I don't understand the connection between a raised bed and planting to attract butterflies?
When it comes to attracting butterflies, they're easy and actually I don't spend one cent to attract them with plants that grow naturally in my area, two really good examples of this are my native Spanish needle (
Bidens alba) and Snow Squarestem (
Melanthera nivea) plants, which are both naturally growing in my area and not only attract butterflies in droves, but many other pollinators.
However, to take any butterfly garden to the ultimate level, you must learn the host plants and plant them and eventually butterflies will become a nuisance insect.

I planted a host tree for the Cloudless Sulfur butterfly and I saw my first Chrysalis this year, less than a year from planting the tree.
And I've seen a record number of Monarch caterpillars becoming butterflies this year -- this is the time of year they have the best chance for survival, because the wasps are still making their nests, so their only food source is nectar, because they don't have any larvae to feed.
Again, this is where many "weeds" can play a part. A good example in my area is the Pellitory (
Parietaria judaica) and False Nettle (
Parietaria judaica). I got tons of Red Admiral butterflies around. Not to mention other butterflies, including the Monarch, which supposedly is endangered, but you wouldn't know that from my yard, it's the most common butterfly.