En EspaŅol
Share

Ask Mr. Smarty Plants

Mr. Smarty Plants - How to grow milkweeds (Asclepias spp.) for monarch butterflies

Ask Mr. Smarty Plants is a free service provided by the staff and volunteers at the Lady Bird Johnson Wildflower Center.

Search Smarty Plants
    
 
See a list of all Smarty Plants questions
Can't find the answer in our existing FAQs, submit a question to Mr. Smarty Plants.

Need help with plant identification, visit the plant identification page.
 
rate this answer
1 rating

Wednesday - March 31, 2010

From: Port Lavaca, TX
Region: Southwest
Topic: Butterfly Gardens, Compost and Mulch, Propagation, Transplants, Herbs/Forbs
Title: How to grow milkweeds (Asclepias spp.) for monarch butterflies
Answered by: Nan Hampton and Sean Watson

QUESTION:

I tried and tried and tried to grow Asclepias viridis, A. asperula and even A. oenotheroides from seeds and even tubers for fourteen years! Do you have advice for growing these and other milkweed plants for monarch butterflies?

ANSWER:

Mr. Smarty Plants consulted our Nursery Manager, Sean Watson, to answer this question.  Here is what he said:

"I start them in the Spring or Summer (they like heat to germinate well). The fresher the seed the better. I just sow them and cover with maybe 1/8 inch of sterile seed starting media (peat based) and keep the propagation tray in part shade. They have long tap roots, so it is better to start them in a deep propagation tray (bulb trays work great, or 5" (or deeper) cell seed starting trays). Keep the media moist until it looks like all have germinated that are going to germinate (they tend to germinate very fast/easily). It is best to not transplant them until the taproot begins to thicken (root swells and begins to harden, starts to become a true taproot). This alleviates a lot of the shock they go through when transplanting. After transplanting (we use a container mix--compost--cut with 25% sand, but can just use straight compost), I water them in immediately, and water them everyday for the next week while they are becoming established into the pot. After 1 week, allow the top 1/2 inch of soil to dry before giving them a little drink, do this for one more weeks (try to avoid flooding them at this stage--except Asclepias incarnata which is a water species and loves water, keep this species wet). Allow them to dry out 1 inch before watering during the third week. After the third week, you can start giving them a little more sun to harden them off. After a week of hardening off, place the plant in full sun and water only once the top inch of soil dries. You want to avoid watering them when they are dormant (just let the rain water them).

Another trick is to bury the seedling up to the cotyledons when you transplant. The cotyledons should rest just above the soil level, not on the soil. This will allow everything below the cotyledon to root out, thus giving your transplant an instantly longer taproot. I have had success transplanting seedlings of different Asclepias species once I see the first set of true leaves (many books suggest this). I usually transplant our seedlings directly into gallon pots to allow room for the taproot. I have had great success with Asclepias tuberosa in this way, and moderate success with Asclepias asperula. We are trying bulb trays this year and I have a feeling if we leave them in these trays longer so they can fully develop a taproot before transplanting, we may have Asclepias coming out of our ears!"

Here are a few photos from our Image Gallery of the milkweeds mentioned above:


Asclepias asperula

Asclepias incarnata

Asclepias oenotheroides

Asclepias tuberosa

Asclepias viridis

 

 

More Propagation Questions

Transplanting a young lilac
November 05, 2012 - This past spring I planted a hybrid lilac in the ground. The weather here has started to get cold, and much more so at night. Also, the temperatures go from warm to cold and back again as if unsure wh...
view the full question and answer

Varieties of Ceanothus suitable for Illinois
September 07, 2012 - Ceanothus Velutinus is the smell of western Montana, my home, to me, and I have relocated to Illinois. I miss it so much that whenever I go home I bring back a jar of ceanothis leaves and keep th...
view the full question and answer

Poppies for a wedding in August from Highlands Ranch CO
February 04, 2013 - Are poppies available to buy for weddings in August in Colorado?
view the full question and answer

Are there production timing guides for native plant production?
October 27, 2009 - We need growers timetable guide for native plants from seed to salable size. Any already published guides out there?
view the full question and answer

Aromatic sumac in Travis County
August 14, 2010 - This is an answer to article in today's, August 14, newspaper. I assume that aromatic sumac is native to Travis county because I have it all over my property. It turns bright red in the fall adding...
view the full question and answer

Smarty Plants's Facebook profile Support the Wildflower Center by Donating Online or Becoming a Member today.

Mr. Smarty Plants wants you to be his Facebook friend. Click the Facebook icon to add yourself to Mr. Smarty Plants list of friends.
E-NEWSLETTER | BECOME A MEMBER | DONATE NOW | MEDIA | SITEMAP
© 2014 Lady Bird Johnson Wildflower Center