Much has been written about summer being the hardest time of the year for the turf here at Granite Bay Golf Club. In addition to the heat and long days of summer being hard on the cool season turf that encompasses most of the course, these summer conditions facilitate every type of pest as well. Disease, insects and weeds all prosper when the weather gets hot. Therefore our task to maintain healthy cool season turf in the summer goes beyond managing irrigation and into prevention of disease, insects and annual weeds but reacting and pushing back on perennial weeds.
Annual weeds such as crabgrass are much easier to prevent so are not as much of a problem as perennial weeds. Annual weeds emerge from the seed they produced the previous year(s). Pre emergent products that prevent the weed from germinating, establishing and producing seed interrupts the cycle and keeps that pest problem in check.
Perennial weeds return every year from both seed and root and stem system's that have overwintered. If they are not prevented or eradicated their spread will just continue. Preventing and eradicating is easier said then done with some of the weeds we that have taken a foothold here at Granite Bay. A picture is worth a thousand words so below are some illustrations of the various weed issues and control strategies for those who are interested.
Dallas Grass (paspalum dilatatum)
|Dallas grass in a bunker finger on #12. |
We will just dig these out and hope we get all of the roots.
Knotgrass (paspalum distichum L)
|Knot Grass in the process of selective control.|
|Example of slight discoloration of the desirable grass while using selective products to control knotgrass in #9 FW|
|A few years back we attempted the non-selective approach of controlling Knot Grass in #9FW. After the knotgrass was dead along with all surrounding desirable grass we seeded and topdressed.|
|The following year we still had Knot Grass reemerging in the areas we had seeded. Needless to say the non selective approach of eradication was scrapped.|
Nutsedge (cyperus rotundus L)
|Yellow Nutsedge patch in the approach of #16|
Weed control and prevention will always be something we will deal with in one way or another here at Granite Bay and most of the heavy lifting will occur in the summer months when the perennial weeds are actively growing. Until a effective selective product is available for control and eradication of Dallas Grass and Knot Grass we will have to rely on old school chemistry for control which currently does not completely eradicate the weeds but keeps them pushed back.