Actual size and flowering may vary slightly based on season.
Desert Milkweed
Desert Milkweed is an Arizona native that forms an upright clump of slender gray-green stems. Monarch and queen butterflies lay their eggs on it, and their caterpillars feed on it. Pale yellow flower clusters top the stems from spring into fall, followed by horn-shaped seed pods. It takes full sun and reflected heat on very little water.
Best for: butterfly gardens, an upright accent near a pool, hot spots with reflected heat, and native desert beds on very little water.
Monarch and queen caterpillars feed on it, and adult butterflies drink from the flowers. Plant a small group about 3 feet apart so the caterpillars have plenty to eat. Leave the chewed stems alone, since the plant grows back.
The clump of slender, upright stems makes a clean vertical accent about 3 to 5 feet tall. It drops very little debris, so it is a common pick for planting around pools. Keep it where pets will not chew it.
It takes full sun and reflected heat, so it can go beside a hot wall or driveway. Once rooted, water it about once a month at most. Rocky, dry soil is fine as long as it drains.
Soil that stays wet can rot the roots, so plant it where water drains away. Too much water or too little sun makes it leggy, and lush growth draws aphids. It is toxic to pets if eaten, and the milky sap irritates skin.
- Butterfly group3 ft apart
- Looser planting4 ft apart
For the first two weeks, water a new plant every 1 to 2 days in summer, or every 3 to 4 days in cooler months. Then stretch the time between waterings. Once rooted, water about once a month at most. Too much water makes it leggy, draws aphids and can rot the roots.
Aphids are common but rarely do real harm, and other insects feed on them. Watering less often also helps.
It needs very little pruning. Every 3 to 5 years, cut it to the base in late fall or winter, and it comes back with fresh growth. It does not need any fertilizer.
The milky sap irritates skin and eyes.
Drainage test first. Dig the hole and fill it with water. If water is still sitting in the hole a day later, you likely hit caliche, clay or hard soil, so fix the drainage before planting. If it drains very fast, the soil is sandy. Standing water around roots is a common reason new plants fail.
Weed cloth. Cut it away from the planting hole and where the roots will spread. Remove any plastic sheeting completely, since it keeps water and air out of the soil.
Rock or decomposed granite with no soil underneath. Bring in soil close in texture to your native soil, mix it with the soil below, and build up enough depth for roots before planting.
If you can break through. Use a breaker bar, pick, or jackhammer. Dig through the caliche and break out the solid chunks. Backfill with the soil you dug out, with no compost or manure in the hole. Confirm drainage before planting.
If you cannot break through. Dig narrow holes through the hard layer beside the root ball, not under it, and refill them with the same soil, not gravel. If it still will not drain, plant on a low mound of the same soil.
Root ball. Check the outside edges for any roots circling around. Loosen or cut those so they grow outward. Do not break up the center of the root ball.
Depth. The top of the root ball should sit at or just slightly above the surrounding soil level. Planting too deep can lead to rot and kill the plant.
Drip emitters. At planting, put the emitters on the root ball, on different sides of the plant. After about 2 months, move them to the outer edge of the root ball. Over the first year, add emitters farther out toward the edge of the branches as roots grow. Once a plant is rooted, never water only at the trunk.
Is Desert Milkweed a host plant for monarch butterflies?
Yes. Monarch and queen butterflies lay eggs on it, and their caterpillars feed on it. Adult butterflies also drink from the flowers.
Is Desert Milkweed native to Arizona?
Yes. It grows wild in dry washes and on rocky slopes below about 3,000 feet in Arizona, California, Nevada and northwest Mexico.
How big does Desert Milkweed get?
About 3 to 5 feet tall and 2 to 4 feet wide. It forms an upright clump of slender stems from a woody base, and it grows at a moderate pace.
How far apart should I plant Desert Milkweed?
Plant about 3 feet apart for a butterfly group, or up to 4 feet apart for a looser planting. The Spacing tab shows both.
How often do you water Desert Milkweed?
Once it is rooted, about once a month at most. It handles long dry spells. Too much water makes it leggy, draws aphids and can rot the roots.
Why does Desert Milkweed have no leaves?
That is how it grows. It puts out small leaves on new growth, but they drop quickly, so the gray-green stems do the work. It does not mean the plant needs more water.
When does Desert Milkweed bloom?
On and off from spring into fall, with pale yellow flower clusters at the stem tips. Horn-shaped pods about 3 inches long follow, then split to release fluffy seeds.
What are the aphids on my milkweed?
Aphids are common on milkweed and rarely do serious harm. Leave them for ladybugs and other insects that feed on them, and water less often so the plant is less inviting to them.
Is Desert Milkweed toxic to pets?
Yes. Milkweeds are toxic to dogs, cats and horses if eaten, so plant it where pets will not chew it. The milky sap can also irritate skin and eyes, so wear gloves and wash your hands after pruning.
How do you prune Desert Milkweed?
It needs very little pruning. Every 3 to 5 years, cut overgrown clumps back to the base in late fall or winter. It comes back with fresh stems.
Does Desert Milkweed need fertilizer?
No. Skip fertilizer, since it tends to cut down on flowering.
Is Desert Milkweed good by a pool?
It is a common pick for planting around pools. It drops very little litter, and it takes full sun and reflected heat.
Desert Milkweed for sale in Arizona, delivered to you
Desert Milkweed is an Arizona native and a host plant for monarch and queen butterflies. It forms an upright clump of gray-green stems topped with pale yellow flowers from spring into fall. Below is what to expect in a Valley yard, from size and spacing to water, aphids and pruning.
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Desert Milkweed for monarch and queen butterflies
Desert Milkweed is a host plant for monarch and queen butterflies. The butterflies lay eggs on it, and the caterpillars feed on it. Adult butterflies drink from the flowers too.
How big does Desert Milkweed get?
Plan on about 3 to 5 feet tall and 2 to 4 feet wide. It forms an upright clump of slender gray-green stems from a woody base. Small leaves appear on new growth and drop quickly.
How often do you water Desert Milkweed in Phoenix?
Once it is rooted, water about once a month at most. It handles long dry spells. Too much water makes it leggy and draws aphids.
Does Desert Milkweed take full sun and reflected heat?
Yes. It takes full sun and reflected heat, and it is hardy to about 20°F. Plant it in soil that drains well, since wet soil can rot the roots.
When does Desert Milkweed bloom?
Pale yellow flower clusters open on the stem tips on and off from spring into fall. Horn-shaped pods about 3 inches long follow and split to release fluffy seeds.
Aphids on Desert Milkweed
Aphids are common on milkweed and rarely do serious harm. Ladybugs and other insects feed on them. Less water makes the plant less inviting to them.
How do you prune Desert Milkweed?
It needs very little pruning. Every 3 to 5 years, cut overgrown clumps back to the base in late fall or winter. It comes back with fresh stems.
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