Monarch butterflies are becoming more and more scarce, and it’s up to humans to help them. In the past 30 years, the number of monarchs has decreased by 90%, as has the number of milkweed plants (Asclepias spp. and cvs., Zones 3–9). Milkweed is the only source of food for the monarch caterpillar. The decline in milkweed is mostly due to increased use of pesticides, which affect the number of pollinators, and also weather and deforestation.

Although native, common milkweed (A. syriaca, Zones 3–9) can be grow quite aggressively in the Southwest, which is why milkweeds can have a bad rap here, but there are over a hundred milkweed species native to the United States. Milkweeds are perennial and have a diverse range of heights, colors, and soil preferences, although most prefer full sun. I have several favorite milkweeds that I enjoy growing in my Tucson garden. I enjoy them even more knowing that I’m helping rebuild the monarch population one plant at a time. Here are two milkweed species that you should consider adding to your Southwest garden.

Tropical milkweed is a tender option with bright midsummer blooms

Tropical milkweed (A. curassavica, Zones 8–11) is native in South America, Central America, and Mexico but grows well in the American Southwest. ‘Silky Gold’ tropical milkweed (A. curassavica ‘Silky Gold’, Zones 8–11) is a cultivar that will bring a little bit of sunshine to your garden with its bright yellow blooms. It loves full sun, blooms throughout the summer, and quickly grows 3 to 4 feet tall and 2 to 3 feet wide. This herbaceous perennial is the perfect addition to any meadow area or garden border.

‘Red Butterflies’ tropical milkweed (A. curassavica ‘Red Butterflies’, Zones 8–11) is a show-stopper, with bright red and gold clusters of flowers. It is extremely low maintenance and can handle poor soil. Reaching 2 to 3 feet tall and 1½ to 2 feet wide, it looks especially beautiful in less manicured, wilder garden designs.

Butterfly weed is a more compact option, with vivid orange flowers

Butterfly weed (A. tuberosa, Zones 3–9) is a hardier option, with beautiful bright orange flowers that attract butterflies. This plant produces a lot of nectar. It’s a quick grower but more petite than many other milkweeds, growing to roughly 1 foot tall and 2 feet wide. This low-maintenance milkweed loves full sun and can tolerate drought, especially once established. It can also handle a multitude of different soils and terrains.

Plants that are not just beautiful but also support butterfly population growth are important to have in your garden, especially considering the sharp decline of monarch populations over the years. So if you plant one new plant this year, make it a milkweed. For more native milkweed options, check out Grow Native Milkweeds to Bring Pollinators to Your Garden.

—Laurel Startzel is an interior designer and container garden designer. She is a former co-owner of Denver Dirty Girls, a container gardening business, and lives in Tucson, Arizona.

Fine Gardening Recommended Products

The Crevice Garden: How to make the perfect home for plants from rocky places

Fine Gardening receives a commission for items purchased through links on this site, including Amazon Associates and other affiliate advertising programs.

A crevice garden replicates the environmental conditions of mountain tops, deserts, coastlines, and other exposed or rocky places on earth. These striking garden features provide perfect conditions for the plants native to these far-off places, bringing the cultivation of these precious gems within everybody’s reach.

Buy at Amazon

Berry & Bird Rabbiting Spade, Trenching Shovel

Fine Gardening receives a commission for items purchased through links on this site, including Amazon Associates and other affiliate advertising programs.

Ideal Tool for All Gardeners Use: Our heavy duty trenching shovel is designed by a professional gardening tool designer. Lifetime Durability: This heavy duty drain spade is made of high-quality stainless steel, it is very strong and durable, even if it is used for high-strength work, it will not bend. Ergonomic Wood Handle: The handle of this planting spade is made of ash hardwood harvested from FSC-certified forests and has an ergonomically streamlined design, making it very suitable for everyone's hands. Multi-Use: This digging shovel is generally used for digging trenches, digging holes, transplanting, edging, moving compost, cutting thick turf and furrowing. The sharp blade allows you to cut, scoop, dig, lift and dice in hard soil.

Buy at Amazon

Monarch Butterfly Rescue Wildflower Seeds 4 oz.

Fine Gardening receives a commission for items purchased through links on this site, including Amazon Associates and other affiliate advertising programs.

HIGH QUALITY SEEDS and EXPERT GUIDANCE: Experience the quality seed difference. We are committed to providing the highest quality, open-pollinated, non-GMO/non-GE seeds to our customers, guaranteed. A trusted source of high quality seeds since 1985. ATTRACT MORE MONARCHS: We know seeds and we know pollinators! Our expertly crafted botanical garden seed mixes contain a wide variety of both perennials and annuals that are specifically designed to attract pollinators. Attract more Monarchs and Butterflies in general. Gardener tested, pollinator approved! All Of Our Wildflower Varieties Are 100% Pure Seed, They come with complete planting instructions. Compare and see the quality value. This Wildflower Seed Mix will make the perfect gift for those gardeners in your life.

Buy at Amazon