I live in Colorado and I think my lawn is mostly bluegrass. I had a lot of weeds last year, and I want to try to reduce them this year. It looks like my 5 day soil temps are at 45f degrees. Should I go ahead and apply a pre-emergent? Should I power rake and aerate before the pre-emergent? It hasn't been power raked or aerated for a couple years.
Any advice is greatly appreciated.
by Diamondhands009
2 Comments
Dethatching is done way too often and unnecessarily IMO. I would only aerate unless you have excessive thatch buildup and your yard is mature.
You live in Colorado and didn’t come to us first with your lawn care questions?! Devastated : P
>[**Lawn care in Colorado**](https://extension.colostate.edu/topic-areas/yard-garden/lawn-care-7-202/)
*Core Cultivation or Aerating* (info is ~2/3 of the way down the page I linked to above)
>[Core cultivation] is more beneficial than power raking. It helps improve the root zone by relieving soil compaction while controlling thatch accumulation. Soil compaction, in fact, is one factor that contributes to thatch buildup.
>Aeration removes plugs of thatch and soil 2 to 3 inches long (the longer, the better) and deposits them on the lawn. A single aeration using a machine with 1/2-inch diameter tines removes about 10 percent of the thatch if enough passes are made to achieve an average 2-inch spacing between holes.
>Disposing of the cores is a matter of personal choice. From a cultural perspective, there may be an advantage to allowing the cores to disintegrate and filter back down into the lawn. Mingling soil and thatch may hasten the natural decomposition of the thatch. The little fluffs of thatch and turf that remain can be collected and composted.
>Depending on soil type, core disintegration may take a few days to several weeks. Irrigation helps wash the soil from the cores. Dragging a piece of cyclone fence or an old metal door mat can speed the process. Running over the cores with a rotary mower can be effective but can dull the blade. Many commercial companies that perform core cultivation break up the cores with a power rake. If the cores are removed from the lawn, compost them before using them as a mulch or soil amendment.
**Additional Colorado lawn resources:**
* [Control of annual grassy weeds in lawns](https://extension.colostate.edu/topic-areas/yard-garden/control-of-annual-grassy-weeds-in-lawns-3-101/)
* For extreme cases: [Renovating the home lawn](https://extension.colostate.edu/topic-areas/yard-garden/renovating-the-home-lawn-7-241/)
* [Homeowners guide to fertilizing your lawn and garden](https://extension.colostate.edu/docs/pubs/garden/xcm222.pdf) (PDF)
* [Homeowners guide to alternative pesticide management for the lawn & garden](https://extension.colostate.edu/docs/pubs/garden/xcm221.pdf) (PDF)
Let us know if you have other specific questions!
– Griffin