Is It True That Milkweed Grows Back After Caterpillars?

Michigan State University scientists have found that managing common milkweed for mid-summer regrowth can increase monarch egglaying and caterpillar survival. They found that monarchs laid more eggs on the newly regrowing stems after cutting them back in June and July. However, tropical milkweed leaves stay viable all winter long, making it more likely for caterpillars to become infected. A report by the Monarch Joint Venture found that 49% of winter-breeding monarchs had OE infections, compared to only 9% of migratory monarchs sampled in Mexico and 15% of migratory monarchs.

Regrowing milkweed stems during this time is more attractive to monarchs and sometimes has quite a few eggs and caterpillars on them. If monarch eggs are laid on plants other than milkweed, the caterpillars cannot survive and ultimately starve to death. Monarch butterflies lay their eggs exclusively on milkweed plants to provide food for their young, and their caterpillars are milkweed dependent until they prepare for metamorphosis.

Cross-cutting scarlet milkweed plants results in a bushier, shorter plant with more leaves, encouraging new leaves to sprout and eventually feeding more monarch caterpillars. According to assistant professor Kirk-Ballard at LSU’s Ag Center and School of Plant, the milkweed plant will grow back quickly and recommends patience.

Monarch caterpillars are voracious eaters, having stages of growth called instars. Milkweed provides both food and shelter for a caterpillar for approximately two weeks (dependent on temperature) while it eats almost constantly. When monarch butterfly females are ready to lay the eggs that will grow into caterpillars, they look for milkweed. Some other flowers can prevent caterpillars from starving by feeding them butternut squash when they run out of milkweed.

How Long Does It Take A Milkweed Stem To Grow?

Common milkweed can regenerate new shoots within about two weeks after being cut at ground level, making it highly appealing to female monarchs, which lay two to ten times more eggs on these new stems compared to older ones. These regrowing stems are less prone to predators, allowing monarchs to thrive. Rooting milkweed cuttings takes six to ten weeks, which is ideal for fall planting so the plants establish before winter. The best time to take cuttings is mid-summer when stems are green and herbaceous. For starting seeds, begin indoors 4-8 weeks before the last frost or sow them directly in the fall or early spring.

In autumn, when milkweed seeds disperse and land on soil, they will not germinate until spring. The optimal time for planting milkweed is early spring post-frost, while seed planting is best done in late fall for natural cold stratification. Overwintering plants can be started between January and April.

Cuttings should be taken underwater, with a strong rooting hormone applied to the cut ends before placing them in moist sand, vermiculite, or potting soil. Transplanting occurs in 6-10 weeks. If leaves are eaten, cutting the plant back about two inches from the soil will encourage new growth in 3-4 weeks.

Milkweed is a perennial that typically flowers in the second or third year, and the total time from cold stratification to growth can exceed 40 days, requiring patience. Consistent watering is vital for root establishment, deep watering initially, followed by less frequent watering once established. Overall, growing milkweed from cuttings is an efficient and straightforward endeavor.

Can Milkweed Help Monarch Butterflies Recover?

Planting milkweed is crucial for the recovery of monarch butterflies and the restoration of their endangered ecosystem. Monarchs rely exclusively on milkweed for laying eggs and as a food source for their caterpillars. By creating habitats through butterfly gardens, roadsides, and prairie restorations, individuals can significantly support monarch populations. Initiatives like those from Michigan State University focus on understanding how different milkweed species affect monarch development and survival, contributing to conservation efforts.

Recent studies indicate that approximately 3. 62 billion milkweed stems are needed to reestablish monarch populations, yet only 1. 34 billion remain. Planting a variety of native milkweed species enhances the chances of caterpillars reaching adulthood. Additionally, providing nectar sources for adult butterflies and water sources, such as butterfly puddling dishes, further supports their lifecycle. Even small garden spaces can make a difference, offering essential resources for both caterpillars and adult monarchs.

While urban and suburban plantings alone haven’t solved the decline, they are a vital part of a broader strategy. Collective efforts to plant and maintain milkweed habitats are essential for ensuring the survival and thriving of monarch butterflies.

Will Milkweed Grow Back After Mowing?

Cutting back milkweed can effectively eliminate OE spores on the plants and promote new growth. Regularly re-cutting the milkweed every few weeks as it resprouts encourages healthy development. Tropical milkweed may have fewer issues in northern regions since it naturally dies back when frozen. Most milkweeds regenerate after being cut, facilitated by their strong root systems. Monarch butterflies depend on milkweed until migration in the fall, making it essential to maintain a healthy patch.

Cutting back old stalks in the fall and deadheading flowers in early summer are recommended practices. Surprisingly, research indicates that monarchs might lay more eggs on regrowth than on older milkweed stems, enhancing their chances in some instances. Although it seems counterintuitive to prune a vital plant, it can yield positive outcomes for monarchs.

In colder climates, milkweed dies back in the fall and reemerges in spring. The best growing conditions are full sun exposure for six to eight hours daily. Milkweeds are herbaceous perennials that bloom throughout summer and go dormant in fall. Periodic mowing can be beneficial, as milkweed can come back thicker and stronger than before due to its resilient root system, which outperforms grasses and clovers.

Pruning the tips can trigger additional growth, and cutting back can help attract more egg-laying monarchs. For those interested in pollinator gardens, moving milkweed from mow zones can promote better flourishing in designated areas, ensuring a steady supply for monarchs and other pollinators.

Are Milkweeds Good For Monarchs?

Access to milkweeds is essential for monarch reproduction, but additional factors are necessary to boost their numbers. These include having the appropriate plant stages and safe habitats for eggs and caterpillars to develop. Contrary to popular belief, monarchs gain both nutritional and defensive benefits from their milkweed diet (Malcolm 1991, 1995). The best choice is to plant native milkweed species, with over 100 types across North America. Common and swamp milkweeds are preferred as they support more eggs. Additionally, native milkweed benefits other native insects, enhancing overall ecosystem health.

Why Is Milkweed Illegal?

The California Department of Food and Agriculture recently banned the sale of non-native tropical milkweed, effective June 8, due to its role in the decline of monarch butterflies since the 1990s. Milkweed is vital for these butterflies, as it is their exclusive food source during the caterpillar stage. While planting milkweed is not outright illegal, regulations may vary by species and location, with some counties prohibiting non-native options in nurseries out of concern for potential harmful spores.

Historically, milkweed has been illegal in various regions due to agricultural and safety concerns, particularly about its toxicity to pets and livestock, leading to accidental poisonings if it mixes into hay. However, in recent years, many communities have shifted to support urban butterfly gardens, relaxing rules against milkweed to aid monarch conservation.

Despite its ecological importance, milkweed has developed a reputation as an invasive weed, prompting some local codes in the Midwest to threaten fines for homeowners cultivating it. In contrast, a new law in Michigan aims to protect milkweed while targeting noxious weeds.

There remains confusion as regulations may conflict between different jurisdictions, with some municipalities banning milkweed even as state policies encourage its planting to combat declining monarch populations. Experts emphasize the need to manage tropical milkweed properly, recommending cutting it back every fall to mitigate its potential negative impact on monarch migration and reproduction. Overall, while milkweed is critical for monarch survival, its management is complex due to its dual reputation as a beneficial plant and a potential pest.

Why Do Monarch Caterpillars Eat Milkweed?

Monarch caterpillars rely exclusively on milkweed plants as their sole food source throughout their development cycle, which lasts about four weeks. Unlike adult monarchs that can consume various plants, caterpillars are selective eaters, depending on milkweed for nourishment. They do not feed on tomato plants or other types of vegetation, although they may utilize these plants as shelters during their transformation into chrysalises. Research has shown that high-quality milkweed leads to better growth rates and survival for the caterpillars.

Milkweed is critical for monarchs, as it serves as their "host plant," meaning caterpillars cannot thrive without it. According to entomologist Rick Hellmich, milkweed from the Asclepias genus is vital for the monarch lifecycle. Furthermore, the leaves' cardiac glycosides, which pose risks to most animals, actually benefit monarchs; after ingestion, these toxins become part of the caterpillars’ tissues, providing them with a defense mechanism against predators.

Monarchs lay their eggs specifically on milkweed, ensuring the hatching caterpillars have access to the required food. If laid on non-milkweed plants, the caterpillars would ultimately starve. The caterpillars' unique relationship with milkweed underscores the importance of native milkweed plants for monarch survival, as well as their role in the ecosystem.

Will Dead Milkweed Come Back?

Yes, milkweed experiences dormancy in winter, dying back, but it typically regrows in spring, given favorable conditions. An exception is tropical milkweed, which doesn’t die back and requires cutting back to about 6 inches during fall and winter. In zone 5a, milkweed is often late to emerge, raising questions about its survival through winter. Remarkably, butterflies can detect individual milkweed plants from the air, landing on them to confirm their identity before laying eggs.

Milkweed should be planted in spring, as it is a perennial, preparing itself all year for winter. Edible flowers appear in late spring and early summer, with seed setting in spring and die-back occurring in fall. Deadheading, or removing wilted flowers, is a good maintenance practice. While milkweed may not grow as early as other plants in spring, it is important not to assume it's dead; its rootstock survives winter, and growth will resume when conditions are right.

Cutting back milkweed stalks should occur after flowering and seed pod maturation, ideally in late fall or winter. Generally, milkweeds are resilient: if their roots remain intact, they should re-emerge in spring. They are good at self-seeding, which is beneficial for monarch butterfly conservation. It's common for first-time growers to think milkweed is dead, as it often only shows new growth at the ground level. Typically, flowering happens in the second or third year, with subsequent seed pods developing after dispersal.

Hence, milkweed should ideally be left until evidence of fresh growth is visible, as solitary bees and insects utilize old stalks for nesting. Ultimately, milkweed ensures annual regrowth, contributing positively to local ecosystems.

Can Milkweed Regrow After Being Cut Back?

Common milkweed exhibits a remarkable ability to regrow after being cut back, making it a resilient plant ideal for gardeners aiming to support monarch populations. When a milkweed stem is trimmed near ground level, new shoots typically emerge from the roots within approximately two weeks. This regrowth not only helps control the plant's height but also encourages a denser and healthier milkweed patch.

Cutting back milkweed can paradoxically benefit monarch butterflies, as research indicates that monarchs may prefer to lay eggs on newly regrown stems rather than older ones. This increased egg-laying can lead to higher caterpillar survival rates. Additionally, cutting back the plant helps reduce the presence of predatory arthropods, creating a safer environment for monarch larvae. Maintaining a healthy milkweed patch involves regular practices such as deadheading wilted flowers in early summer and cutting back old stalks in the fall. These actions promote vigorous regrowth and ensure the plant remains a reliable food source for monarchs.

Milkweed spreads through its extensive underground rhizomes, which store energy and contain dormant buds capable of producing new shoots. While digging up rhizomes can help control milkweed spread, it is often challenging due to the plant's robust root system. Deep tilling may be necessary but is typically ineffective in completely removing all rhizomes. Therefore, managing milkweed involves cutting back stems to maintain a manageable number of plants, especially as they emerge each spring.

In cases where milkweed behaves as an annual, gardeners can cut the stems to the ground in the fall and scatter seeds to ensure new plants grow in the following spring. This method allows milkweed to persist and continue supporting monarch populations year after year. Additionally, integrating other nectar-rich plants can provide supplementary food sources for adult butterflies once they emerge. Overall, strategic cutting and regular maintenance of milkweed not only control its growth but also enhance its role in sustaining monarch butterfly life cycles.

Should I Leave Monarch Caterpillars On Milkweed?

Once larvae emerge, fresh milkweed leaves are essential, as they only consume milkweed and several species of it. If the original plant is still fresh, keeping the larvae on it for a few days is easiest. Common molting spots include under milkweed leaves, cage walls, floral tubes, and container rims, where they may remain for 24-48 hours before returning to fresh milkweed. The milkweed tussock moth, a typical species found across Eastern North America from Mexico to Canada, features an orange and black abdomen, signaling its toxicity to predators.

To care for monarch caterpillars, provide fresh milkweed daily in an enclosure. In cases of infection, it's important to remove affected caterpillars. Collecting caterpillars on milkweed leaves for indoor rearing offers added protection, but many believe it's better to leave them undisturbed. As eggs hatch, cut the leaves and place the caterpillars on new milkweed. Safety is crucial, as milkweed treated with pesticides can harm the caterpillars.

For attracting monarch butterflies, planting milkweed in gardens is vital since it serves as their nectar source and is the exclusive host plant for monarch caterpillars. Despite an army of milkweed tussock moth caterpillars on milkweed crops intended for monarchs, they can coexist, given that milkweed is the single food source for monarch caterpillars, which primarily feed on healthy, blemish-free leaves.

What To Do When Caterpillars Run Out Of Milkweed?

When monarch caterpillars deplete their milkweed supply before their final molting, it's crucial to prevent starvation by offering alternatives like butternut squash rings, which they consume to reach the last instar and form chrysalises. Monarch caterpillars rely exclusively on milkweed as their host plant. According to Kirk-Ballard, if their food runs out, gardeners can explore options: while butternut squash might not work universally, organic cucumber has proven effective.

For those in a "milkweed emergency," it’s important to consider local nurseries when there’s scarce access to milkweed from gardens or the wild. As these caterpillars crawl off milkweed to molt—a process they repeat four times—they need sufficient sustenance to transition into adulthood. Having observed numerous caterpillars transforming into large fifth instar individuals, one can imagine the panic when the milkweed runs out. While milkweed is vital for their development and provides toxic compounds that deter predators, it's reassuring to know that established milkweed plants can regrow after being consumed.

Additionally, remember to check for eggs or caterpillars periodically and rinse remaining milkweed to prolong its use. If milkweed is scarce, arranging the plants near molting areas and ensuring they are accessible can aid caterpillars in their transformation. Ultimately, while there are no true substitutes for milkweed, engaging with local resources can help nurture these vital insects.