What You Need to Know to Attract Monarchs to Your Garden

What You Need to Know to Attract Monarchs to Your Garden

WHAT YOU NEED TO KNOW to get started Attracting and Supporting
Monarch Butterflies in your Garden!

Prepared by Susie Vanderlip, Monarch Butterfly Conservation Specialist for Southern California; Monarch Watch Champ for Western Monarch Advocates; Monarch Butterfly Citizen Scientist; monarch butterfly book author and photographer (www.storyofchester.com)

Monarch Butterfly Garden (Waystation)

MILKWEED (asclepias): Plant several monarch butterfly HOST plants – Milkweed around the perimeter of the area you are planting. Monarchs love to soar across a garden, canvassing for milkweed, as opposed to having all the milkweed in one place. Males will fly back and forth over a garden with several milkweed plants ALL DAY LONG, waiting for females to arrive. Females will fly from milkweed plant to milkweed plant, flying amongst the leaves, carefully picking where they will lay each individual egg. If you see two monarchs, one chasing the other, that’s a male chasing a female. NOTE: Milkweed can easily be grown in pots as well as in the ground. If you buy a one gallon milkweed, it will grow best if repotted in a three gallon container.  IMPORTANT NOTE: Milkweed sap/oils makes monarch caterpillars toxic to birds, which won’t eat them. It also can seriously harm the human eye, so ALWAYS WASH YOUR HANDS AFTER TOUCHING MILKWEED.  DO NOT TOUCH YOUR EYES WHILE WORKING WITH MILKWEED. If you do, by accident, wash the eye out and if it starts to swell, go to the emergency room for steroids.

NECTAR PLANTS:  Plant at least 4 different types of nectar plants in your butterfly garden. Monarchs drink nectar from a variety of flowers, but they are specific so search on ‘Nectar Plants’ in this blog for a list or go to Nectar Plants for Western Monarchs | Vanderlip.com. Just a few examples include: lantana (a favorite!), coneflower, coreopsis, yarrow, zinnia, and lots of natives. You can also go to www.calscape.org to search by your zip code and see pictures of nectar plant options. Once you plant your monarch butterfly garden, you can go to www.monarchwatch.org/waystations, register your garden, and get both a certificate and a metal plaque for your garden! Lots of fun to do!

Monarch Butterfly Life Cycle

Western Monarchs have a primary breeding season of late March thru October, especially in California where the vast majority of monarchs breed. The life cycle is important to know so you can watch the process, know what to expect, and enjoy it.

Egg for 2-4 days: Females lay eggs ONLY on milkweed (asclepias) which is called their host plant. Every type of butterfly lays its eggs on their own host plant/s. Only monarch butterflies lay their eggs on milkweed, no other butterfly. And monarchs won’t lay their eggs on other butterfly’s host plants either. The female monarch lays her eggs, one at a time and by itself, on the underside of leaves. She will lay up to 500 eggs, one at time, in her 3 to 6 week life. An egg is white and about the size of the head of a pin.
NOTE: Multiple yellow dots on milkweed are aphids. They will not harm caterpillars but do suck the juice out of milkweed leaves. Best to WASH them off with the hose, do NOT use any pesticide, fungicide, herbicide, or chemicals – ever because they will kill your caterpillars.


Caterpillar/larva for 12-14 days: Yellow, white, and black banded caterpillars. They eat approx. 32 milkweed leaves over the 2 weeks they are a larva. They completely shed their skin five times over the two weeks. Each stage between sheds is called and instar, so monarch caterpillars have five instars. The caterpillar will most often crawl off the milkweed to go shed. It is vulnerable during a shed, so it leaves the milkweed to hide, shed, and return in about 2 days to eat some more. So, if you see a caterpillar off the milkweed just laying there, not moving, DO NOT TOUCH OR MOVE IT! To prepare to shed, it will have spun some silk to attach itself to wherever it is so it can crawl out of the skin. If you move it while attached, it can cause lethal damage to the caterpillar.


Chrysalis for 14 days: Full grown caterpillar (2 ½ inches long) will crawl OFF THE MILKWEED to find a place to make its chrysalis. They can crawl a few feet to many feet away, up plants and  walls. They like to make their chrysalis under things – leaves, ledges, etc – to protect themselves.  Before shedding one last time and revealing the chrysalis inside (YES, inside!), the caterpillar will again attach itself to a spot and release its feet to hang in the form of a ‘J’. It will hang that way up to 48 hours before it finally sheds and reveals the chrysalis inside. The chrysalis is a beautiful emerald green with a gold rim. It will stay green until the day before it is ready to emerge as a butterfly. At that time, the chrysalis will look black with orange – it has actually thinned and you are seeing the new butterfly inside. It must thin in order for the butterfly to crack it open and slide out. NOTE: There is a predator fly (tachinid fly) that will lay its eggs in caterpillars and chrysalids, killing them. If you see a dead caterpillar hanging upside down with a white string hanging down from the head or see a chrysalis that has a brown or black spot on it and a white string hanging down, they are both dead and a fly has laid its eggs inside. The white string is for the maggots to crawl down. Take the caterpillar or the chrysalis, put in a baggy and squish it! Yuck, but it does kill the maggots.  Point of Information: Moths spin cocoons; butterflies make a chrysalis.

Monarch Butterfly for 3 to 6 weeks (unless migrating in fall):
Coming out of the chrysalis is technically called ‘eclose’. When the monarch emerges from the chrysalis, its wings are curly and wet. If healthy, its wing veins will fill, and the wings will extend downward within 10 minutes. The monarch must hang upside down for minimum of 2 hours up to 24 hours for the wings to harden and the butterfly ready to fly off. Females are ready to mate within hours. Two butterflies chasing each other is usually a male chasing a female.



Migration and Overwintering: In early November, western monarchs migrated up to central coast California (NOT Mexico) for millions of years and overwintered (semi-hibernated) until mid-March, not eating, not mating, not flying. In November of 2020, this did not happen as usual. Less than 2,000 monarchs migrated and overwintered in California; there were 2.4 million in the 1990’s. Apparently, thousands of monarch butterflies did NOT migrate and stayed in southern California and the Bay area as resident monarchs instead. They then did NOT semi-hibernate, but instead continued breeding through the winter on tropical milkweed which has leaves year round, while native milkweed dies down to the ground by mid to late November. It is still being studied to determine if monarch butterflies will remain resident and breed through the winter using tropical milkweed or if they will return to migrating. Global warming is having an impact as the overwintering grounds in central coast California are no so warm by early February, that monarchs are waking up by mid February and looking to mate, breed and need milkweed, though native milkweed will not sprout and develop until at least late March to May. The presence of tropical milkweed is also a contributing factor as it allows for residents to have host plant for larva. It is, however, controversial because it also allows the microscopic parasite O.e. to accumulate and harm or kill caterpillars and butterflies if allowed to accumulate for over a year. THEREFORE, it is RECOMMENDED that all tropical milkweed be pruned to 6″ to 8″ stems and all the leaves removed by mid-October to kill off the O.e. and encourage monarchs to migrate if they so choose.

The California Department of Fish and Wildlife is involved in the conservation plan for our western (California) monarch migration and save the monarch population. As a result, it has a Ruling that says we are not to touch a monarch egg, caterpillar, chrysalis, or butterfly; and we are not to rear them. This means that they do NOT want us to put them in habitats or take eggs inside to rear. It is also highly discouraged to raise 100’s of monarchs by collecting eggs and caterpillars. The weaker monarchs are naturally weeded out by nature. We humans want to save them all and may well be weakening the population by saving as many as we can. PLEASE stay informed as research comes out over the next two years.

Reputable Resources:

JOIN my Facebook group:  ‘Monarch Butterfly Guardians (southern California)’ to stay informed, ask questions, learn more!
Follow my Facebook page:  ‘Monarch Butterfly Speaker