Question
I have heard for sometime about the use of corn
gluetin as an effective and economical way of controlling grabgrass. What was not readily apparent was where to buy the material and when to apply it. I have heard two points of view about the application time- one suggesting the spring and the other the fall. Do you have an opinion or suggest regarding the product or alternatives.

Thanks,
Steve Davis

Answer
Good afternoon Steve:

The web site below might give you some idea of what some of the users of corn gluten are experiencing. Some are saying it is expensive and hard to come by.

http://www.lawnsite.com/archive/index.php/t-62463.html

I believe if corn gluten was the answer for crabgrass control the state universities that research such things would be telling their agricultural people and their Master Gardeners all of its virtues and they are not.

Corn gluten, like a fertilizer, increases the density of the grass. By increasing grass density it creates a shade canopy that weeds, including crabgrass, do not find conducive for their growth. If you follow good cultural practices by mowing 2 ?to 3 inches high and mowing frequently removing no more than one third of the grass blade at each cutting you will also create a shade canopy.

Some general information about crabgrass is as follows:

Crabgrass is the most common annual weed in most lawns. Both the smooth and hairy types of crabgrass are classified as summer annual weeds. Crabgrass is usually lighter green in color, has wider leaf blades and a more spreading growth habit than  cool season turfgrasses. To ensure crabgrass and other annual grass weeds do not establish in home lawns, both preventive and control programs must be implemented. The invasion of crabgrass and other annual grass weeds can be prevented to a large degree by maintaining a dense, healthy stand of grass. A high quality lawn will  shade the soil surface and discourage the germination and establishment of seedling annual grass weeds. Most annual grass weed seeds germinate in the top 1/2 inch of the soil.
The crabgrass seeds in the soil begin to germinate in the spring once the soil temperatures warm to nighttime minimum temperatures of 52 to 54 degrees F for at least 5 consecutive nights under conditions of moist soils.
the best way to stop annual grass weeds from establishing in their lawns is through the use of preemergent herbicides.  These herbicides control annual grass weeds by inhibiting cell division in the young root system. Lawns with thin stands of grass may require yearly applications of a preemergent herbicide to prevent the invasion of crabgrass.
If crabgrass weed control is desired in new seedings or where young, desirable seedling grasses are developing, Siduron is the only herbicide that will provide control of the annual grass weeds but not injure desirable seedling turfgrasses. Siduron may be applied at the time of seeding.
Preemergent herbicides are generally only effective if applied before the annual grass weeds emerge. Therefore, early spring applications are essential if satisfactory weed control is to be achieved.

In short Steve I would stick to the tried and true method of crabgrass control.

Good Luck!
Floyd McMahon