Turf grow-in is a valuable time to rapidly establish and set the foundation for a putting surface that will exceed performance expectations and provide long-term high-quality turf conditions. Rapid turf establishment is important for golf course revenue generation, minimizing weed establishment, and transitioning to a maintenance input schedule.
The pre-plant phase of a grow-in helps facilitate rapid turf establishment but should also be utilized as a period in which beneficial root-zone properties can be imparted that promote plant health for weeks and years following establishment.
The pre-plant phase is an optimal time to incorporate plant nutrients, beneficial organics, and soil amendments that can improve soil bioactivity often devoid in high sand based rootzones. Controlled-release nutrients, primarily nitrogen and potassium, which are highly subject to leaching, should be incorporated in the root-zone during the pre-plant phase.
Consistent and predictable nutrient release promotes steady, measured growth desired during a grow-in. The inclusion of phosphorus and micronutrients is also important at this time.
Finally, incorporate beneficial organics and other soil amendments which improve cation exchange capacity, water utilization, and biological activity during the grow-in and into the maintenance period. These components should also be considered during aerification to replenish the desirable characteristics of these two materials in subsequent seasons.
Nutrient inputs following sprigging or seeding should be low, especially if controlled release nutrients have already been incorporated in the root during the pre-plant phase. Application rates to target are 0.25 to 0.5 lb N per 1000 sq ft.
A strategy to consider is alternating a granular nitrogen source with a granular blend that contains nitrogen, phosphorus, potassium, and micronutrients every three to five days during turf establishment. Begin liquid/foliar inputs after first mowing at low rates, and include plant health components that help guard against biotic stress, especially those biotic stresses associated with high frequency of irrigation and nutrient inputs. A fungicide application applied within the first month following sprigging or seeding has demonstrated remarkable turf health responses during the grow-in phase.
In summary, a grow-in is considered one of the most important periods in the turf management cycle. A well-designed program that includes desirable pre-plant and post-plant inputs helps ensure a successful outcome that also provides value in subsequent seasons. A link to a tested and vetted establishment program can be found below. Pictures and data demonstrating the performance of this program relative to an industry standard can also be found below.
Harrell's Grow-In Program vs. Industry Standard Programs Study
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Harrell's Grow-In Study Results
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