Some very important lawn care treatments will take place over the next month. We will put out the first pre-emergent treatment the first week of March. Right now soil temps are in the low 50's, crabgrass can germinate when soil temps get around 60 degrees. This year we will be using Barricade pre-emergent for crabgrass control, its known as the strongest (and most expensive) pre-emergent product. I will also be spraying lawns to get rid of any broadleaf weeds (like chickweed and henbit- see pics below) out there. You will get a lawn sign notifying you that this was done, for liquid applications you want to keep kids and pets off the lawn at least until its dry.
There are a lot of factors (mostly weather) that can reduce or increase the effectiveness of any pre-emergent or weed control we use. For those of you that did have weed breakthroughs last year, I’ll be making adjustments to application rates, timing, and products to try to increase the effectiveness of the treatments.
The Spring green-up of the grass also signals the time for weeds to break through. Broadleaf weeds like chickweed and henbit are easy enough to control (we hit em hard with herbicide) but sometimes we see the nastier ones like poa annua that are not so easy to control. Here is a description of some of the common weeds we are seeing now.
(aka annual bluegrass) is one of the most difficult weeds to control. On the west coast you will find Poa on beautiful golf course greens. Here in the Carolinas, it is a nasty invasive weed in our lawns.
Poa germinates in the Fall, around the same time we are renovating lawns, and starts appearing in early Spring. It produces massive seed heads in April/May and then completely dies out when it warms up in May/June. Poa seeds can lay dormant in the soil for 10-15 years and then suddenly pop up as soon as an opportunity arises (thin areas of turf or not yet established new grass). I’ve seen it every year especially in the lawns that were heavily renovated for Bermuda. In these cases we worked the soil over so much with our aerators that any dormant seeds were brought to the surface and germinated the same time our new grass was coming in.
Once it starts growing it produces dense seed heads and is unsightly in the yard. There are some options to take to control Poa. If you want to get rid of your Poa Annua RIGHT NOW, we need to remove the weed areas and lay new sod. Unfortunately this is also the most costly option. The second option is to wait it out until the Poa dies off on its own in May/June. Then we can apply an extra pre-emergent treatment in August to prevent the Poa from germinating in the Fall. Also, a newer herbicide called ProGrass can be applied in the fall but perfect timimg is crucial for this to work. I can see improvement on the lawns that got this treatment last year; however, this does not give 100% control right away. It takes several years of this process, as well as promoting healthy turf, to eliminate poa annua.