Butterflies, along with many other pollinators, need all the help they can get. Arizona is on the migration route of the vulnerable monarch butterfly. In addition, we have 334 species of other native butterflies in the state.
Butterflies are insects that live on nectar and pollinate a large variety of plants while they feed. Many species have declined due to loss of habitat and the warming climate. A recent report noted that butterflies in the U.S. had declined at a rate of 1.6 % per year over the past 40 years. Warm fall seasons, in particular, are thought to be a major factor; the Southwest region of the U.S. has seen some of the greatest warming during the fall months making our area a difficult place for butterflies to thrive.
One way to help them out is to plant a butterfly garden. You will need to provide them with shelter, water and plants that are known to provide them with both nectar and an opportunity to breed. Here are the details.
What do you need in a butterfly garden?
Water: Butterflies like to drink from moist and wet soil, so the easiest thing to do is to water some bare soil and gravel areas in your yard to leave puddles for them. It may be easier to choose a large saucer, fill it with sand and gravel, and keep it watered. This way butterflies have access to water throughout the day. If you have a larger property, consider adding a larger water feature to help provide a cool and wet habitat that butterflies crave.
Shelter: Butterflies like trees and large shrubs for sleeping at night so they are protected from predators. Citrus trees and native trees such as hackberries are great. Trees in a neighbor’s yard or in the street can also serve that purpose. In addition, butterflies need more cool and wet spaces, and planting more trees can help cool down areas in the urban heat island.
Nectar plants: Flowering plants that produce lots of nectar are a great food source for butterflies and will also attract other pollinators like hummingbirds and native bees. Do not use plants that have been treated with systemic pesticides and don’t use pesticides in your garden, either. These chemicals harm insects, birds, lizards and other animals critical to our ecosystems and food supply.
Host plants: These are plants that butterflies lay eggs on which serve as food for their caterpillars. Again, it is critical that you use plants that haven’t been treated with systemic pesticides so that these chemicals don’t harm the caterpillars. In addition, be prepared to have caterpillars in your garden, and don’t kill them when they appear. Butterflies and plants evolved together, and most plants will recover even if their leaves are gone for a period of time due to caterpillar appetites. Host plants will look munched on, so don’t plant them for their looks.
What plants to choose for your Tucson butterfly garden
Here is a partial list of plants you can use in your butterfly garden. If you have limited space, choose plants that fulfill multiple roles, for example ones that act as both nectar plants and host plants. If you want to qualify as a registered monarch waystation through Monarch Watch you will need to plant at least 10 milkweeds.
Host plants
Expect caterpillars and leaf munching on these plants.
- Desert or rush milkweed (Asclepias subulata). This plant is native to our area and thrives in full sun with little water.
- Pineneedle milkweed (A. linaria). This milkweed prefers part shade and needs a bit more water.
- Arizona milkweed (A. angustifolia). This plant also prefers some shade; don’t plant in afternoon sun.
- Fairy duster (Calliandra eriophylla). This wonderful little native shrub has beautiful pink fuzzy flowers and thrives on neglect.
- Desert hackberry (Celtis ehrenbergiana). Large shrub with thorns, may need a bit of extra water.
- Canyon hackberry (C. reticulata). A large native tree that provides habitat for many native species.
- Citrus trees (Citrus spp.) The fragrant blooms are also great for nectar production.
- Desert senna (Senna covesii). A small shrub with lemon yellow flowers and rounded green leaves. Will self-seed after planting.
- Sunflowers (Helianthus spp.). These annuals are also nectar plants.
- Globe mallow and other mallows (Sphaeralcea spp.). These plants are also wonderful for native bees.
- Anacacho orchid tree (Bauhinia lunarioides). A Chihuahuan Desert native tree which can also grow as a small shrub and has beautiful white flowers.
- Daleas (Dalea spp.) Lovely purple and violet flowers; very sun and drought tolerant.
- Velvet mesquite (Prosopis velutina). Native tree common to washes which provides lots of habitat.
Nectar plants
These are too numerous for an exhaustive list, but here are a few. Note that many host plants are also nectar plants and provide food for both adult and larval stages.
- Desert lavender (Condea emoryi). Light lavender flowers. Does well in sun.
- Bee brush (Aloysia gratissima). Lacy growing habit and light creamy fragrant flowers.
- Wooly butterfly bush (Buddleja marrubiifolia). Fuzzy light grey-green leaves and orange spherules of flowers. Very sun-tolerant.
- Red bird of paradise (Caesalpinia pulcherrima). Not a native, but has lots of nectar which also attracts hummingbirds.
- Queen’s wreath vine (Antigonon leptopus). This beautiful light pink vine is winter deciduous.
- Desert broom (Baccharis sarothroides). Plant male plants to avoid seedlings.
- Mist flower (Conoclinum spp.). Lovely light violet flowers attract tons of butterflies of various species.
- Lantana (Lantana spp). Easy to get at nurseries, but make sure you’re not buying ones treated with pesticides!
- Salvias (Salvia spp.) Bees and hummingbirds love these, too!
For many more plants, check out Spadefoot Nursery’s list of butterfly plants for Arizona.
Other butterfly garden resources for Southern Arizona
- Citizen scientists can help out by signing up on e-Butterfly to help observe and record butterfly populations in their area. This helps scientists track how different species are doing in various geographical areas.
- The Southwest Monarch Study’s guide, Low Desert Monarch Waystations and Butterfly Gardens. I also recommend their Facebook page.
- Central Arizona Butterfly Association’s guide to Butterfly Gardening.
- Arizona Native Plant Society Guide to Selecting Plants for Pollinators.
- Butterfly lovers can also check out this great Arizona State Parks site with tips on how to identify butterfly species and a list of parks where you can observe them.