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Home
 Newsletter ArchiveMay 1997 |
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| Balloon vine (Cardiospermum grandiflorum) |
Balloon vine (Cardiospermum grandiflorum) is another unwelcome exotic plant visitor to our shores. It occurs naturally in tropical Africa, Asia and America and was probably introduced to Australia as an ornamental garden creeper. Balloon vine is easily recognisable with its compound leaf, which has toothed light green, thin textured, hairy leaflets. Flower stalks bearing small white flowers arise from the leaf axils of the plant (the joint between the stem and the attached leaf stalk) from Summer through to Winter. The most notable feature of the plant is the fruit, which is formed after flowering. This consists of a roughly spherical, balloon like (this explains the common name of this plant) thin walled capsule, which contains several large black seeds.
Balloon vine can be seen growing in most of the riverine rainforest remnants around Brisbane.
The inflated balloon-like fruits of the plant float readily and aid its dispersal along waterways especially during flood times. This vine is most commonly encountered on the margins of rainforest. It favours high light situations where it can climb, with the aid of climbing tendrils into the canopy of trees growing on the forest edge. The thick curtain of vine stems, which are formed by vigorous Balloon vine infestations, smothers existing native vegetation. The vines eventually kill native rainforest plants by a combination of canopy collapse and reduced photosynthesis.
The combined weights of many hundreds of vine stems also acts to collapse the existing edges of infested rainforest stands. All local rainforest remnants are small and any reduction of their edges exposes the vital core areas of the forest to greater risk of weed invasion, entry of feral animals, fire, erosion and a number of other threats.
Control Methods
Both chemical and manual weeding methods can control Balloon Vine.
Large individual vine stems can be cut close to the ground and the basal stem cut painted with 100% Glyphosate (undiluted
Roundup). Curtain infestations where hundreds of vine stems are growing together can be cut at waist height. The top growth will die off and eventually fall out of the canopy. There is no need to try to pull all of the aerial parts of the vines from the canopy as this can damage the native plants they are climbing on. The cut off basal stems of the vine will re-shoot leaves which can then be foliar sprayed with Glyphosate (Roundup) at approximately 1:100 dilution. Some regenerators use a stronger spray mixture-up to 1:50.
Adjust your mix according to the results you obtain. Any vine seedlings can be successfully hand pulled or can be foliar sprayed if required. Balloon vine is not difficult to control and concentrated efforts can clear large infestations in a fairly short time. As with any weed species there is a need for follow-up maintenance and spot weeding to control newly germinated plants. This should be part of your ongoing maintenance plan.
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