While many butterflies require certain host plants to grow their young (a list of other butterfly host plants may be found here), no butterfly is more important to our collective psyche than the monarch butterfly. Monarch butterfly numbers have plummeted in recent decades, and an increasing number of home gardeners want to help by planting a monarch butterfly host plant in their yard.
Monarch butterflies evolved with milkweeds, and as a result, their caterpillars developed a unique adaption that allows them to feed on a plant that few other insects can. Cardenolides are poisonous chemicals found in the latex-based sap produced by milkweed plants. With the exception of a few species, most other insects are unable to metabolize these toxins, which either kills them or causes them to avoid them altogether owing to their unpleasant taste. However, monarch caterpillars absorb these toxins while feeding on milkweed leaves, making the caterpillars themselves poisonous to predators. The poisons contained in the monarch butterfly host plant actually aid to protect the caterpillars and adult butterflies against predators such as birds and other insects.
Here’s a video of Jessica Walliser finding little monarch caterpillars on milkweed in her own backyard.
Asclepias tuberosa
All monarchs are invited! Butterfly Weed will help our lovely native monarch butterflies thrive. Milkweed is the only plant that monarch caterpillars will consume, thus if you actually want to help the monarchs, this is the perennial you should plant. Butterfly Weed grows naturally in ordinary to dry soil from the Rocky Mountains to the East Coast. Female monarch butterflies that have traveled to Mexico will migrate north in the spring, following Butterfly Weed and other Milkweeds as they emerge from dormancy. Their goal will be finished when they lay their eggs and die.
Can monarch caterpillars survive on butterfly weed?
Because the butterfly weed has a big taproot that can reach a depth of a foot or more in the soil, division is difficult, but it can be done in the fall or early spring before new growth begins. Butterfly weed necessitates the identification of the optimal plant location. Plants grow more stems as they mature, and they don’t transplant well. Because of its previous therapeutic usage in treating lung inflammation, the taproot is also known as pleurisy root.
After fertilization, butterfly weed forms a seed pod. The seed pods, also known as follicles, are three to six inches long and turn brown and split, causing the seeds to be dispersed in the wind by their silky-tails. The seed pods can also be clipped to encourage more flowering and keep the plants from self-seeding. In dried flower arrangements, the seed pods are appealing.
It’s difficult to talk about butterfly cannabis without mentioning its main consumer. This notable perennial is important as a monarch caterpillar host plant. Female monarch butterflies that lay eggs favor the newer growth of the butterfly weed plant and produce roughly 700 eggs over a two- to five-week period. The egg stage lasts three to eight days, depending on temperature. Caterpillars, also known as larvae, hatch from the eggs and become ravenous diners of butterfly weed and other Asclepias genus milkweeds.
The monarch caterpillars are easily identified by their yellow, white, and black stripes. The caterpillars molt throughout this nine to fourteen-day period when they outgrow their skin. Instars are the intervals between molts.
The monarch caterpillars eat cardiac glycosides, which are toxins found in butterfly weed (and other milkweeds). This toxin is more concentrated in the caterpillar than in the plant’s leaves, and it persists through the next two phases of metamorphosis. Predators have learned to avoid them due to their brilliant warning colors and toxicity, as well as the fact that birds and other animals who eat them become sick and vomit.
The next step of metamorphism is triggered by hormones produced by the caterpillar, and the pupa stage is commonly known to as a chrysalis. Caterpillars aren’t always able to pupate on the butterfly weed. They can go up to 20 feet away from the garden in search of a suitable pupation site. The caterpillar hangs upside down after molting for the last time, and silk is generated from a spinneret at the bottom of its head. Under typical settings, this stage lasts eight to fifteen days after encasing, after which the change is complete. The black, orange, and white wing patterns become evident through the chrysalis just before the butterfly emerges.
Last year, after renovating a raised flower garden at the side of my house to contain butterfly weed, I discovered my first ever chrysalis.
The caterpillar had moved about 10 feet from the side flower bed to a column on my front porch to pupate. The wing patterns were apparent by the time I noticed it, and the chrysalis was gone in a matter of days. I’ve since discovered that they can pupate on just about anything and then live for another two to six weeks after emerging as adults. Monarch butterflies that travel south spend the winter for six to nine months.
What is eating my butterfly weed?
Milkweed leaves have been known to be eaten by deer and rabbits, and milkweed bugs, tussock moths, queen butterfly larvae, and other insects feed on the plant.
Do monarch caterpillars eat all types of milkweed?
Monarch caterpillars solely eat the leaves of milkweed, which is the only plant that this renowned butterfly species feeds on. As a result, milkweed is essential for monarch butterfly survival. They won’t be able to finish their life cycle without it, and their populations will dwindle.
Indeed, milkweed destruction in agricultural areas, as well as urban and suburban environments, is one of the key reasons monarch butterflies are in trouble today.
Plant Milkweed
The good news is that planting milkweed is one of the most straightforward ways that everyone of us can help monarch butterflies. There are many dozen species of this wildflower native to North America, therefore no matter where you reside, you will find at least one milkweed species.
It’s always better to plant milkweed species native to your area. To add to your garden or any landscape in your town, you can harvest your own seed or purchase seed or plants. Three species, common milkweed (Asclepias syriaca), swamp milkweed (A. incarnata), and butterflyweed (Asclepias syriaca), have particularly extensive ranges and are good choices in most regions (A. tuberosa). The latter two are exceedingly decorative and generally available through the nursery trade.
Tropical milkweed, which may be found in many retail nurseries, is not native to the United States. It has, however, become naturalized in the Southeastern United States. Its long bloom time is being discovered to have certain negative consequences on monarch migration and to be a source of disease propagation among monarch populations, according to science. If you have tropical milkweed in your yard, it’s a good idea to prune it down in the winter to help monarch butterflies to migrate to their natural wintering grounds.
What if monarch caterpillars run out of milkweed?
When it comes to pesticides, the most damaging poison to feed to hungry Monarch caterpillars is likely to be found on Certified Organic veggies. BEFORE CUTTING THE VEGETABLES, WASH THEM. Rinse the veggie and your hands thoroughly. Bt (Bacillus thuringiensis) is a bacteria that lives in the soil and kills caterpillars. It’s used by organic gardeners specifically to kill caterpillars. The knife blade might transmit Bt bacteria into the flesh of the vegetable when you peel it.
Butternut squash has been the most popular alternative for milkweed leaves among aficionados. Cucumber, zucchini, and pumpkin are some of the other vegetables that have been successfully fed to Monarch caterpillars in the last instar (the last few days).
Caterpillar frass (excrement) turns the color of the vegetable a day or two after consuming it. Frass will fall to the soil when the cubed vegetable is speared on a stem above the soil, keeping the vegetable clean and drier than if it is laying on the soil or on the bottom of a rearing container.
Less mold and mildew means a cleaner and dryer environment. Mold and mildew can quickly cause disease and death. Vegetables mold and mildew far more quickly than milkweed leaves, which is why keeping vegetable chunks off the rearing container’s floor is better for caterpillars.
Will butterfly weed bloom the first year?
Milkweed, also known as asclepias, is native to North America, and one of them, Asclepias tuberosa, has been named Perennial Plant of the Year by the Perennial Plant Association this year. This plant, sometimes known as butterfly weed or butterfly milkweed, has bright orange flowers that attract a variety of butterflies and bees with nectar and pollen. Butterfly weed’s leaf isn’t a favorite meal of monarch caterpillars, but it can help them survive. This drought-tolerant plant prefers a dry, sunny environment and is hardy in Zones 3 to 9.
Upright stems with clusters of bright orange flowers contrast attractively with the shiny green leaves of butterfly weed. Unlike other members of the genus, the stem sap is not milky. This milkweed is not invasive since it does not spread by runners like common milkweed (Asclepias syriaca). Although deer are not attracted to butterfly weed, aphids can be an issue in gardens and greenhouses.
This plant is expected to be in great demand in the next years. Butterfly weed blooms readily the first year after seeding, but there are a few crucial elements to remember if you want to grow it professionally.
This species displays some of the most extreme photoperiod reactions we’ve ever seen. It’s an obligatory long-day plant, which means it has to flower during long days. When grown at an average of 68° F, plants develop quickly under photoperiods of 14 hours or more, and begin flowering about eight to nine weeks after transplant. Plants that are exposed to photoperiods of 12 hours or less, on the other hand, die dormant after a few days (Figure 1, pictured above). Leaves droop, shoot growth appears to stop, and existing flower buds may suffocate (Figure 2). Unfortunately, simply reverting to longer days will not return the plants to active growth. A nine-week or longer cold treatment is required to break this dormancy; in our testing, all dormant plants treated to 41° F for 15 weeks bloomed.
It is critical to provide long days to plants in order to keep them actively growing. We propose at least 16 hours of daylight or four hours of night disruption illumination. A minimum intensity of 2 molm2s1 should be delivered by photoperiodic illumination. Use incandescent lights or LED bulbs intended to control blooming that emit both red and far-red radiation. Maintain these extended photoperiods for plants until natural daylengths reach at least 14 hours.
Butterfly weed has a huge tap root, making transplanting or dividing established plants difficult. It’s critical to utilize a well-drained medium in container production, so consider adding more perlite to a standard peat+perlite mix. During production and cold treatments, be careful not to over-water. The taproot attracts fungus gnat larvae, so keep an eye on the roots if your plants aren’t doing well.
Butterfly weed can grow up to 3 feet tall in the wild, but in container production, our plants were only 12 to 18 inches tall when they first bloomed. Sprays of daminozide (e.g., B-Nine, Dazide), paclobutrazol (e.g., Piccolo, Bonzi), and uniconazole (e.g., Piccolo, Bonzi) are apparently helpful for height management (e.g., Sumagic, Concise). To help fill out containers, use many plugs per pot or squeeze seedlings soon after transplant.
Will my milkweed grow back after caterpillars?
This week, a question came into Ask Gardenerd that I had asked myself last year:
“This is my first year planting swamp milkweed for monarch butterflies, and I’ve already seen two butterflies emerge from their cocoons this morning.” This year, I had five plants; next year, I’m going big. Question: There is a lot of information on how to get plants started, but none on how to maintain them at the end of the season. Should we prune the stems of the existing plants or leave them alone? Now that winter is approaching, I’m not sure what to do. “Thank you, Bob”
You’re right, Bob, not many websites discuss what to do with milkweed once the season is through. Last year, I came across the problem while staring at an 8-foot stem of Asclepias Physocarpa that had been stripped of its leaves following a season of successful Monarch residence. So, what’s next? The answer is that it is debatable.
If the milkweed you’re growing, like the Asclepias Physocarpa depicted above, performs as an annual in your hardiness zone, you can spread the open seed pods about the soil and trim the stalks down to the ground. The roots will disintegrate over time, and new plants will emerge from the seeds that have been disseminated.
This milkweed was supposed to be a perennial in my garden, but I opted to cut it down after waiting several months for fresh growth (while other milkweeds sprouted new leaves).
Just in case it chose to leaf out again, I left around 6 of stem above ground, but it didn’t. Instead, seeds I distributed nearby sprouted into new sprouts.
You indicated that you’re growing Asclepias incarnata, or swamp milkweed. Although it is technically a perennial, if you have problems like I had (no leaves sprouting), re-seed and prune down old foliage.
If the milkweed is a perennial, such as Asclepias curassavica (tropical milkweed), you’ll find little leaves emerging from the plant’s base after the upper stems have been destroyed. Hold your breath for that. Then trim the stems back to the new growth, and the plant will take off.
As a reminder, if at all feasible, cultivate milkweeds that are native to your state. We have numerous native milkweeds in California, and seeds for at least one of them can be bought via Theodore Payne Foundation.
Does butterfly weed spread?
Butterfly weed, like other forms of milkweed, contains enormous seed pods that distribute little seeds by wind-blown hairs. As a result, unless the seed pods are broken off before they mature and split, it can become an invasive plant that spreads everywhere.
How do you protect caterpillars from milkweed?
Place 5 Gallon Paint Strainers or Mosquito Netting over your milkweed to keep wasps away. To provide additional support, tomato cages can be used. This will prevent them from stealing your helpless caterpillars. This method works best with milkweed plants in pots.