Dahlia tubers typically take about 2 to 4 weeks to sprout green growth above the soil, though this can vary depending on factors such as dahlia variety, soil and air temperature, and planting time

. Some tubers may take longer, up to 6 weeks or even 8 weeks, especially if planted early in the season when the soil is still cool

. Warmer soil temperatures (around 60°F or 16°C) encourage faster sprouting

. If tubers are pre-sprouted indoors or in a warm, sunny location with moist but not wet conditions, sprouts can appear in about 10 to 14 days

. However, patience is important as some tubers naturally take longer to "wake up"

. In summary:

• Normal sprouting time: 2 to 4 weeks after planting in warm soil
• Possible range: 2 to 8 weeks depending on conditions and variety
• Faster sprouting with warm soil and pre-sprouting indoors
• Cooler soil delays sprouting and may extend it up to 6 weeks or more

This variability means gardeners should expect some tubers to sprout sooner and others later, and avoid watering too much early on to prevent rot