Under normal circumstances you will begin to notice your new grass beginning to develop roots and knitting to the ground. To check this you will lift a corner of the gras up. If you notice white roots coming out of the bottom side of the grass you have root development. At this point you can begin to mow. Make sure your mower blade is sharp.
Avoid taking off more than ⅓ of the current grass height in any single mow. Doing so will eliminate the need for clipping collection, allowing them to return to the lawn where they can decompose and return essential nutrients back to the soil.
Mowing heights will vary based on personal preference. Keeping your grass mowed at a higher height, assuming 2”, will provide for a deeper root system and will tend to hide fungus and weed problems if those are issues for you. Try to avoid mowing when the grass is still wet from dew in the early morning and evening.
Mow your lawn in a different direction with each mowing. Altering the direction of each mow ensures a more even cut since grass blades will grow more erect and less likely to develop a set pattern. Keep your mower blades sharp, which will mean getting them sharpened several times during growing seasons.
Selecting the right mowing height
For Seven Cites Sod Low Mow Blend of Kentucky Bluegrass of turfgrass it is recommended that the mowing height range in inches be between 1.5 and 3 inches and the optimal mowing height is 2 inches with mowing being done every 5-7 days.