Should I add iron

Asked September 7, 2019, 7:39 AM EDT

My lawn has been has been thin and a lighter green than other lawns in my area. I've used Scotts fertilizers for years. They used to be 30-3-3. For quite a few years now they have been 30-0-3. In the fall I would use Scotts 30-0-6 with sulfer. The grass would be stronger and darker green. In the spring the grass would do well early. Each year in late spring to early the lawn would uniformly yellow. This happened even though the 30-0-3 was used in early May and mid June. The lawn is also watered 1/2" to 1" in two watering a week. This year based on your soil test saying my lawn needed more P and K, lesco 12-24-18 was used for the June and late August feedings. The lawn is much thicker now. However it is still lighter green than other lawns in the area. Do you think adding iron would help make the lawn darker? I'm thinking of using Lesco 25-0-6 with 5% iron. The lawn does have some rust, less this year than the previous few. Otherwise it seems disease free to me. I'm attaching a picture. In the past few years a similar picture would be more yellow blades than green. I think it looks pretty good now but it still lighter green than neighbors. If this is not a good choice, would you recommend a fall fertilizer?

Wayne County Michigan

3 Responses

Can you send me your soil test code so I can take a look?

I made a mistake and tried to send the whole report. I guess that didn't work. Here is a number on my report "#JMDJY9". I hope it is the right one.

Hello Mark!

Since you are willing to support a high maintenance lawn (high quality, uniform, dense growth) I would definitely recommend fall fertilization. The table at the bottom of your soil test results provides a schedule for nitrogen application.

Based on your previous results with sulfur, iron application would be a reasonable next step. Sulfur lowers the pH, which increases iron availability to the turf, but the result is short lived.

https://turf.purdue.edu/sulfur-is-not-effective-for-lowering-ph-of-turfed-soils/

https://extension.psu.edu/turfgrass-fertilization-a-basic-guide-for-professional-turfgrass-managers

Iron is used in the production of chlorophyll, which is the substance that gives your lawn its green color. Since the fertilizer you identified provides supplemental iron, it will provide a short term increase in the amount of iron available to the turf, leading to a greener lawn. Supplemental iron can also be applied as a foliar spray. Foliar sprays provide more immediate results but these results don’t last as long.

Fall fertilization will also strengthen your turf against rust.

https://www.canr.msu.edu/news/labor_day_fertilization_and_rust_on_turf

A few additional actions may help your lawn keep its green. Sharpen your mower blades. Dull blades tear rather than cut the turf, leaving a wider edge to brown. Mowing turf to a height of 3” or more will not only to help with weed control and water retention, but will cause the turf to develop deeper roots. Those deeper roots can absorb more nutrients. Periodically aerate the lawn, to relieve compaction and allow water and air to better reach the root mass and stimulate growth.

https://www.canr.msu.edu/news/mow_high_for_weed_and_grub_control

https://www.canr.msu.edu/news/improving_soil_conditions_for_turf_with_fall_aeration

Regards,