Like all weed problems, aquatic weed problems often take years to develop.
When the developing problem is noticed, however, there is often a tendency to wait and either hope the problem goes away or get a cheap herbicide to kill the weeds.
There may be some situations where one of these ideas may work. In reality, the weed problem will not go away, and there are not many cheap herbicides that can be used for aquatic weed control.
With the exception of the various species of algae, aquatic plants reproduce by seed. The plants noticed in the pond last year made seed, which will begin to germinate soon if they have not already done so.
Also, some plants survive the winter and these plants along with newly emerging seedlings ensure that weed problems noticed last summer will probably be worse this year.
The moderate weather we've been having makes it an excellent time to stock grass carp. Grass carp may be stocked in suitable ponds any time of the year.
The winter months or early spring are particularly desirable because mortality associated with handling stress is less likely when the water temperature is cooler. Therefore, fish stocked in the late winter or early spring are more likely to survive.
Grass carp feeding is negligible at water temperatures of less than 50 degrees.
However, as water temperatures begin to warm in the early spring, feeding activity increases and reaches its peak at water temperatures between 70 and 80 degrees.
If one considers that aquatic weeds begin to grow and seeds begin to germinate as water temperatures warm in the early spring, it becomes clear that having grass carp in the pond before weeds initiate growth is highly advantageous. The fish are there ready to feed on newly developing aquatic weeds.
Often, it takes a couple of years for grass carp to control high populations of aquatic weeds.
As mentioned, grass carp can be stocked any time of the year, but stocking now may assist the fish in controlling the weed problem more quickly when compared to midsummer stockings when weeds are growing so fast.