Test plots are needed for using any chemical or organic soil additive to see how well they are working. It is nice to have spots that are not treated and keep a journal of these and what and how much and when you are applying ANYTHING to a given area. Below is a link to the University that has patented the Corn Gluten meal. You also need to keep a running total of the amount of rainfall or amount of water your flower bed sprinklers are putting out on the treated areas and the dates of the rainfall.
Notice that this is basically the dried by product of all those new factories that are producing that 10% blend of ethanol that goes in our vehicle gas tanks here in the USA. As Lina mentions using this in her flower beds she is also adding a slow release Nitrogen fertilizer for her plants. (There are LOTS of micro and macro nutrients also in ANY organic mulch from tree chips to lawn grass clippings.)
Notice that originally the research found that using good old corn meal had basically the same results. SOOOO if you still have a local Grist Mill for grinding grain you can buy whole shell corn and have it finely ground to a flour and use this.
They recommend for weed control to use a MINIMUM of 20 pounds of corn meal/corn gluten per 1,000 square feet or 860 pounds per acre which is about 860 KG per hectare. By doing this you are adding 86 POUNDS of pure nitrogen to this acre for your plants to use.
Last night I bought nitrogen fertilizer for our Texas Master Gardener plant trials areas. It cost $1.67 a POUND for the nitrogen in the Cheapest brand of fertilizer. 86 Pounds of store bought bagged fertilizer X $1.67 = $143.62 per acre. Shell corn at the farm is now running $4.00 per bushel (which is supposed to weight 56 pounds per bushel) SO I could have had the corn ground up and spread on the garden plots and gotten the SAME amount of nitrogen for the soil in a time release form for HALF the price…..AND gotten a LITTLE bit of weed control.
OK take this a little further and you can get FREE grains and flour from larger feedmills and or companies that mix up or sell larger amounts of flour and or grain. If you live next door to an ethanol plant or a beer brewery you can get the grain mash pretty cheap.
Feedmills often get train car loads of wet or moldy grains that are hauled to landfills. If you use whole grain products you will get flocks of birds which is a whole other story…..
ANYWAY IF you decide to use ANY pre-emergent on your flower beds or yard map out a small section to see IF and WHAT weeds will sprout in the untreated sections….Keith Kridler Mt. Pleasant Texas