If you’re planning to sow garlic this month, you’re already on the right track, but most gardeners completely miss the window. Spring planting produces stunted, undersized bulbs, whilst autumn sowing yields hefty, flavour-packed harvests. Here’s why timing is everything, and what you need to do right now.
Across the UK and US, late summer marks the beginning of garlic season, yet many home gardeners remain firmly stuck in spring-planting mode. Right now, perceptive gardeners are sourcing seed garlic, preparing beds, and planning October and November plantings. Meanwhile, others are still waiting for spring, completely unaware they’re about to waste an entire growing cycle.
Garlic is a cold-season crop with a non-negotiable biological requirement: it needs sustained chilling over winter to trigger bulb formation. Plant in spring, and the plant races straight to flowering without developing a proper bulb. Plant in autumn, and the clove spends months underground, accumulating the vernalisation hours necessary for the bulbing response that follows.
The difference in results is stark. Autumn-planted garlic produces bulbs 40 to 50 percent larger than spring-planted equivalents, with sweeter, more complex flavour compounds developed through the extended growing season. A single bulb planted in October will yield six to ten substantial cloves by June. A spring-planted clove typically produces a single, golf-ball-sized bulb at best.
You have roughly six weeks to get organised before the autumn planting window opens in earnest.
As September arrives, watch soil temperatures closely, aiming for consistent readings below 15°C before planting. Moisture levels matter too, particularly in August and September, so water thoroughly if rainfall is scarce. By November, your autumn plantings will be establishing roots, and next summer will reward your foresight with exceptional garlic.
