Ten ways to save monarch butterflies

It's April, the time of the great monarch butterfly migration from Mexico to Canada. But the great monarch butterfly migration is not so great anymore, because the number of monarchs has plunged in the last decade.  Luckily, there are ways to help. Here are our top ten:

1. Plant milkweed. Scientists chiefly blame monarchs' rapid decline on the widespread loss of milkweed plants. It's the only plant on which monarchs will lay their eggs, and the primary food for their caterpillars. Plant as many native milkweeds as you can, and as many different milkweed species as possible. Here are several options:

• Butterfly milkweed (Asclepias tuberosa): Butterfly milkweed has an orange bloom as stunning as a monarch's wings, and other butterflies, such as queens, both feed from its nectar and lay eggs on it. This plant does not grow well in gumbo soil, though. Best to plant it in a well-drained bed that is not overwatered. Some local nurseries carry butterfly milkweed, but call ahead to ensure that it's available.

• Mexican milkweed (Asclepias curassavica): Mexican milkweed is easy to find. It's not native, but planting it still helps monarchs. Be sure to cut back this type in December. It blooms longer than our native milkweeds, and scientists theorize that its longer blooming cycle can cause monarchs to stay too long in Houston and die in cold snaps. After the Mexican milkweed is cut, it will still grow back from the root and bloom again.

• Antelope horn and green milkweed (Asclepias virdis and Asclepias virdiflora): These are great milkweeds for monarchs, but they are challenging to find. If you can't find plants at a local nursery, you can purchase seeds through a native seed distributor such as Native American Seed near Junction, Texas.

• Common milkweed (Asclepias syriaca): Common milkweed grows all along the monarch's migration route. It produces a pale purple cluster of florets that emit large amounts of nectar that benefit monarchs and many other pollinators. Like antelope horn and green milkweed, this milkweed can be challenging to find, so you may need to purchase it from Native American Seed.

• Swamp milkweed (Asclepias incarnata): Swamp milkweed needs a lot of water, so plant it by a pond. Though once common, swamp milkweed is also now challenging to find but can be purchased through Native American Seed.

2. Don't kill caterpillars. To state the obvious: You can't have butterflies without them. Monarch caterpillars have yellow, black, and white tiger stripes.

3. Let caterpillars feed. Your milkweeds will show the lacy fringes of caterpillar feasts. Consider those chewed leaves a sign of success! And if you don't like the chewed look, comfort yourself that it won't last long: Milkweed has evolved to grow back its leaves after a couple weeks.

4. Plant native flowers. Adult monarchs need nectar, and the nectar they consume here in Houston gives them the energy to reproduce and make the long migration to Mexico. Non-native plants such as roses, azaleas, and daffodils do little if anything for monarchs. So instead, plant natives that monarchs evolved alongside — plants such as blue mistflower, prairie verbena, lantana, fall-blooming aster, basketflower, and goldenrod. These native plants will offer monarchs much more nectar than non-native plants. (The first three in our list can be found at most local nurseries, but the last three may need to be purchased through Native American Seed.)

5. Plant native grasses and shrubs. Butterflies need shelter from overheating, cold weather and predators. Plant a pocket prairie of Indian grass, Gulf muhly, little bluestem, and other native clump-growing grasses that are not meant to be mowed. Or plant them in beds where you'd use tall non-native ornamental plants, such as Mexican feathergrass or pampas grass.

6. Don't spray or sprinkle pesticides. Pesticides kill the eggs and larvae of monarch butterflies, so if you use them, you are directly harming monarchs. Even if you spray another plant, such as a rose bush on the far side of your yard, pesticide can get windblown and leave a residue on your milkweeds that will harm the plant and its monarchs.

7. Create a butterfly bath. Pour a mixture of sand and gravel onto a plate or a clay flowerpot saucer. Combine a cup of water and a quarter cup of apple or orange juice and pour the solution onto the gravel and sand. Set your butterfly bath somewhere in your yard (preferably in filtered sun during summer months) and monarchs may come to drink. Refill the bath as needed, making sure the sand is only damp, rather than covered in standing water.

8. Give your monarchs treats. Set a peeled banana or other fruit on a plate or clay flowerpot saucer near your butterfly bath. A butterfly cannot ingest fruit flesh with its proboscis, but it can extract juice from old fruit. Choose a brown banana or past-their-prime grapes, strawberries or apples. Roll an orange along a counter or between your palms to help release its juices, then cut it into quarters to set out. For other fruit, it's a good idea to mash it a bit first. The fruit you set out may attract gnats. Instead of seeing this as a problem, remember that drosophilia are food warblers and hummingbirds. And it's great fun to watch a ruby-throated hummingbird zip back and forth above a fruit plate, picking out drosphilia hovering above a banana.

9. Write or email your legislator. Let him or her know that you care about conserving habitat and helping solve the problems we have created for monarchs and other species. Start local, with city and county politicians.

10. Join butterfly-loving groups. National Monarch Watch (monarchwatch.org) provides free milkweeds to schools and nonprofits. On its site, you can report monarch sightings, find out more about supporting monarchs in your backyard, and donate to help restore monarch habitat. The North American Butterfly Association (naba.org) supports all butterflies, and its Butterfly Enthusiasts of Southeast Texas chapter is based in Houston.

Elizabeth White-Olsen is the director of Houston's new writing center, Writespace.

Glenn Olsen teaches landscaping, gardening, and bird identification at Rice University's Glasscock School of Continuing Studies, Houston Audubon, Katy Prairie Conservancy, and other organizations. He consults with homeowners and businesses to create sustainable landscapes that benefit birds, butterflies, beneficial pollinators through GO Native Landscaping.

Bookmark Gray Matters. It offers more nectar than non-native plants.