Knowledgebase

Castor oil against moles and seed germination #886983

Asked October 02, 2024, 6:01 PM EDT

Hi, I've been plagued by moles every fall since purchasing my home. We border a large park and have the added issue of having a hill which I understand moles like for their tunnels. Each fall, in an effort to attempt a nice lawn, I have aeration and overseeding done. This year in particular the moles seem very active, having created tunnels throughout. I've read that using a mixture of castor oil & dawn can be effective to drive them out but cannot seem to find data about any impact to seed germination. Would you have any thoughts on that? Thanks in advance!

Hillsborough County New Hampshire

Expert Response

Hello Nicole,

Thanks for reaching out to the UNH Extension Infoline. First, we have a resource on moles and voles which might be helpful to you-

https://extension.unh.edu/blog/2018/03/mole-or-vole

Next, I found one resource that claims that castor oil has some limited efficacy on repelling moles in a lawn. For more information about that, see this resource-

https://extensionpubs.unl.edu/publication/g1538/2010/html/view#target12

The most effective control methods involve treating for lawn grubs which is a big food source for moles and then trapping if that doesn't work.

I hope this helps and please ask if you have any further questions!


Thank you for contacting the Yard and Garden Infoline, a service of UNH Cooperative Extension Replied October 04, 2024, 10:53 AM EDT
Hi Sean, thanks. I have the majority of this information. 
My question was if castor oil inhibits grass seed germination and growth. Is this something you can answer? 
Thanks 
Nicole 


Nicole M. Andersen 
617.285.9800


On Friday, October 4, 2024, 10:53 AM, Ask Extension wrote:

The Question Asker Replied October 04, 2024, 12:02 PM EDT

Hello Nicole,

From my research, it seems that castor oil will not harm your lawn. Despite this, you may want to try a small area first to see what effect it has before you use it on your whole yard. What I have seen is that once you apply the castor oil, it is suggested that you thoroughly water it in so that the oil seeps into the soil, which should deter moles due to the smell.

Here is an article that I found that explains how to use castor oil on a lawn-

https://www.mlive.com/advancenewspapers/opinion/2013/04/lawn_and_garden_moles_can_be_c.html


Thank you for contacting the Yard and Garden Infoline, a service of UNH Cooperative Extension Replied October 07, 2024, 3:08 PM EDT

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