Effective Treatment of Crassula Helmsii Using Hot Water

Recently I have fielded multiple enquiries for treating Crassula Helmsii, on the bed of lakes, ponds and reservoirs across the UK. The extended dry summer has seen water levels fall and the spread of this aquatic species of succulent plant. 

Commonly known as Swamp Stonecrop or New Zealand Pigmyweed, it thieves in muddy margins of ponds, is able to grow fully submerged in cool-water and does not die back in the winter months. Once established it grows and spreads vigorously and can form carpets reaching 100% coverage. 

Using chemical treatments next to and in a water course is simply not an option. The landowners are looking for a fast and effective way of controlling the problem areas. During a small trial, we used three treatment types; Electricity (Zasso Zap Weeder), Hot Air (Ripagreen Mobility Kit) and finally Hot Water (Eco Weed Killer Pro 10). 

The layered growth of Crassula Helmssi, overlapping itself, meant that electrical and hot air treatments, while still effective, achieving 50% and 60% kill rate respectively in just one treatment, struggled to penetrate the top layer of the plant. The Eco Weed Killer Pro 10 Hot Water treatment was a clear winner. The low pressure hot water, delivered at 100oC, soaked through and covered all layers of the plant, quickly wilting the weeds and leaving them in a mushy state. Seeing the effect quickly doesn’t just give you confidence in the process, but means the operator can move quickly seeing where he or she has treated. 

1 Week After Treatment:

                              Electrical                   Hot Air                        Hot Water 

The hot water raises the temperature of the plant over 80oC, this damages the cells of the weed to a point that it no longer photosynthesizes and dies. Just one week after the treatment the plant has browned off.  

4 weeks after treatment, the lasting effects can clearly be seen. 

Tackling new problems can often be a challenge. Finding the correct treatment, then offering and delivering an effective solution to a customer is always a satisfying feeling. Now treatment can commence in any weather conditions, before the water levels return to normal.