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First Generation Monarchs 2019 Are Arriving

First Generation 2019 Monarch Caterpillar


The garden needs some tender loving care.  I'm going back down there this afternoon to replace some of the straw that has washed away by our latest deluge of rain. Yesterday we discovered three monarch caterpillars in one of our three common milkweed patches.  I rescued one of them shown in the photo above.

The Story of Milkweed and Monarchs

It's a well known fact that Monarch butterflies (Danaus plexippus) will only deposit their eggs on a milkweed (Asclepias) plant and that Monarch caterpillars will only feed on milkweed leaves.  But guess what?  There are over 100 species of milkweed plants in North America and over 30 of them are native to Texas. 

Native Plant Enthusiasts recommend against tropical milkweed 

According to some, not all milkweed is created equal.  Many native plant enthusiasts are against tropical milkweed, a native to Mexico.  One of their main objections is that the tropical milkweed lasts until the first freeze and in some zones will last through the winter.  This entices monarchs to overwinter in Texas and Florida when they should be going on to the highlands of Mexico for the winter. 

However native milkweed at the Garland Community Garden was all dried up by the first of August last year--about two weeks prior to their first arrivals around mid August.  It takes five generations of monarchs to complete the cycle to get them to migrate to Mexico in the fall.  The fifth generation is the one that is genetically programmed to fly to Mexico and semi- hibernate for about six months and then start the new first generation the following spring.  The first four generations are genetically programmed to die 2 to 6 weeks after they eclose.  In Texas and Oklahoma we need to especially make sure there is milkweed--in the spring for the Monarchs to deposit the eggs of the  first generation and then again in the fall for them to deposit the eggs for the last generation of the year.

Thus many of the monarchs arriving in North Texas  beginning in mid August through September are the fourth generation who are looking for milkweed to deposit their eggs for the fifth generation. If it were not for the tropical milkweed we also had at the garden, there would have been no milkweed for the monarchs. Thus I still intend to plant tropical milkweed in the garden this year. Of course I will cut it down at the end of the first week in October.  I don't want any fifth generation Monarchs hanging around.

I don't know why, but our native milkweed was all gone just before the Monarchs began returning in mid August last year. Perhaps it is the species.

It might be because our stand of common milkweed was only two years old.  I'll watch it closely this year.  If the native milkweed lasts until the end of September, then I'll recommend to the club that we stop planting tropical milkweed.  If not we will plant tropical milkweed again next spring as we will not leave the monarchs to fend for themselves.  Our mission is to support monarchs.  This fall we will also plant seeds of other species of native milkweed.  Native is of course always preferable; however, some food is better than no food.

We Might Remember that Our Native Plants Are Evolving Too

Like people and critters plants also evolve/adapt to survive the onslaughts of urbanization with its herbicides and pesticides.  Who's to say what's happened to our native milkweed and its survival strategies?  Honestly, I don't think people know but perhaps there are some studies on that somewhere.

From my own personal field observations, all our native milkweed was gone by August 1 and the fourth generation Monarchs visiting the Garland Community Garden in late August through September of last year would have been SOL if it were not for tropical milkweed.

Asclepias syriaca often called common milkweed, is another species that grow well all over Texas.  This is the variety that we have growing at the Garland Community Garden.  Currently we have 250 Asclepias Syriaca in three different plots.  This is their third year.

Milkweed in the Medicine Wheel at the Garland Community Garden.  Native Americans  used this plant for various medicinal purposes.

Asclepias syriaca flower buds - Garland Community Garden

Friday, May 3, 2019