In spring Japanese Knotweed appears as soft red/purple shoots, resembling asparagus spears. As it grows the spear tips which are actually tightly curled leaves start to unfurl and it looks like a small shoot with red tipped olive green leaves that point upwards.
How can I identify Japanese Knotweed in spring?
Japanese knotweed looks very different through the seasons. In early spring (March-April), the small shoots can be hidden beneath the undergrowth or in grass as the growing season gets going. As the picture below shows they don’t always have the asparagus appearance, and can simply look like a small red, leafless stem. But as these shoots get taller they are more visible and the leaves begin to unfurl.
Japanese knotweed spring growth can emerge from last season’s crown as shown below. The tips can be paler in colour but we can see the clearly defined leaves at this stage still tightly packed around the shoot tip. These will uncurl as the shoots start to grow.
How can I spot Japanese Knotweed in Spring?
In late spring look for shoots with lime green foliage that is now growing diagonally from the shoot instead of pointing upwards. Knotweed plants can grow up to 10cm per day in spring so they will change rapidly. The shoots will grow to form tall stems with green leaves (which may be lighter at this stage) that grow in a zig-zag pattern, though in early spring this may not be as clearly defined and may look like the image below with just a few leaves at the top of the stem. We can see the speckling of the stems in spring which is a key characteristic of knotweed spring growth.
Why it is important to get knotweed identified in spring
Knotweed can cause damage to structures and will put construction projects on hold, so it is vital to get it identified as early as possible – spring being the best season to do this. Many houseowners consider spring to be the optimum time to put their property on the market. To ensure there are no issues with knotweed to factor in to the sale we recommend having a pre-sale survey.
Free identification
If you really want to find out whether a plant you’ve spotted is knotweed, we offer a free identification service, simply upload your photos and one of our experts will analyse them and send you the results.