I am not sure if my love for gardening is separate from my love of butterflies or if one developed from the other. By planting butterfly-friendly plants and flowers in my garden, I attract more butterflies and caterpillars. Then I get to indulge my love of butterflies. It is a win-win for me.
The first thing you have to learn is about which butterflies are native to your area. You can have all the plants necessary for your favorite butterfly to enjoy but if they are not present in your area, you will have wasted a lot of effort. Here is a handy map you can use to find the butterflies most likely to visit your yard. This way, you can plant accordingly.
There are two methods to attracting butterflies, although you can use a combination of the two. You can plant the things that caterpillars like to eat, which will attract butterflies to your yard to lay eggs. You can also plant flowers that will attract butterflies to their nectar. If you plant a combination of the two, you may be able to observe the entire life cycle of a native butterfly right in your backyard!
Butterfly host plants, or what I call caterpillar food, are the ones butterflies will lay eggs on. I recommend only the stout of heart gardener tolerate host plants because you have to not mind the fact that your plants being chewed on! There are a few varieties of caterpillar that enjoy willow or alfalfa. If you stick with native plants, they will be easier to take care of.
If you only want butterflies, or if you want the caterpillars to remain in your garden, you need flowering plants to provide nectar. Many people like butterfly bush for this purpose, but it is not native to the United States and it can overrun not just your garden but the yards around you. However, flowers like butterfly weed (not actually a weed), zinnia, marigolds, lavender, cosmos, sunflowers, asters, thyme, sage, and even oregano will attract butterflies to your garden. You will likely find one of these more native to your area and easy to grow. Aim for your flowers to be blooming in mid to late summer, when butterflies are most active. For a much more extensive list that is broken down by the butterflies they attract, you can look here. Personally, I like a combination of herbs and flowers in my yard. This way not only does it look pretty but it tastes delicious too.
If you plant the host plants near the flowering plants, you will create a perfect habitat for butterflies to live out their entire lives inside your garden. You will also have a beautiful garden for yourself to enjoy!