Keep Weeds Out of Your Mulch Beds.
Using PREEN or any other similar product to keep weeds out of your mulch beds is a great idea to reduce your landscaping effort each year. Most people limit this practice to early Spring, or only when they are freshening up the mulch. Although this is a great idea, you may be missing a great opportunity to keep even more of this nuisance at bay.
Spring Pre Emergent Control
Just like in lawns, Spring Pre Emergent Control is great for keeping grassy weeds out of the controlled area. Most of these Pre Emergent Controls work by creating a vapor barrier that kills seeds trying to germinate before they can get established. The problem with Spring Pre Emergent is that it doesn't work so well for Broadleaf Weeds such as Henbit and Chickweed.
Winter Time is a Great Time for Pre Emergent Control
A lot of weeds (including Henbit and Chickweed) lay dormant in the ground just waiting for that 60 to 70 degree spell. Like a sprinter at a track meet, as soon as any hot spell hits, it starts to germinate and get the process rolling. It doesn't matter if it is November, December or January. That is why these are some of the first weeds we see everywhere in early April. By putting a Pre Emergent down in December or January, you can rest assured that as soon as we are getting any warm spell at all, you are killing those weeds before they have a chance to reproduce.
Not a Perfect Solution
If you like planting seeds for flowers, you will have to consult the label to make sure the product you are using does not kill the type of flowers you are trying to grow. If it does, then I guess you have a choice to make. I strongly recommend you read and follow the directions on any and all weed control products. If you do not, you may not be happy with the outcome.