Host an Event Volunteer Join Tickets

Support the plant database you love!

Q. Who is Mr. Smarty Plants?

A: There are those who suspect Wildflower Center volunteers are the culpable and capable culprits. Yet, others think staff members play some, albeit small, role. You can torture us with your plant questions, but we will never reveal the Green Guru's secret identity.

Help us grow by giving to the Plant Database Fund or by becoming a member

Did you know you can access the Native Plant Information Network with your web-enabled smartphone?

Share

Ask Mr. Smarty Plants

Ask Mr. Smarty Plants is a free service provided by the staff and volunteers at the Lady Bird Johnson Wildflower Center.

Search Smarty Plants
See a list of all Smarty Plants questions

Please forgive us, but Mr. Smarty Plants has been overwhelmed by a flood of mail and must take a break for awhile to catch up. We hope to be accepting new questions again soon. Thank you!

Need help with plant identification, visit the plant identification page.

 
rate this answer
Not Yet Rated

Friday - July 20, 2007

From: Plano, TX
Region: Southwest
Topic: Seasonal Tasks
Title: Toxicity of horticultural oils
Answered by: Joe Marcus

QUESTION:

Is T&S dormant oil spray a toxic product? Our church (Prairie Creek Baptist in Plano, Texas) is transitioning to organic/native landscape. This is the product used by the current lawn service. Also, we would appreciate any other information to help us make this transition.

ANSWER:

Since we know of no brandname, T&S, we are assuming you mean trees and shrubs. This would make sense because trees and shrubs are the landscape elements that you would spray with dormant oil. The term dormant oil speaks more to the season in which it is applied -- during trees' and shrubs' dormant season -- than to a particular kind of oil. In the past, dormant oils were all petroleum-based, rather heavy oils that had to be sprayed in warmish weather during the winter. Scale, aphids, mites and other overwintering insects are the target pests for winter-application of an oil spray. Petroleum-based dormant oils can damage green (non-dormant) tissue. So winter annuals such as pansies, snapdragons and ornamental crucifers are often severely damaged by overspray or spray drift.

The toxicity of any dormant oil, or any other horticultural oil for that matter, can vary from product to product. So it is very important to fully understand the toxicity of the specific product that is being applied. Pesticide labels and Material Safety Data Sheets (MSDS) are your primary sources of information for pesticide use, safety and toxicity information. Your lawn service company must have MSDS sheets on file for each material they use. They will provide copies of those sheets to you at your request. If you have concerns about the safety of the material that is being applied to your church's landscape, you should meet with a representative of your lawn care company to discuss those concerns and look for solutions to any problems you identify.

 

More Seasonal Tasks Questions

Survivability of plants after freeze
December 08, 2003 - I have many beautiful plants that froze. Some were Lantana, Hummingbird Bush, Candlestick Trees, Esperanza, Some flowers, and Marigolds. I love all of my plants and flowers and I want them to grow bac...
view the full question and answer

Wildflowers planted in Pittsfield, IL to bloom the first of October
July 01, 2010 - If I plant my wildflower seeds now in Illinois, is it possible they will bloom in three months (by the very beginning of October)?
view the full question and answer

Arrows and Hunting Dogs in Kentucky
December 09, 2009 - Mr. Smarty Plants--Is it normal for our arrowwood viburnum to give off a musky odour in the late fall? The smell reminds me of a wet hunting dog.
view the full question and answer

Wildflowers for a wedding site
November 11, 2007 - My fiance and I would like to get married on his family's ranch, just north of Johnson City on the Pedernales river, in April of 2009. Currently, we are clearing the over-grown meadows of cactus and ...
view the full question and answer

Cutting back achillea in New York
March 18, 2009 - Last summer I planted three gorgeous hearty achillea with flat, yellow tops, about 3 feet high or more each, in my sunny garden. But after they were done flowering, I left those very pretty brown stem...
view the full question and answer

Support the Wildflower Center by Donating Online or Becoming a Member today.