Grain sorghum, commonly known as milo, is a resilient crop valued for its exceptional tolerance to heat and drought. Its deep root system and efficient water use allow it to maintain productivity even when other grain crops struggle. While milo is adaptable, the timing of planting remains the single most important factor for ensuring a successful stand and maximizing the final grain yield.
Minimum Soil and Temperature Requirements
The earliest time to plant milo is governed by the soil temperature. Milo is a warm-season crop, requiring a minimum soil temperature of 60°F for successful germination and emergence. For the best stand uniformity, experts recommend waiting until the soil consistently reaches 65°F at the planting depth. Planting into cold, wet soil carries significant risk because low temperatures slow the seed’s metabolic rate, delaying emergence and leaving the seedling vulnerable to soil-borne diseases. To accurately gauge readiness, soil temperature should be measured at the planting depth (1 to 2 inches) between 10:00 a.m. and noon, and ideally, the temperature should have held at or above the minimum for three consecutive days.
Timing Adjustments Based on Regional Climate
Translating the temperature requirement into a calendar date results in a wide planting window that shifts dramatically across different growing regions. The optimal window for planting milo generally spans from mid-April through mid-July, dictated by local climate patterns. In the Mid-South, planting often occurs between May 1 and June 1, while in the Southern Plains, planting may begin earlier in April or be delayed until June to manage water resources. Conversely, in the Northern Plains, planting is typically delayed until mid-May or early June due to shorter growing seasons and slower soil warming. Growers also adjust planting time based on the intended purpose of the crop; while earlier planting maximizes grain yield, later planting may be acceptable for forage or silage.
Dealing with Delayed Planting
When conditions prevent planting during the optimal window, growers must consider the latest acceptable time to plant milo. Planting too late increases the risk that the crop will not mature before the first killing frost. To mitigate this, delayed planting necessitates selecting shorter-season hybrids that require fewer growing degree days to reach maturity. Another adjustment for late planting is to increase the seeding rate by about 15 to 20 percent. This higher initial plant population compensates for the reduced time milo has to produce productive tillers.