Japanese Stiltgrass

Japanese Stiltgrass PlantsJapanese Stiltgrass Plants

What we are looking at there is Japanese Stiltgrass. 

Some NJ & PA locals call it stiltweed or cucumber weed (no idea why). 

First reported in 1919 in Tennessee, this annual invasive weed has been really getting established in Wayne and Pike counties in the last few years. 


Many of the eastern US states consider it invasive, as indicated by the color-filled states on this detail of a 2023 map from the University of Georgia Center for Invasive Species and Ecosystem Health.

The states showing white are either not having a problem with it or are not reporting it.

2023 Japanese Stiltgrass Map

We are seeing it take hold at may of our properties.  This is happening to properties that, just 2 years ago, had no Japanese Stiltgrass anywhere in sight.

It prefers shade and moist soils and likes to grow on roadsides and in ditches.  Rainy spring weather contributes to a flush of early summer growth.

It seems to really take off when the nights are cooler, just as other weeds are slowing down.   In our experience it can grow 10 inches or more in a week at the end of summer & beginning of fall. 

Not sure if what you have is Japanese Stiltgrass or some other weed?

Japanese Stiltgrass Leaf CloseupJapanese Stiltgrass Leaf Closeup

Look for the distinctive reflective hairs along the center of each pale green leaf to be sure.

One good thing about this weed as opposed to many others, is that is rare that we find it growing in an established lawn or ground cover filled bed.

We are seeing it pop up along the edges of lawn, planting beds, driveways and roads where there is bare soil for the seeds to take hold in.

Control & Removal

Stiltgrass is a true annual and a prolific producer of seeds because is can self-pollinate.  No part of the plant survives over winter.  That means that if you can prevent the seeds from sprouting, it can be stopped.

If some seed does germinate, the key to removal is to pull it while it is green. Pulling can remove the shallow rooted green plants in their entirety.

Once the stems start to redden, it's too late to effectively hand weed.  Hand pulling will separate the plants at the nodes and you come away with a very small piece rather that the whole stem and roots.  As the plant is separating you are probably dropping seeds everywhere.

If you do end up with a pile of hand weeded material, don't put it in your compost pile or toss it in the woods. The seeds will just produce new plants the following spring.

The best way to ensure that this material won't cause a fresh infestation is to burn it.  Unlike some seeds, Japanese Stiltgrass seeds do not survive a good toasting.

Controlling Japanese Stiltgrass on our clients properties

Apple Creek will use organic methods before turning to chemical measures.

We have had success at properties at which we applied  a pre-emergent product (usually corn gluten based) in the spring and followed up with hand weeding in the summer & fall.

In most cases, we do not apply herbicide, organic or otherwise, in planting beds and along lawn edges because it can also kill your grass, ground cover and damage the larger plants where the weed is growing from the base. 

The pre-emergent application prevents weed seeds from germinating and does not affect the established bedding plants as spraying herbicide does.

Give us a call if you would like a quote to control this weed on your property.