Rivendell Tree Experts

Is Lawn Fertilizer Harming Your Trees?


Lawn fertilizer helps homeowners get the thick, lush grass they covet. Watch any lawn fertilizer television commercial, and it’s enough to get you off the couch and to the home improvement store in minutes. One easy application and my lawn will be the best on the street? Sign me up! Hold on one second — you have to read the fine print. Lawn fertilizer that includes weed killer is often dangerous for your trees. Applying it to the lawn above a tree’s root system could seriously harm and ultimately kill the tree. What’s the use of green grass if all your trees are dying?

What Is Weed and Feed?

Weed and feed is the term used to describe lawn fertilizer products that allow homeowners to apply one treatment that simultaneously kills weeds and promotes grass growth. While it’s an attractive marketing prospect and an effective product, sometimes it’s too effective. Weed and feed often contains chemicals to kill broadleaf weeds. The problem is that many deciduous trees have many of the same characteristics as broadleaf plants. Broadleaf herbicides can cause tree leaf discoloring or curling, branch death or complete tree death.

What Are Your Other Fertilization Options?

The worst time to fertilize your lawn with weed and feed is in the spring. This is when trees are working overtime to put out new shoots. Growth is easily stalled and reversed in the spring. If you wait until summer heat takes over, it might not affect your tree as greatly. To avoid damage to your trees, change your approach. If your grass is already healthy, simply pull out individual weeds or spot-treat them, and avoid applying weed and feed above a tree’s root system. Some roots can extend 30 to 40 feet from the tree’s trunk. If you aren’t sure how far your tree’s roots reach, talk to an arborist. They can help you identify the areas of your lawn to avoid when spreading strong chemicals. You can also use a nontoxic, organic, weed-killing product that doesn’t have the same damaging effect due to its lack of broadleaf herbicides.

The “Perfect” Lawn Includes Healthy, Vibrant Trees

If you’ve been spreading lawn fertilizer to the detriment of your trees, the first thing you should do is thoroughly water the soil surrounding the tree. Make sure to do this multiple times a week, especially if temperatures are rising. Diluting the chemicals will help reduce their effect on the tree.

In your effort to create the perfect lawn, don’t neglect the health of your trees! Once a tree is damaged from herbicides, it can take years to reverse. Discuss your lawn fertilizer options with your trusted local arborist, Rivendell Tree Experts, before you treat your grass. We can provide helpful, safe suggestions that mitigate and help prevent tree damage.