Seedlings rapidly establish and form a short tuft. Plants rapidly spread vegetatively by rhizomes and tillers forming a sod. Rhizomes represent important carbohydrate sinks for Kentucky bluegrass. Most rhizomes develop just below the soil surface. Those developing at and slightly above the soil surface turn downwards.
Rhizome elongation is dependent on environmental conditions.
Short rhizomes are produced under low moisture conditions, resulting in numerous, closely spaced plants. Under adequate moisture conditions, internodes will be longer, resulting in more widely scattered new shoots. One plant can spread to occupy and area 2 m 2 in 2 years. Tillering is induced by photoperiod and temperature and modified by soil moisture, nutrients, and defoliation. Production of tillers of Kentucky bluegrass is enhanced by relatively cool temperatures and short photoperiods.