Wednesday, July 24, 2013

Monarchs arriving in the higher elevations of Arizona

Male monarch on Asclepias subverticillata - Grand Canyon
Every summer in July monarch butterflies arrive in the higher elevations of Arizona. We aren't sure where they come from or the direction of movement into the breeding grounds. On July 14th, Bob and I spotted a lone male on the South Rim of the Grand Canyon. Horsetail Milkweed, Asclepias subverticillata, is lush and in bloom all along the western section of the Rim, especially south of the rim lodging. We followed this male on Sunday morning and afternoon then again on Monday. As far we can tell at that time there was only one monarch around. Often one or several male scouts arrive first before female monarchs arrive into an area.

Male Monarch in Flagstaff
Later on the way home, we stopped at Buffalo Park in Flagstaff. A storm was brewing and bolts of lightning flashed on the nearby mountains. I ran to the milkweed patch as rain began to pelt the car and was surprised to see two males nectaring on Horsetail Milkweed, Asclepias subverticillata, still in the field. Of course it didn't take too long until they flew to shelter as did I.

Showy Milkweed, Asclepias speciosa, Flagstaff
Earlier on Saturday we had a monarch table at the Arboretum at Flagstaff. The Arboretum has huge stands of Showy Milkweed, Asclepias speciosa. Many of the flowers were beginning to senescence and seedpods should begin soon. We didn't see any monarchs or larvae here, but we did see a huge queen butterfly nectaring on still viable blooms.

Over this past weekend the first monarchs were reported in Skull Valley, Sierra Vista and Canelo. It's an exciting time to see where they appear and set up breeding grounds. It will be at least another month before monarchs  move into the lower desert. But you still have time to get ready for their arrival while you are waiting. Here are a few ways to prepare your garden:
Female monarch on Tithonia
  • Our summer monsoon rains are blessing our land with much needed rain, but if you live in an area skipped by the storms do add supplemental water to your milkweed and nectar plants. This will help spur new growth.
  • It's not too late to plant a crop of zinnias, cosmos or sunflowers. Our warm soils and rain will help them grow fast and you'll have a nectar banquet ready.
  • If you are growing Tropical Milkweed, Asclepias curassavica, they probably are not looking very good right now. Cut the stems back at least a third and lightly fertilize to spur new growth. Monarchs will find the new growth especially inviting to lay eggs on as they sweep through in early September.  Be sure to use only half the amount of recommended fertilizer in our summer heat to prevent burning. Liquid amendments are preferable to granular this time of year. Be sure to water deeply before you fertilize and again afterwards. Native milkweeds do not usually need this care.
Monarch butterfly populations are at an all time low so prepare your garden now to enjoy their presence when they sweep through. Report your monarch sightings to  Southwest Monarch Study Facebook page.