, as garden escapees. A plant being Australian does not always mean it belongs in your local bush.
Choosing plants that stay put
The simplest step is not to plant species that can become environmental weeds. That advice comes straight from the department. The Joondalup guide suggests choosing local native species where possible. Specialist native nurseries can help you find plants suited to your soil and climate.
A garden built on local plants can look just as good as one full of exotics. These tips for landscape design in dry areas cover layout ideas that suit native plantings. If you are rethinking a whole yard, landscaping ideas for gardens without lawns may also help. Fewer runner grasses means fewer fragments to escape.
Lawn choice matters as well. The Joondalup guide lists kikuyu, buffalo and couch among its garden escapees, as they spread by seed and runners. Some people weigh up synthetic turf for this and other reasons, and there are several points to consider before adding artificial grass. Each option has its pros and cons, so think about how you use the space.
Managing weeds already in your garden
The department suggests removing existing invasive plants from the garden. The Joondalup guide adds that you can manage them before they escape, for example by cutting off flowers to stop seed spread. Bulbs and corms are slow to remove by hand because they regrow from underground. Expect to dig carefully and come back to the same spot.
After clearing a patch, do not leave the soil bare. The guide recommends dense mulch and replanting cleared areas with suitable species to stop weeds coming back. Bare ground is an open invitation for new seedlings. Reading about how Perth’s climate shapes landscape design can help with plant choice for those gaps.
Getting rid of garden waste the right way
Careful disposal is the other half of the job. The department recommends covered loads when taking green waste away, so seeds and cuttings do not escape on the road. Never dump clippings or prunings in bushland, reserves or on verges. Use your council’s green waste collection or an approved green waste facility.
Check your council’s advice before putting weeds in a bin. The City of Joondalup, for example, points residents to its green waste collections and its green waste recycling facility. Rules vary from council to council, so look up your own. Grass clippings can often be mulched or composted at home, as the Joondalup guide suggests.
Getting involved beyond the fence
If you want to do more, local bushland Friends groups help with restoration work. The Joondalup guide encourages residents to join one and learn about native plants. It is a practical way to see which weeds cause the most trouble in your area. You will also pick up plant ideas for your own garden.
Frequently asked questions
What is a garden escape?
A garden escape is a plant grown in a garden that spreads into bushland or other natural areas. It can travel by seed, cuttings, bulbs or runners. Once established, it competes with native plants. Many are common ornamentals.
Can I put weeds in my green waste bin?
It depends on your council. Councils set their own rules for green waste and weeds. Check your council’s website before you fill the bin. If in doubt, use a council green waste collection or drop off.
Are Australian native plants always safe to grow?
Not always. The Joondalup guide lists several Eastern States wattles as garden escapees. Choosing plants local to your area is the safer option. A specialist native nursery can help you pick them.
How do I take green waste to the tip safely?
Cover your load. The department notes that open trailers can drop seeds and cuttings along the roadside. A tarp or a covered trailer keeps the waste contained until it reaches the facility.
