February 2017: Regrowing from root fragments
The summer rains have come and the hot sun brings forth new germinations and growth flushes in all the vegetation – the ‘good’ plants and the ‘bad’. While the soil is still moist is a good time to go weeding. When the weeds are yet small and manageable, particularly persistent perennial woody weeds like giant devil fig and groundsel, is also an opportune time.
Technique can pay off as it’s important to get all the roots. Many species regrow from root fragments left behind. Some weeds easily snap their roots or stems when you tug at them, happily sacrificing their tops and a bit of root for long term survival. Do it once, do it well. You don’t want to be coming back again and again for the same plant. For smaller weeds a hand weeding tool will loosen the soil around the deeper tap roots and tough fibrous roots ensuring they are free to exit the earth. For larger specimens a garden fork can be efficacious. Make your way around the plant inserting the tines at intervals and working the fork back and forth and side to side. When the soil structure is broken up, grasp the weed as low as you can. Take a deep breath in. Visualise the roots. As you breathe out, give the roots a little wiggle and imagine them releasing their hold as the plant slips out, roots and all.
New pest plant species can be introduced on mowing and slashing machinery. Ride-ons and tractors can easily collect plant material from the last job and carry it to the next property. Ensure your contractor practises an adequate level of hygiene and decontamination. Bulldozers, graders and other earth moving equipment can also carry clods of dirt that actually have weeds growing in them. Weeds will spring up anyway as a result of earth disturbance but can you be sure the machinery didn’t bring new weed seeds with it?
Groundsel, Baccharis halimifolia, continues to appear in the Nimbin Valley. This declared species, is spreading far and wide following a profuse flowering of a heavily infested local paddock last year. With masses of feathery floaty seeds, 500,000 to 1 million per plant, which can blow kilometres on the wind, this hardy, drought resistant shrub is likely to pop up anywhere. About half of the seeds will fall in the vicinity of the parent plant, leading it to readily establishing a thicket if further neglected and left to mature.
Get it while it’s young. Groundsel is easily recognised by its distinctive wedge shaped leaves with toothy margin. Keep an eye out and attend to new seedlings promptly to reduce your workload and limit its spread.
Giant Devil’s Fig (GDF), Solanum chrysotrichum, is another persistent woody weed common in the Nimbin Valley. Carried by birds and bats to new locations it is also hard to control if it is let establish. GDF has a characteristic kink in its tap root (pictured left) so it’s easy to cut through if trying to hack out with a mattock. The roots go deep and reshoot if bits left behind.
Hand weeding is beneficial. Exposure to soil and its microbiota and plant exudates boost our immune systems and promote good health. Physical activity also contributes to healthy living. Trials comparing the effects of exercise to taking glucosamine supplements found the exercise contributed more to relief of painful joints.
So get outside and do some gardening. But don’t forget thick gloves when handling GDF. The thorns on the stems and leaves are nasty.