The warning is even written on the bag of weed and feed products, but some people do not read the labels and what those homeowners do not know can kill their trees.
"If you use it consistently enough, in two to three years, you can for all intents and purposes kill a tree because you are burning its roots," said The Gardenline's Randy Lemmon.
Randy Lemmon knows all about the impact of products that feed the lawn and kill the weeds. As the host of the GardenLine radio show, Lemmon says this time of year some callers are asking what's wrong with their trees.
Even the makers of weed control and lawn feeding products know the chemicals can be harmful for trees. The directions on the bag make it clear, "do not apply on or under the branch spread (rootzone) of trees, shrubs, bedding plants, flowers or garden plants."
Lemmon says the reason trees can be hurt is the active ingredient Atrazine.
"While it works at killing weeds, it is what you don't know and don't see that it is damaging, the root systems of trees, the root systems of shrubs nearby," Lemmon warned.
Louis Flory has run a tree service for 30 years. He says every few weeks a homeowner calls with a sick tree.
"I probably see it about once a month during the hotter temperatures," Flory said. "The infant roots pick up the microscopic feeder roots pick up the pre-emergent and it burns the feeder roots and throws the tree into distress."
Flory says homeowners can use the product for years without a problem and then see trees nearly die in a matter of days.
We contacted Scotts, the maker of one of the most popular weed and feed products. The experts there stress homeowners should read the instructions before using the product and add if you use it correctly, weed and feed will give you the results you are looking for. They do not recommend using weed and feed under your trees or shrubs.
What should you do if you have been using these products and are worried about your trees?
- First, stop using the products if the directions say don't put it near trees or shrubs
- Next, water thoroughly
- After the temperature is back above 75 degrees, water three times a week to dilute the chemicals
- And you may want to speak with a certified arborist too
We have a link to the Harris County Master Gardeners Web site and they can ask answer questions too.