Onions grow best in sandy loam or peat soil. The root system is weak, so fertilize and water close to the plant. The size of the bulb will be proportional to the size of the plant. Water and fertilize well in early stages
Hints:

Start indoors.

Transplant 5- to 8 cm [2-3"] apart in rows 30 to 45 cm [12-18"] apart.

In the fall, bend tops to hasten ripening.

Walla Walla Sweet Spanish - 115 days. This is an over wintering variety. Bulbs are flattened globes with thin yellowish-brown scales. This onion has a very mild flavour, designed only for an early June market as it does not store well beyond 1-2 months after harvest. It should be seeded in late September for best results. Popular transplanting variety for the home gardener.