Scurvy weed (Commelina cyanea)
Scurvy Weed is also known as Forget-Me-Not and Native Wandering Jew. It is not in the same family as Wandering Jew.
After you read this, you will be able to:
- Identify Native Wanderng Jew or Forget-Me-Not.
- Know the habitat of Scurvy Weed or Forget-Me-Not.
- Know the best options to control Forget-Me-Not.
While Scurvy Weed (Commelina cyanea) is a native Australian plant, it is considered a weed in certain situations. At first glance it looks like the introduced weed, Trad (Trandescantia fluminensis).
However, the lance-shaped (lanceolate) leaves of Scurvy Weed are narrower and it has bright blue (rather than white) flowers. Scurvy Weed tends to grow rapidly in warm and/or wet weather and die back in the cooler, dryer months.
Why is Scurvy Weed a Problem?
- It grows rapidly and forms a dense ground cover that smothers other plants.
- Commelina cyanea thrives in damp, shady areas, and it is common in gardens and along watercourses.
- Scurvy Weed is a long-lived, invasive, branched, creeping weed of gardens.
- This weed is able to cope with saturated soils and temporary flooding.
How to Identify Scurvy Weed.
Scurvy Weed, Native Wandering Jew or Forget-Me-Not spreads vegetatively via its creeping stems, and by seeds. Seeds and stem pieces spread by water, and also in contaminated soil.
Category: Dicot.
Photosynthetic Pathway:Scurvy Weed is a C3 Weed. This means that it has a high efficiency of CO2 uptake in shade.
Flower: The flowers of Forget-Me-Not, are in small clusters, and have three bright blue (rarely white) petals. These flowers only open in the morning.
Height: Scurvy Weed has a prostrate growth habit.
Leaf length: Its leaves are 4 to 6 cm long, elongate and have pointed tips.
Leaf width: Scurvy Weed leaves are 2 to 24 mm wide, and have hairs on their leaf margins.
Reproduction: Forget-Me-Not spreads via its creeping stems, and by its seeds.
Comments: Scurvy Weed leaves are alternate along the length of their stems. The stems have a high moisture content, and once it is well rooted it survives for long periods without moisture.
Habitat: Native Wandering Jew is usually found in high humidity areas under the shade of trees.
Scurvy Weed (Commelina cyanea) is a good soil indicator of high nutrient soils.
For more information check out our weed ID Chart.
How to Control Scurvy Weed in your Lawn.
You can control Forget-Me-Not by cultural and chemical means.
Cultural Control of Scurvy Weed.
- Native Wandering Jew is a difficult weed to control by hand as small pieces of the plant will re-grow. You need to remove all vegetative material and dispose of it off site.
- Encourage a thick, dense grass cover. This enables in turf grass being able to outcompete this weed.
Chemical Control of Scurvy Weed.
Many common herbicides have relatively low activity on Commelina. These include 2,4-D, propanil, butachlor, trifluralin and pendimethalin.
Pre-emergent Herbicides for Scurvy Weed.
- Pendimethalin.
Post Emergent Herbicides.
Treatment with 2,4-D or MCPA gives a reasonable kill of very young Scurvy Weed, but the plants develop a resistance as they mature.
- Bentazone,
- 2,4-D.
- 2,4-D at 2L/Ha + Glyphosate at 2L/Ha + Ally at 5g/Ha gives a 75% control.
- Picloram
- In Fiji, you can use metsulfuron-methyl.
Non Selective Control of Scurvy Weed.
- Glufosinate-ammonium provides control for 4 to 6 weeks, but it re-grows and recovers due to the limited movement of glufosinate.
- Glyphosate. This does not work very well to control Scurvy Weed.
The following are non-selective but also have a long term residual and stop re-growth of Forget-Me-Not.
- Renegade. Renegade stops the germination for up to 12 months, and reduces the need for multiple herbicide applications.
- Numchuk Quad. This gives effective post and pre-emergent control of Scurvy Weed for up to 12 months.
- Cortex Duo. Cortex Duo gives a rapid knockdown of Native Wandering Jew, and residual control for up to 3 months. It is also safe to use around trees.
Table of Non Selective Control Options for Scurvy Weed.
Product | Active | Chemical Group | Rate/Ha |
Glufosinate 200 | Glufosinate-ammonium | 10 | 1-6L |
Rapid Fire 800 | Glyphosate | 9 | 0.9-1.35 Kg |
Numchuk Quad | Terbuthylazine + Glyphosate + Amitrole Oxyfluorfen | 5 + 9 + 34 + 14 | 20-25L |
Cortex Duo | Nonanoic Acid + Oxyfluorfen | 14 | 7L/1000L |
Renegade | Bromacil | 5 | 3.5-6.5Kg |
