Spiked Water Milfoil
Spiked Water Milfoil - Myriophyllum spicatum - is a submerged aquatic macrophyte. It is characterised by groups of four feathery leaves arranged around a circular stem. The stem can be slightly reddish in colour and the flowers are red. Identification should be carried out carefully as it can be confused with M. verticillatum which has light green emergent leaves, or M. alterniflorum, a species characteristic of low nutrient / slightly acidic - oligotrophic - waters.
It often forms dense mono-specific stands, or is commonly associated with Canadian Pondweed - Elodea canadensis. This plant often grows in lakes, ponds and ditches, but is not found in faster flowing water. It reproduces by seed and by vegetative growth and control measures should take this into account.
Control
Mechanical control - This plant responds well to mechanical control. The cut material must be removed from the water to avoid deoxygenation. The cut weed can be left to decompose in small heaps away from the side of the water, taking care to avoid seepage of the liquor back into the water. Our amphibious weed harvester can effectively cut and remove this weed from your water body.
Chemical control - None, due to the banning of previously used chemicals.
Biological control - The use of herbivorous Grass Carp is appropriate as a control method for this plant. Common Carp, and other bottom feeding fish, which create turbid water, can also be effective in preventing regrowth of the plant after mechanical removal.
Environmental control - Shade will control most submerged aquatic plants. This can be achieved by planting trees on the south side of water bodies or by using a floating sheet of opaque material. Care must be taken when using the latter to prevent sudden deoxygenation.