Sorghum (Sorghum bicolor) is a robust cereal grain, forage, and syrup crop. This grass species is valued for its remarkable tolerance to heat and drought, making it a reliable food and feed source in diverse and challenging climates. While commercial production often relies on large-scale machinery, sorghum is well-suited for small-scale cultivation using simple, non-mechanized planting methods. This guide focuses on the manual process of planting sorghum from seed.
Preparing the Planting Site and Timing
Successfully planting sorghum begins with selecting the right time and preparing the soil environment. The crop is frost-sensitive and requires warm conditions for rapid, uniform emergence, so planting should be delayed until the risk of the last frost has passed. The optimal time to plant is when the soil temperature consistently measures between 60°F and 65°F (16°C and 18°C) at the target planting depth, measured in the early morning.
Sorghum thrives in full sun, and the planting site should be chosen accordingly. While the plant adapts to a wide range of soil types, well-drained soil is preferred to prevent water saturation around the young seedlings. Sorghum is sensitive to low soil pH, so a soil test ensuring a relatively neutral pH is beneficial for maximizing growth potential. Before planting, prepare the ground by breaking up large soil clods through light tilling or raking to create a fine, loose seedbed suitable for manual placement.
Step-by-Step Manual Seeding Techniques
Select the appropriate seed, whether it is a grain, sweet, or forage variety, and ensure it has a high germination rate. For small-scale manual planting, a precision drop method is more efficient than broadcast seeding, as it allows for better control over plant density. Use a hoe or a finger to create shallow holes or a small furrow in the prepared soil.
The ideal planting depth for sorghum seed is 1 to 2 inches (2.5 to 5 cm); use the shallower end for heavy soils and the deeper end for sandy soils. Placing the seed deep enough to ensure contact with consistent soil moisture is more important than hitting an exact measurement. For grain sorghum, aim for a final in-row spacing of 4 to 8 inches apart after thinning, which corresponds to a final plant population of 40,000 to 70,000 plants per acre in dryland environments.
Row spacing can vary from 15 to 30 inches (38 to 76 cm), with narrower rows often leading to faster canopy closure and better weed suppression in small plots. Once the seed is placed, gently cover it with soil and lightly firm the surface with the back of a hoe or your foot. This firming action ensures good seed-to-soil contact, which promotes efficient water absorption and successful germination.
Essential Care for Early Sorghum Growth
After the seeds are sown, consistent moisture is necessary to support germination. While sorghum is drought-tolerant once established, young seedlings are vulnerable until their roots develop. Water the soil lightly but thoroughly immediately after planting, and maintain a moist environment until the seedlings emerge, which occurs within 5 to 12 days depending on the soil temperature.
Weed competition poses a significant threat to early sorghum growth, as the seedlings are initially slow to develop vigor compared to many weeds. Since manual planting often precludes the use of pre-emergent herbicides, dedicated hand-weeding or shallow cultivation between the rows is important to prevent weeds from outcompeting the young plants for light, water, and nutrients. Weed control is important until the sorghum reaches the five-leaf stage, when it begins its rapid growth phase.
Once the seedlings reach 4 to 6 inches and have established their first true leaves, they should be thinned to their final desired spacing. Thinning involves removing the weaker or excess plants to achieve the target in-row spacing. This ensures the remaining plants have sufficient resources for optimal growth and directs the plant’s energy into producing a robust stalk and a single, large seed head.