Oriental False Hawksbeard (Youngia japonica).
Oriental False Hawksbeard (Youngia japonica) is an highly invasive, annual and bi-annual weed of waste ground, cultivated fields and roadsides. In Australia it is generally found on the east coast, from Sydney north.
False Hawksbeard is an herbaceous flowering plant with a solitary, erect growth habit. It is often mistaken for Dandelion in the vegetative phase. Once it flowers it also looks like weeds such as Catsear.
As Youngia japonica is an annual, it needs bare soil to establish every year, unlike perennial weeds like Dandelion which only need to establish once.
After you finish reading this, you will be able to:
- Identify Oriental False Hawksbeard.
- Know the habitat of Oriental False Hawksbeard..
- Know the best cultural and chemical options to control False Hawksbeard or Youngia japonica.
Mature plants have a basal rosette of leaves and a single main stem, that branches near the top to produce a small number of flower stalks.
The leaves are fairly large and broad, with deeply lobed margins in the basal half. They are covered with short, bristly hairs, and have a reddish thin reddish stem covered with short hairs.
How to Identify Oriental False Hawksbeard.
Category: Herb.
Flower: The bright yellow flowers occur on short stalks. The flowers of False Hawksbeard are about 12mm in diameter. Each flower has up to 20 circularly arranged, golden-yellow ray petals.
Height: Hawksbeard is an erect annual herb to 60 cm high, and has a hairy base.
Leaf length: The Leaves are 1.5 to 2 cm long, attached at the base and on an aerial stem. They are oblong or obovate, and the terminal lobes are larger than the basal ones, with large terminal segment, The leaf margins are finely toothed, with a smooth, glossy surface.
Leaf width: The leaves are 1 to 5 cm wide.
Dispersal: Hawksbeard reproduces solely by seeds that look like dandelion seeds. Seeds are dispersed by wind, water & by people
Comments: The lower leaves are simple, spatulate, and hairy, with a lobed margin. The hairless, linear leaves found on the upper portion of the stem are the same as those along the flower stalk. The leaves and stem will expel a milky sap if damaged. Seedlings of Hawksbeard grow in a rosette (circular arrangement), emerging from a central point at the soil lineThe lobes of Dandelion leaves tend to point down towards the base of the leaf, whereas hawksbeard lobes point directly outwards. Once the weeds flower, they become easier to tell apart. Hawksbeard has branched, leafy flower stems, unlike Dandelion, and Catsear.
The image below is courtesy of Massey University in NZ.
Habitat: It will grow in almost any soil types, in semi-shade or no shade, and requires moist soil.
Oriental False Hawksbeard is a good soil indicator weed of moist soils. For more information check out our weed ID Chart.
How to control Oriental False Hawksbeard.
You can control Oriental False Hawksbeard by cultural and chemical means.
Cultural control of Hawksbeard.
Hand weeding is easy to do but you must remove both above-soil and underground plant parts.
If you try and remove False Hawksbeard by mowing it is ineffective, as this weed regrows if any root remains. Ideally remove this before it matures, and becomes well rooted in the ground. The key to its control is to remove it before it seeds.
If you maintain a thick, dense grass canopy it promotes healthy turf, and gives turf grass a good chance of to outcompete Oriental False Hawksbeard.
Chemical control of Hawksbeard.
Pre-emergent Control.
These are not registered in Australia for this weed currently.
- If you apply Oxadiazon (Echelon or Echelon Duo) every 3 months, it gives good prevention of Hawksbeard.
- The NZ label for the pre-emergent herbicide Esplanade, has a registration for Hawksbeard but this is not registered in Australia for this.
- BASF Freehand.
- Onset 10GR.
Selective Post Emergent Control.
Currently there are several options available for selective post-emergent control of False Hawkweed in Australia. These are not all currently registered for this weed.
- ProForce Warhead Trio.
- Stature Herbicide.
- Dicamba. Do not use Dicamba on Buffalo grass
- Duke Herbicide.
- ProForce Contra M. Do not use Contra M on Buffalo grass.
Non-Selective Control of Hawksbeard.
There are resistance issues with paraquat and diquat to Hawksbeard.
You can use Glyphosate as a non-selective control, which means if you want to treat this weed in your lawn you will have to spot treat the weed.
The following are non-selective but also have a long term residual and stop weed re-growth.
- Renegade. This stops weeds for up to 12 months, and reduces the need for multiple herbicide applications.
- Numchuk Quad. Gives effective post and pre emergence weed control for up to 12 months.
- Cortex Duo. Gives a rapid knockdown of False Hawksbeard (Youngia japonica), and residual control for up to 3 months. Cortex Duo is safe to use around trees.
