Garden closes early Dec. 15-17 at 4 p.m. With Last Admission at 3 p.m. Due to Las Noches De Las Luminarias.

What is Great Milkweed Grow Out?

 

Great Milkweed Grow Out is an initiative at Desert Botanical Garden to grow milkweeds for monarch butterfly conservation. Monarch butterflies have declined as much as 90% over the last two decades. The good news is that you can help! In the United States, loss of milkweed habitat is a major factor in the decline of the monarchs. You can help by planting milkweed and nectar plants in your backyard.

Milkweed (genus Asclepias) is the only plant that monarch butterflies can lay their eggs on and that caterpillars can eat. Without milkweed, monarchs will not survive. Arizona has 30 species of milkweed native to the state, which means you can find the right milkweed for your backyard.

Great Milkweed Grow Out is increasing both the numbers and species of milkweed available. We are collecting seeds across the state and propagating them. We donate a percentage of our milkweeds to other non-profits and sell milkweeds to the general public through the Desert Botanical Garden’s bi-annual Plant Sale and other Garden events. We also plant pollinator gardens at 6-10 schools every year and present about monarchs and milkweed at local community centers.

What can you do for monarchs?Monarch Butterfly

You can plant a butterfly garden! Top 5 tips for planting a butterfly garden:

  1. Include host plants: Butterflies will only lay their eggs on particular plants, and it is the only food source for caterpillars. We call these hostplants. Just don’t be surprised when the plants are eaten by the caterpillars. Milkweeds are the hostplants for monarch butterflies. 
  2. Nectar (flowering) plants: Nectar plants provide food for the adult butterflies.
  3. Don’t use insecticides: Insecticides will harm the adult butterflies and their caterpillars.
  4. Don’t use herbicides: Herbicides will kill the necessary host and nectar plants.
  5. Shelter: Medium to large-sized trees provide shelter for the butterflies in inclement weather and protected places for the caterpillars to form their chrysalises.

For desert-adapted butterfly plants, check out the butterfly plant guide. Find Desert Botanical Garden grown milkweeds and other plants at the bi-annual Plant Sale.

Caring for Arizona native milkweeds

Did you buy a native milkweed from Desert Botanical Garden, and want to know how to care for it? Here are some general planting instructions:

  1. Seedlings (in a black cone) can be planted in the ground or in a larger pot. Milkweeds in a 1-gallon pot can be planted in the ground.
  2. Dig the hole only as deep as the roots but twice as wide. Set the soil aside.
  3. Carefully remove the plant from the pot, trying not to disturb the roots too much.
  4. Place the plant in the hole and carefully replace the soil you set aside around the roots. Maintain the soil line (make sure the soil is up to the same point on the plant that it was when the plant was in the pot).
  5. Gently tamp down the soil around the roots. Add more soil if needed to maintain the soil line.
  6. Lightly water the plant until the soil is saturated. Use drip irrigation or turn the hose on so the water just trickles. 
  7. Water deeply every day for about 1 week so the roots can get established. Then water every 4-5 days after that. For Asclepias angustifolia, water every 2-3 days. In the summer you can water at the same frequency but for a longer period of time during each watering.

Information on native milkweeds:

White stem milkweed (Asclepias albicans)White Stem Milkweed

  • Grows to be 8-10 feet tall and 3-4 feet wide. 
  • Makes a great screen plant once full size.
  • Can handle harsh summer heat.
  • Requires very little supplemental water once established.

Arizona milkweed (Asclepias angustifolia)Arizona Milkweed

  • Grows to be 2-3 feet tall by 2-3 feet wide.
  • Prefers some protection from the harsh summer sun.
  • This species does best on the east or north side of the house or in light shade/filtered sun.
  • This species does better with additional water.

Antelope horns milkweed (Asclepias asperula)Antelope Horns Milkweed

  • Grows to be 1-2 feet tall.
  • Can handle full sun.
  • Plant on south, east or west side.
  • This species does better with additional water.

Giant Sand milkweed (Asclepias erosa)Giant Sand Milkweed

  • Grows to be 4-6 feet tall.
  • Can handle full sun.
  • Plant on south, east or west side.
  • This species requires little water.

Desert milkweed (Asclepias subulata)Desert Milkweed

  • Grows to be 3-4 feet tall.
  • Can handle harsh summer heat.
  • Likes to be planted in full sun.
  • Requires very little supplemental water once established.
  • Great hostplant for queen butterflies.

Pineneedle milkweed (Asclepias linaria)Pineneedle Milkweed

  • Grows to be 3-4 feet tall.
  • Plant in full sun or partial shade.
  • This species does better with additional water.

 

Photo Credits:
Adam Rodriguez - Monarch butterfly
Barry Breckling - Asclepias albicans
Brent Miller - Asclepias erosa
Max Licher - Asclepias-asperula

Great Milkweed Grow Out activities are supported by the Bureau of Land Management.