per Steve Solomon (adjust a little for Seattle):
September - Mid-October
Amend the top few inches of soil with lots of compost. Plant cloves root down, 1 inch deep, 3-4 inches in row, rows 18 inches apart (at least). If soil's rich, don't use fertilizer. If poor, use 2/3 strength.
Side dress with bloodmeal, 2-3 tablespoons every 5 feet, close to plants.
Side dress with fertilizer, clost to plants