Butterfly · Rearing log

Raising monarchs

Danaus plexippus · host plant: milkweed, Asclepias

Every summer I raise monarchs in my backyard garden, from tiny eggs on the milkweed to the day they fly off. Here's how, stage by stage.

Egg: About 4 days
Caterpillar: About 2 weeks, 5 instars
Chrysalis: 8 to 15 days
Butterfly: 2 to 5 weeks; fall migrants up to 9 months

By the numbers

My 2026 season

From my check-in texts and the kitchen whiteboard. Butterflies on the bottom, then chrysalises, then caterpillars on top. Together they add up to the total: 73 on Aug 25, and all 100 by mid-September.

2026 at a glance

100Raised

98Released

2Still in chrysalis

As of October 21.

Butterflies, chrysalises, and caterpillars, 2026

Caterpillars
Chrysalises
Butterflies

Show the numbers as a table

Date	Butterflies	Chrysalises	Caterpillars	Total	Notes
Aug 25	10	34	29	73	Board photo, date to check. Caterpillars include 4 eggs
Sep 5	36	39	19	94	30 released + 6 butterflies not yet out
Sep 8	47	—	—	—	Butterfly count only
Sep 9	52	—	—	—	Butterfly count only
Sep 14	69	—	—	100	31 in care: 14 chrysalises, 8 caterpillars, 9 in small
Sep 27	77	19	4	100	Board photo
Sep 29	90	9	1	100	Board photo
Oct 1	94	6	0	100	Board photo
Oct 13	96	4	0	100	Check-in
Oct 20	97	3	0	100	1 released
Oct 21	98	2	0	100	1 released

Monarchs by stage, 2026

Eggs
Caterpillars
Chrysalises
Butterflies

Show as a table

Day	Eggs	Caterpillars	Chrysalises	Butterflies	Total
Aug 25	4	25	34	10	73
Late Aug	0	29	40	20	89
Sep 5	0	19	39	36	94
Sep 27	0	4	19	77	100
Sep 29	0	1	9	90	100
Oct 1	0	0	6	94	100
Oct 13	0	0	4	96	100
Oct 20	0	0	3	97	100
Oct 21	0	0	2	98	100

Method

How I raise them

This is strictly business. The monarchs are not pets. Their numbers have dropped enough that the U.S. Fish and Wildlife Service has proposed listing them as threatened.³ The goal is to get more of them to adulthood, with as little impact as possible.

Find the eggs. Most come from common milkweed, Asclepias syriaca. Some come from swamp milkweed, Asclepias incarnata.
Hold them until they hatch. Eggs go into small containers lined with a moist paper towel.
Feed fresh milkweed. Once a caterpillar hatches and starts eating, it gets fresh milkweed.
Start in the nursery. Eggs and the smallest caterpillars stay inside.
Move outside. Bigger caterpillars go to enclosures outside, where they form their chrysalises. The number of enclosures changes with how many monarchs there are.

Haley smiling in the garden with her black curly-haired dog on her lap and a spaniel at her feet, next to the potting table — Wes and Colt are the pets. The monarchs are not.

Stage 1 · About 4 days

Eggs

A female monarch lays her eggs one at a time, usually on the underside of a milkweed leaf.¹ Each egg is about the size of a pinhead, cream colored with fine ridges.

The caterpillar hatches in about four days, and its first meal is its own eggshell.¹

Stage 2 · About 2 weeks

Caterpillars & molting

For about two weeks the caterpillar does almost nothing but eat milkweed. It grows so fast that it outgrows its skin four times. Each growth stage between molts is called an instar, and there are five.¹

It's like pulling off a pair of tight pants.

A molting caterpillar wriggles forward and walks right out of its old skin.

It goes still. Before a molt the caterpillar stops eating and rests, often off the milkweed.²
The old head comes off. The old head capsule is shed, and the caterpillar crawls out of the rest of its skin.²
It eats the skin. The shed skin is usually eaten to recycle its nutrients.²

Molting · my video

1st instar2–6 mmPale and almost see-through, with a black head
2nd instar6–9 mmBlack, white, and yellow bands start to show
3rd instar10–14 mmBands are bold, front tentacles grow longer
4th instar13–25 mmWhite spots on the prolegs
5th instar25–45 mmThe biggest eater, then it wanders off to pupate

Sizes from Monarch Joint Venture.¹

Try it

Find the caterpillars

These are early instars, a few days old, on cut milkweed leaves. There are four. Tap each one you spot.

Found 0 of 4

Hint: the black specks are frass. That's caterpillar poop, and it means someone's been eating.

Four tiny early-instar monarch caterpillars on cut milkweed leaves on a paper towel

Stage 3 · 8 to 15 days

The J-hang and the chrysalis

When a fifth instar caterpillar is ready, it spins a small silk pad, grips it with its back end and hangs upside down in the shape of a J.²

Then comes the last molt. The skin splits and slides up, and underneath is the green chrysalis with its gold dots. Monarchs make a chrysalis, not a cocoon.

The butterfly emerges 8 to 15 days later.¹

Dozens of green monarch chrysalises pinned along a white folding station, with one newly emerged butterfly — The chrysalis station at its fullest.

Stage 4 · Emerging

Out of the chrysalis

The butterfly splits the chrysalis open and climbs out with small, crumpled wings and a swollen body. It hangs from the empty shell and pumps fluid into its wings until they reach full size.

It stays hanging for a few hours while the wings dry and harden. Only then can it fly.

Several newly emerged monarchs hanging from empty clear chrysalis shells inside a white box, drying their wings — Drying their wings on the empty shells.

Stage 5 · Release day

Letting them go

A monarch perched on Haley's finger above the garden path — Ready to go, off my finger.

A monarch with open wings on a pink coneflower in the garden — First stop: the coneflowers.

Male or female?

Males have a small black spot on a vein of each hindwing. Females have no spot and thicker black veins.¹

Your turn

Help monarchs

Plant milkweed

It's the only plant monarch caterpillars eat. Choose a kind native to your area.¹

Add nectar flowers

Butterflies need flowers to feed on, like the coneflowers in these photos.

Skip the spray

Insecticides kill caterpillars too, even a little drift onto milkweed.

Sources