The plight of monarch butterflies is well-known. The inhabitants of the monarch’s host plant, native milkweed, is diminishing, which makes it troublesome for the butterflies to outlive. Because of this, many gardeners have been planting milkweed to attempt to assist the monarchs. However one sort of milkweed that has been marketed as being good for monarchs – tropical milkweed – is in actual fact an issue for these butterflies.
Earlier than you begin planting tropical milkweed seedlings, it is advisable perceive the methods by which this plant upsets the migration of the species.
What’s the Distinction between Tropical and Common Milkweed?
Not each milkweed species is strictly the identical. Tropical milkweed versus native milkweed – precisely what are the variations?
Tropical milkweed (Asclepias curassavica) is a horny plant, with blossoms and lovely inexperienced foliage. In delicate climates, tropical milkweed doesn’t go dormant. It thrives in spring, summer time, fall and winter.
Native milkweed crops, however, die again after they bloom. Additionally they have flowers and plush leaves, however as soon as winter arrives, they go dormant. This distinction proves crucial after we contemplate the connection of the crops to the butterflies.
The Advantages of Rising Tropical Milkweed in Your Backyard
Tropical milkweed is just not solely a horny plant, however it’s so simple to develop. Evaluate this to native milkweed which is troublesome to propagate. It requires chilly stratification of seeds and doesn’t consistently germinate. The tropical selection has spectacular blossoms that decoration the backyard from June by means of November, placing on a superb show. Tropical milkweed plant care is minimal, and, in hotter areas, it both thrives all 12 months lengthy or returns yearly as a perennial.
With all of those advantages, the tropical milkweed plant makes an excellent impression on gardeners who wish to help the monarch. You could marvel why it is best to plant the tougher native milkweed when this tropical selection is each prettier and simpler to deal with. Right here’s why.
Why Tropical Milkweed is Unhealthy for Monarch Butterflies
However regardless of all this, tropical milkweed is unhealthy for the monarch inhabitants. It interferes with monarch migration and replica in a number of methods.
First, within the north, tropical milkweed grows on the similar time of the 12 months as native milkweed. This may confuse the butterflies and make them consider that it’s breeding time quite than migration time. For instance, in Minnesota, the presence of tropical milkweed prevents monarchs from beginning on their regular fall migration to Mexico. Whereas it takes a number of generations of monarchs to fly north from Mexico, these butterflies fly all the best way again to Mexico in a single era. As a result of this flight requires a lot power, the adults cross into reproductive diapause, that means that they don’t mate. But when the monarchs encounter tropical milkweed, they will get away of their diapause, lay eggs, and keep within the space. When a chilly snap comes, the butterflies, caterpillars and eggs will die.
One other drawback happens in delicate climate areas the place tropical milkweed survives the winters. Monarchs that go to the crops deposit a protozoan parasite referred to as Ophryocystis elektroscirrha (“OE”) on the milkweed leaves. Monarch caterpillars hatching out on the plant eat the leaves along with the OE. Over time, the degrees of OE grow to be poisonous, which isn’t true for native milkweed. Though monarchs deposit OE on native milkweed as effectively, the plant at all times dies again after flowering, killing off the OE yearly. As local weather change continues to heat the plant, tropical milkweed might efficiently overwinter in increasingly more areas, enlarging the scope of the OE situation.
Is it Doable to Develop Tropical Milkweed Safely?
There could also be secure methods to develop tropical milkweed. This plant may be safely grown in colder-winter areas, since it would die again with the primary frost. In hotter areas, gardeners would possibly strive rising it in greenhouses. However because the world local weather continues to heat, the higher, safer possibility is solely to not plant it and plant native species as a substitute.
Wildlife-Pleasant Alternate options to Tropical Milkweed
In the event you love the look of tropical milkweed however have been satisfied to not plant it, don’t fear, there are wildlife-friendly alternate options. If you’d like a local species that’s drought-tolerant, strive yarrow (Achillea millifolium). It has pretty yellow, pink, pink, or white blossoms. The Zinnia (Zinnia elegans) is an alternative choice. It’s an annual and there are numerous cultivars in several colours. Another choice is tickseed (Coreopsis), a local perennial with gold and pink flowers.
Often Requested Questions
Is tropical milkweed invasive?
Sure, tropical milkweed is invasive. It escapes cultivation and establishes within the wild.
Is tropical milkweed a perennial?
Tropical milkweed is a perennial plant in USDA zones 8 – 11, rising as an evergreen in lots of heat areas. It’s an annual in colder zones.
