Q.Why doesn’t my milkweed flower and develop pods?
Milkweed grows on the west side of the house where it gets more than eight hours of sun each sunny day. It also gets plenty of water from an irrigation system. It seeded itself in that location – I did not plant it, although I had been wanting to grow some. This is the third year it has come up in that location and expands every year. But no flowers and no pods. Why?

Certified GKH Gardening Expert
If there is excess nitrogen in the soil the plant may not flower, so do not fertilize milkweed. Also, milkweed may not bloom if the plant is stressed, such as by drought or excessive heat. The caterpillars eat the leaves of the plant, so your milkweed can still be a host plant without flowers.
Have you identified which kind of milkweed it is? Asclepias tuberosa likes a sunny, dry situation, whereas A.incarnata prefers more moisture. A good website to identify milkweed is monarchwatch.org.
https://www.gardeningknowhow.com/ornamental/flowers/milkweed/growing-milkweed.htm