I know nothing about growing snapdragons. I do know they are a host plant for the buckeye butterfly so you may see cute little caterpillars :-)

As for Asclepias, you'll get blooms the first year around late August early September. What variety are you planting?

Edna

Snaps are a breeze. Start them now!

GGG

Snapdragons are a cinch. If you plant them inside to start them, freeze them for about 48 hours before sowing them. Sow thinly and do not cover the seeds, but keep the light low. Germinate them about 70 F and keep them moist consistently until they come up. After that, you can keep them at about 60F; they like cooler weather. If you sow in February, you can get them off to a good start and blooming by May.

I think you'll love growing snapdragons, Cameron. They were one of my first successful "crops" as a child, and have been a favorite ever since. I especially like to plant the dwarf variety in front of the taller variety. They are a wonderful cut flower for bouquets. They bloom two or three times a year, and don't need a lot of water. In NM they are perennial! In California I had to replant every year.

I don't know about milkweed. I've never planted it, and it doesn't grow wild on my property. Monarchs visit my yard, as well as many other types of butterflies. There aren't many flower gardeners on the mesa, so it could be the butterflies are taking whatever they can get. I often see butterflies on the snapdragons.

A pair of small butterflies did their mating ritual on my right forearm last year. I stood there dumbfounded, and tried my best not to disturb them.

Lorna

I direct sowed Rose Milkweed in spring and it didn't bloom the first year. I also have the orange variety and it didn't get blooms last season either (last season being the first it was direct sowed). But both varieties seem to germinate easily.

Last year, I planted both milkweed (tuberosa and incarnata) and snapdragons. Even though I have a retail license, I'm not able to find a good source for milkweed plants.

The cats ate the milkweed with minimal blooms, but it still got full height. The snapdragons are still evergreen in my garden. They bloomed up until Thanksgiving. I just recently deadheaded those. Wonderfully drought and deer resistant, so I need more! I did notice some of the butterflies were very attracted to the snaps.

I haven't deadheaded the milkweed because it comes up so late here (June) that I need to keep track of the location.

Burpee has seeds for the tall snaps (I can only find short varieties locally in the nurseries) and they have seeds for three types of milkweed. They list all of those as "direct sow" when the night temps stay about 50. That would be late April or early May here.

I have a frost-free zone in my garden where I can start seeds. Petunia seedlings are already coming up there from past plants!