March 01--My landscape contractor sodded my lawn last November and it is now looking very brown. Do you think it has died? Is there anything that I should be doing to help it if it is not dead?
-- Rachel Sorenson, Northbrook
In my experience, it is common for newly sodded lawns to be more brown-looking than the surrounding established lawns are in the first spring after sodding, especially when the sod is installed late the previous fall. This is a natural occurrence and does not necessarily indicate any problems with your lawn. If there is little snow cover and temperatures fall below 20 degrees Fahrenheit for several nights, the lawn will typically turn brown. The colder the temperatures are and the more cold nights that occur, the browner the turf. Parts of the lawn that are protected, or had snow cover for a longer period of time will often remain greener. This brown appearance is likely because the lawn's root system is not yet completely developed. That would explain why lawns that are sodded in summer and not fertilized in the fall are browner than lawns that received fall fertilization. Fall fertilization promotes root growth and more carbohydrate storage.
If your new lawn has a pattern of brown patches or sections, that is an indication that some parts of the lawn may not have established and died out, or there is damage from grubs or a disease like snow mold. For best establishment, the sod needs time to properly root in to the new soil. Because you installed your lawn in November, the lawn is likely not well rooted yet. The late, warm fall last year did provide better conditions for the turf's roots to develop than a normal Chicago fall. It will be best to minimize traffic on it as the frost comes out of the ground and when it is wet, to avoid leaving ruts in the ground, which will lead to an uneven lawn in the future. Avoid aerating your lawn until fall or next spring when the lawn is fully established to avoid pulling up the rolls of sod that are not yet rooted.
More established lawns that were installed with sod can also take on more of a brown cast in late winter and take longer than other lawns to green up in spring because of a large amount of thatch. Thatch is a loose, mixed organic layer of dead and living shoots, stems and roots that develops between the zone of green foliage and the soil surface. Thatch build-up begins when turf produces organic debris faster than it can be broken down. I normally do not recommend power raking a lawn, but this can help in lawns that have excessive thatch build-up. Then core aerate the lawn. Power raking for one to three years plus aerating annually should get the excessive thatch under control in most cases. Your lawn should green up later in spring once the weather is consistently warm.
Tim Johnson is director of horticulture for the Chicago Botanic Garden in Glencoe; ctc-realestate@tribune.com.
