Despite the arrival of October, warm summer-like conditions returned for an encore this week. While the recent temperatures may not feel very fall-like, the landscape is progressively taking on an autumn appearance. This means that for most intents and purposes the best window for planting new turf from seed has passed for this season, and workable options for successful establishment are increasingly limited. Persistent dry conditions in some locations, especially the eastern part of the state, have further complicated some planting efforts. Late seeding projects on bare soil in the next couple of weeks should include substantial percentages of faster-establishing grasses such as perennial ryegrass.
Another solution that can extend the planting window is the installation of sod. While sodding is among the most expensive methods of establishment, it can also be the fastest when performed properly. The following are some important considerations in regard to turf establishment from sod:
- Sod selection: As with seed selection, turfgrass species and varieties in sod should be chosen based on site conditions, expectations and management resources. Keep in mind that sod will often, but not always, include a sizeable percentage of aggressively spreading (or "sod-forming") grasses such as Kentucky bluegrass. At present, available sod options from many growers offer more variety than ever before with turfgrass mixes and blends designed to fit a range of applications.
- Timing: Sod can be installed any time the soil is not frozen, but it is better when soil temperatures are conducive to rooting (generally greater than 50 degrees Fahrenheit). Installations during favorable growth periods such as mid-spring or late summer/early fall make post-plant care somewhat less burdensome and greatly increase the probability of success. Sod must be installed as soon as possible after harvest, ideally within 24 hours.
- Site preparation: Getting a site set to receive sod is essentially the same as for seeding projects. The most important aspects include incorporation of fertilizer and soil amendments based on soil test results, finish grading and preparation of a firm, granular seedbed (or in this case, "sodbed").
- Associated Soil: Ideally, the soil attached to the sod should be as close as possible to the soil on the planting site. This is not always achievable in practice, but the closer the match, the lower the potential for future layering problems. Washed sod can minimize such problems, but this specialized product is normally reserved for transplanting of field-grown sod to sand-based rootzones.
- Sod thickness: Sod is available in different thicknesses which typically range from approximately .5 to 2 inches thick. Thickness refers to the amount of soil present in the sod and does not include the associated turfgrass shoots or thatch. Different thicknesses suit different applications. In general, thinner sod establishes faster but has lower initial stability while thicker sod has higher initial stability but establishes slower.
- Irrigation: Deep irrigation sufficient to wet at least the top 6 inches of soil must be applied in conjunction with sod installation. Ample moisture encourages downward growth of roots into the soil and thereby promotes proper establishment of the sod. The sod itself can also be moistened (but not soaked) during the installation process. Follow-up irrigation must begin shortly after installation and continue in the days and weeks following planting. Consistent attention to watering is critical to not only ensure that the sod does not dry out, but also that it roots down and establishes effectively. Watering can be gradually tapered as the sod becomes further established.
Other best practices for sod installation:
This article originally appeared on the UMass Amherst website.
- Avoid cutting sod strips whenever possible, smaller pieces dry out faster.
- Lay sod with the seams arranged in a staggered fashion, and always perpendicular to slopes.
- Stake or staple sod on slopes greater than 10 percent.
- Roll sod as soon as installation is complete to ensure soil contact and eliminate air pockets.
- Fill in any seams that open with a compatible seed/soil/compost "divot mix".
- Mow after installation according to an appropriate mowing height and the "1/3 Rule".