Anyone have any emergency milkweed? The 30 or so caterpillars have totally stripped mine and the nurseries don’t seem to have any. I really don’t want to lose them. –T. Kinsey, San Antonio
I, too, have run out of food (asclepias tuberosa) for my Monarch caterpillars. I have approximately 14 caterpillars ranging from the 1st through the 5th instar. The little ones can’t eat the hard stem, which is all that is left. I am scrambling around asking everyone I know if they have any butterfly milkweed and so far, no luck. –C. Nugen, Stephenville
I have a great number of monarch caterpillars on the milkweed plants in my garden, more than I have ever seen!! Only thing is, I think there are more than there is food. Will they find nearby plants to eat or start eating the stems of the plant? Please help as I am bit worried that they will not all get to the next life stage. –L. Jarvis, San Antonio
Monarch butterflies have been arriving in the “Texas funnel” for weeks, laying their first generation of eggs on milkweeds in yards, gardens, and throughout the state. But judging from emails, text and Facebook messages I’ve been getting, we just don’t seem to have enough milkweed to keep up with their voracious appetites. The creatures eat 200x their birthweight in milkweed leaves by the time they bust their stripes to form their gold-flecked jade chrysalises.
The milkweed shortage appears to be the result of the Monarchs’ early arrival and crazy weather this year. When the Monarchs arrived in March, a lot of wild milkweed wasn’t even out of the ground yet. The wet, mild winter provoked a bountiful wildflower showing, creating serious competition from more aggressive species. Then we had a slew of 80- and 90-degree days that sped up growth of both the caterpillars and plants. Result? Lots of caterpillars and not enough food.
What to do if you find yourself with dozens of hungry caterpillars and no milkweed for them to feast on? If you don’t have access to milkweed in the wild nor from fellow gardeners, your best bet is to call local nurseries and ask if they have any Asclepias in stock. Be sure to ask for Asclepias, the scientific name, since it’s not unusual for nurseries to sell “butterfly bush” or “butterfly weed” which are great nectar plants (often in the Buddleia family) for all types of butterflies, but useless for hosting Monarchs or other milkweed feeders.
Next, tell the nursery staff that you are raising caterpillars. That means the plants you purchase for caterpillar food must be free of systematic pesticides. Nursery staff will often swear they have not sprayed anything on the plants, but that doesn’t mean the grower didn’t.
Two friends experienced this difficult lesson in the past week. Sharon Sander emailed with joyous photos of hundreds of Monarch caterpillars decimating the milkweed patch at the River Road Community Garden. Sander asked if I had any extra milkweed. Since I did not, I encouraged her to seek out pesticide-free milkweed at one of our local nurseries.
Sander located milkweed at Shades of Green Nursery in San Antonio. She explained to nursery staff that she was raising caterpillars and was told no systematic pesticides had been used. She brought the plants home and moved 200 caterpillars to the robust plants.
The next day, “They all died,” Sander wrote via text message. Sander contacted Shades of Green, an excellent nursery, and was given pesticide-free replacement plants. Still, a sad lesson.
Wendy Meyer, co-manager of Shades of Green was very apologetic about the incident and said that unbeknownst to Shades of Green, the grower had used the pesticide Dursban (chlorpyrifos) on the milkweed plants. Supposedly Dursban dissipates in 10-14 days, but in the meantime is readily absorbed into the plant tissue and anything that eats the plant.
Jenny Singleton of Grapevine relayed a similar story. Upon leaving town for vacation, she stocked up on milkweed for the hungry Monarch caterpillars she was leaving behind. “I went to my favorite nursery to buy more milkweed and left the new, full plants next to the eaten up ones,” Singleton wrote in an email. “Checked on them this AM and to my horror, I’ll bet 75% were dead! I was sick!”
Unfortunately, nurseries don’t always know their growers as well as they should. And most plant shoppers won’t buy plants with bugs on them. Milkweed plants are an ecosystem unto themselves and attract aphids, milkweed beetles, milkweed bugs, various flies and wasps. Pesticides will kill all these pests–as well as Monarch eggs and caterpillars. It’s a challenge for growers who are often inclined to spray plants immediately before shipping to make them attractive and insect free to shoppers.
If you don’t know the provenance of your host plants, the best solution is to GYO (grow your own) milkweed. Milkweed flowers develop a plump seed pod. Tropical milkweed, while not native, is easy to grow and a Monarch butterfly magnet. Remove the seeds from the milkweed fluff and sow in pots or the garden. We’ll detail that process in a future post.Like what you’re reading? Follow butterfly and native plant news at the Texas Butterfly Ranch. Sign up for email delivery in the righthand navigation bar of this page, like us on Facebook, or follow us on Twitter, @monikam.