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.

Yellow Utah Sweet Spanish - 115 days. A very large dark yellow globe. Flesh moderately firm and mild. Used extensively for slicing and hamburger purposes. Popular with home and market gardeners because of large size and mild flavour. Large green foliage has some thrip tolerance.