Why are the tips of our ornamental onions turning yellow?

Q: Why are the tips of our ‘walking onions’ and our ornamental large alliums turning yellow?

Without additional information I am going out on a limb to assume this is not a disease, but rather but a cultural disorder.

It may very well have to do with soil fertility, which may be causing a potash deficiency. Certain types of soil will give you this problem, such as sandy loam. This can be verified by a simple soil test.

You can apply compost to the soil, which should help with moisture retention and also supply some nutrients.

Prior to planting, incorporate an all-purpose fertilizer, such as 6-8-6, into the soil. Once plants are established (about 6 to 8 weeks) do a side-dressing, such as 21-0-0.