Bindweed and watering

Asked July 6, 2019, 9:40 AM EDT

I have two questions I would like to ask. 1. I have bindweed that I would like to kill, without dangerous chemicals. I have pulled all I see, so far, so I know the bugs that eat it (and need a lot of it) won't work. Is there something you can apply that will kill the whole plant? We have a young Blue Spruce tree in a xeriscape front yard that does not hook up to our sprinkler system. How much water does it need, and how often (if it has not rained)? Is putting about 4 gallons, twice a week, enough or would setting a hose on slow flow better? Thank you so much!

Adams County Colorado

3 Responses

For the blue spruce, we recommend applying 10 gallons of water per inch of trunk diameter. The interval for watering depends on the temperature and precipitation. You can check soil moisture with a screw driver or your thumb and water when the top couple of inches of soil are dry. The method you are using sounds like it pretty much would fit the recommendation.

For the bindweed, there is no easy solution. You can ware it out by repeated pulling but it may take several years of vigilant weeding. Quinclorac, which is the active ingredient in many products labeled "crabgrass killer" is fairly effective. It can harm other broad leaf plants but will not affect cool season grasses like bluegrass. If you choose to go this route make sure to follow all the instructions for application on the label of the product.

I hope this helps, please let me know if you have further questions..

Thank you for this information! I have one more question for you. We have a lot of earwigs and they are decimating our salvia and chard. Will a granule insect killer we used on grass to reduce insects work around these plants? I know I can't use around food plants like chard, but is it doable for the salvia?

Without knowing the active ingredient of the pesticide I cant say if it will be effective. In terms of where you can use the pesticide safely, the label will tell you where it is and is not allowed to be used (break out your reading glasses).

We have a fact sheet which discusses earwigs including how they can be controlled. You can find it here: https://extension.colostate.edu/topic-areas/insects/european-earwigs-5-533/

Hope this helps!