How to get monarchs to lay eggs in your yard

Female monarchs lay their eggs on milkweed and on nothing else, so the way to get eggs is native milkweed, in the sun, up and green when the egg-laying monarchs are in your area, never treated with insecticide, with flowers beside it.¹² Nobody can promise a monarch will find your yard, and we won’t. What follows is everything that is in your control, with the source for each part.

1. Milkweed, because nothing else will do

The Xerces Society, writing with the USDA and Monarch Joint Venture: “Milkweeds are the required larval host plants for the monarch butterfly (Danaus plexippus).”¹ Monarch Joint Venture describes what the female does: “Monarch females usually lay a single egg on a milkweed plant, often on the bottom of a leaf near the top of the plant.”² Monarch Watch gives the reason for one egg per plant: “to ensure enough food for each larva.”³ That is why a yard needs several plants, not one.

2. The right milkweed for where you live

Plant the species that grow naturally where you are. The Xerces Society: “use seed that is sourced as locally to your property or project site as possible,” and “only plant milkweed species that are native to your area.”⁴ Monarch Joint Venture: “Plant only species of milkweed that are native to your region, whenever possible.”⁵ Monarch Watch publishes native milkweed lists by region; for the south-central states, for example, it names A. asperula, A. oenotheroides, A. tuberosa, A. verticillata, A. viridiflora and A. viridis.⁶ Tropical milkweed, the one most nurseries sell, is the one to avoid in the South and California, for reasons on its own page.⁵

3. Up when the egg-layers come

Monarchs lay eggs in different places at different times, generation by generation. Monarch Joint Venture: “Generation 1 eggs are laid from late March through April in the southern United States and northern Mexico. Generation 2 eggs are laid throughout much of eastern North America from late April through June. Generations 3 and 4 are laid throughout the northern part of the range of eastern migratory monarchs from late May through July (Generation 3) and late June through August (Generation 4).”² In Texas the first arrivals come “early each March,” “seeking emerging milkweeds,” so the milkweed there needs to be sprouting by then.⁷ West of the Rockies, monarchs “leave overwintering sites along the California coast (with a small number of sites in Baja California and Arizona) in February and March and head inland in search of milkweed on which to deposit their eggs.”⁸

The milkweed has to be up before they arrive, not planted when they arrive, which means rooted plants in the ground ahead of your window; in Texas the sources say to sow seed the previous fall, and that page explains why. And after about mid-August in the East, “most monarch butterflies … enter reproductive diapause (do not reproduce) and begin to migrate south,” so a fall garden is for feeding, not for eggs.⁸

4. Enough of it, in the sun

Monarch Watch’s guidelines for a registered monarch habitat are a sensible target for any yard. “There is no mimimum area requirement in order to certify your habitat, but Monarch Waystations function best when they are at least 100 square feet.” “Ideally, your Monarch Waystation will be located in an area that receives at least six hours of sun a day.” “We recommend that you include at least 10 milkweed plants, made up of two or more species,” though “a large number of plants (>10) of one species is also sufficient.”⁶ Plant them where you can reach every leaf, because you will be turning leaves over to look.

5. Nothing sprayed, on the plant or near it

Some nursery plants are treated with systemic insecticides, which the plant absorbs, so the leaves themselves can poison caterpillars. The Xerces Society: “It is unfortunately not possible to tell from visual inspection whether a plant contains systemic insecticides. Before buying milkweeds or other pollinator-attractive plants, we strongly recommend asking nursery or garden center staff whether the plants have been treated.”⁹ A 2024 study found that insecticides used on ornamental milkweed “can cause monarch larval mortality up to 4 wk after treatment application.”¹⁰ If you learn a milkweed was treated, Monarch Joint Venture says “the safest option is to properly dispose of the plant,” or “cover/tent plants for a year so that monarchs do not use them.”¹¹ If you can’t find out, grow from seed.

In the yard, keep every insecticide away from the bed. Texas A&M notes that even the organic caterpillar spray Bt “will also kill all the non-stinging or ‘good’ caterpillars.”¹² Aphids on milkweed are not the emergency they look like; Monarch Joint Venture: “Aphids eat the milkweed plant, not monarchs,” and their presence “is a good sign that your plant or habitat is likely free of chemicals and pesticides.” Squash them with your fingers, and “remember to check your milkweed for monarchs first.”¹³

6. Flowers beside the milkweed

Adults drink nectar, and they need it while they lay. Monarch Watch: “Plant milkweeds and nectar plants relatively close together, but not crowded, to provide shelter from predators and the elements,” and choose nectar plants “that bloom sequentially or continuously during the growing season.”⁶ Monarch Joint Venture: “Having a combination of milkweed and other flowering plants helps ensure that adult monarchs will have a food source even when the milkweed plants are not in bloom.”¹¹

What it looks like when it works

An egg is 1.2 millimeters high, under a leaf near the top of the plant, usually one to a plant, and it hatches in three to five days.² Turn the leaves over with a child; it is the kind of thing a six-year-old finds before an adult does. Then expect losses: “Less than 10% of monarch eggs reach adulthood (with some studies as low as 2%).”¹⁴ Several plants give each egg more chances, and that is not failure; it is the shape of the thing.

If nothing comes

Sometimes the plants were not up in time. Sometimes it is the year. And sometimes a monarch simply did not find you. Keep the milkweed up. Ready yards are found in some springs, and nobody can say which.

Where the city editions come in

Milkweed, sun, no insecticide and flowers beside the bed are what the national groups say for any monarch yard. The dates, the species and the tropical-milkweed rules change by region; south of Orlando, for one, Monarch Joint Venture says its tropical-milkweed advice does not apply.⁵ What changes from city to city is the dates, the freeze that decides when to plant, the species that grow on your soil, and the nurseries that stock them. That is what a city edition carries, with a source for each. The Austin edition is the first; the city finder tells you what kind of monarch place your ZIP is, and where monarchs live explains the answers.