Saturday, February 26, 2011

The Monarch Spring Migration

Desert Botanical Garden 3/6/09
Dr. Chip Taylor, Director of Monarch Watch, posted an important reminder this week: Monarch butterflies in Mexico are on the move! Monarchs begin mating around Valentine's Day and a few begin to leave their winter haven slowly in the following weeks. First monarch sightings in Texas are usually reported by the end of the first week of March. What about Phoenix? Last year we spotted a weathered female monarch laying eggs at the Desert Botanical Garden on March 15th. In 2009 we found four monarch larvae in the Herb Garden on March 6 - overwintering monarchs mated in mid-February.

Tatsuyo, South Mountain, 2-24-11
Monarch presence and absence are not well understood in the Phoenix area. Observations vary from year to year. Our warm Fall and early Winter encouraged more monarchs to lay eggs through December. Three freezes, two of them hard freezes, decimated monarch populations at the Desert Botanical Garden and Tempe Marsh. But a few monarchs survived at Rio Salado and on South Mountain in Tatsuyo's yard. So far in February ten monarchs eclosed at her house - these two females were released on their way on Thursday. There are possibly others in hidden niches around town, too.

The occasional rare hard freezes and the last (hopefully) cold storm of the season tonight and tomorrow are testing monarch nectar and host plants around town. Sunday night may bring freezing temperatures to parts of the greater Phoenix area, so get ready to cover plants again. If you already have frost-sensitive plants growing, you can give them additional protection from freezing temperatures by placing jugs of hot water around them for the night. Our sunflowers survived the last hard-freeze with this added coverage.

Monarch visiting calendula
After the weekend's cold temps pass, you can also find calendulas, fernleaf lavender, lantana, coreopsis and ageratum in local nurseries as quick nectar sources for migrating monarchs. Of course, keep milkweed available as a host plant.

Desert Ageratum
Spring Plant Sales are right around the corner! Milkweed tops the list as a monarch and queen host plant but also one of the most popular nectar sources for ALL butterflies. For the Phoenix area be sure to see Monarch Milkweed Wish List. Here are a few good general resources to consider while creating your plant shopping list:
Desert Gardening Guides - Desert Botanical Garden
"Landscape Plants for the Arizona Desert" - AZ Municipal Water Users Association
Plants for the Desert Southwest - Mountain State Nursery

Upcoming Plant Sales 
   
Boyce Thompson Arboretum
Superior, AZ
March 11 - Members only
March 12 to 27 Public

Desert Survivors
Tucson, AZ
March 12 - 18 Members only
March 19 - 20 Public   

Desert Botanical Garden
Phoenix, AZ
March 18 - Members only
March 19 - 20 Public

Tohono Chul
Tucson, AZ
March 16 - Members only
March 19 - 20  Public
  

Saturday, February 19, 2011

Mid-February Monarch Butterflies in Phoenix

Male monarch at Rio Salado
The monarch butterflies at Rio Salado are showing their age. Wings are fading with tiny tunnels of scales missing. But they are busy flying when it's warm, sunning when it's cool, and nectaring. In fact the males set up active patrols this last week over the milkweed for the first time this Spring. We know for sure at least three monarchs survived the last deep freeze at the beginning of February, but there may be more. Seep Willow continues to be a favorite nectar source, but freeze damage to the largest stand is pushing monarchs, queens, snouts, and others to seek out other plants along the creek. Fortunately many are in bloom throughout the area and a few buds are appearing on Sweetbush, Bebbia juncea, too, a delight for visiting butterflies.

Tatsuyo's monarch larva
Rio Salado isn't the only place with monarchs these days. Tatsuyo on South Mountain emailed me this week with her surprise - a few monarch caterpillars in the milkweed she was cutting back! These caterpillars survived the deep freeze of early February without any protection of any kind. It makes me wonder about any other survivors in niches around the greater Phoenix area. Of course, there needs to be milkweed present to have this kind of find. It gives a whole new perspective to what an overwintering monarch can look like. We do know that the monarch butterflies stayed longer than usual with our warm November and December. Time will tell if this is just an oddity this year or a regular event. Luckily, Tatsuyo does have more milkweed available to feed this hungry caterpillar.


Arizona Milkweed,  Asclepias angustifolia
While its still too early to prune heavy frost damage, it is time to get ready for spring migrating monarchs which make their first appearance mid-March. This is the perfect time to start milkweed seeds if you haven't already. You can find seed sources at: Bring Back the Monarchs. My favorite place is Butterfly Encounters in California. It is also very easy to harvest milkweed seed and grow it yourself. The advantage is that you know this particular local variation of the seed type is accustomed to the Sonoran Desert. Milkweeds to consider that are native are Asclepias subulata, Asclepias linaria, Asclepias angustifolia and the non-native Aslcepias curassavica. If you grow a non-native, be sure to also plant natives. In our deep freezes this winter many non-natives perished, but the natives thrived. In fact, Asclepias angustifolia is already putting out fresh, lush, new growth - a favorite for monarchs to lay eggs.

Asclepias curassavica in seed trays
 Growing milkweed from seeds is easy. You can buy trays with pellets that are easy to use. Soak the pellets in warm warm water until they expand and plant your seeds. I usually add three seeds per pellet. These seedlings were started on January 20th, almost a month ago and they are ready for transplanting.

Seedling roots ready to plant
Potted Asclepias subulata seedlings
When the seedling roots begin to grow through the pot they are reading for transplanting. This week I was busy transplanting Asclepias subulata in large pots for my yard. I find plastic or ceramic pots better since they are easy to move into the sun or shade as needed - and to protect larvae from predators. I also plant milkweed in the ground, but recommend waiting until the soil warms more for rapid growth. If your seedlings are as over run with roots as my sample above, plant it in a small pot for now. Within two to three weeks the soil should warm - keep an watchful eye on temperatures. (Notice how lush Asclepias subulata seedlings are when they are young versus the coarser stems we are more used to seeing.)

You can also easily start your milkweed seeds directly in a pot and place it in a sunny window. For pots I tend to use the moisture control plant mixtures to help prevent rapid evaporation during our hot summers. Remember indoor winter air is extremely dry, too. Add a layer of seedling mix on the top for easy germination. I also mix some of seedling soil mix to the moisture control mixture in the lower portion of the pot. The upper layers dry out more rapidly than the lower with the air exposure and I want to prevent root rot in the deeper depths. I also plant thickly for abundant lush growth for hungry caterpillars.

New growth on Asclepias curassavica
Most of the Tropical Milkweed or Bloodflower, Asclepias curassavica, in the garden died  in our deep freeze. Out of eight, only two plants are showing new growth at the soil line so far. Potted plants were able to survive since they were easily moved to a warmer location. If you haven't already, be sure to cut A. curassavica back for lusher and thicker growth. This also prevents diseases that could survive on plant leaves over the winter that could harm the monarchs or queens who visit your yard. This plant was cut back just two weeks ago and already you can see the new growth. Lightly fertilize with a half-strength fertilizer solution to help this process. Potted plants often need supplements due to frequent watering.

Enjoy the changing weather this weekend - hope we get some much needed rain!

Wednesday, February 9, 2011

Monarch Butterflies Survive the Freeze, Now Mate!

Rio Salado 2-5-11
Monarch butterflies are a tropical species and cannot survive extreme freezing temperatures. Most migrate in the Fall to Mexico or the coast of California to weather the winter. A few monarchs do not make it to these well-known overwintering sites. Small numbers scatter along the Southern United States Gulf coast and a few areas here in Arizona. Their habitat is not ideal. Monarchs at the Desert Botanical Garden and Tempe Marsh perished in the freeze of early January. When a hard freeze warning appeared in the Phoenix area forecast last week, many of us were concerned. Once again the monarchs surprised us. Despite low temperatures in the upper 20's at Rio Salado, some of the monarchs survived. After highs only in the 40's last week, Saturday was the first day warm enough to see any butterfly activity. But the skies were hazy and temperatures only in the low 60's. There was only one butterfly out anywhere - a male monarch.

Rio Salado 2-6-11
Sunday was warmer and more butterflies appeared. Two male monarchs joined several West Coast Ladies and American Snouts on stands of Seep willow that survived the freeze. Some of the outer flowers were affected, but most blooms were fresh and robust. The Sweetbush, Bebbia juncea, was stunted by the extreme cold just a short distance away. The thick tree density and winding creeks provided a protective canopy during the night's plunging temperatures.


Rio Salado 2-7-11
On Tuesday I visited Rio Salado again and witnessed two blue-tagged monarchs mating as I walked in. I followed them on their love-flight to a nearby tree and with photos and binoculars tried to read their tag numbers. It took some juggling of photos to identify them with the sun glaring off of the glossy surface of the tags. But we were able to see  576M, a male tagged on 12/28/10, and 577M, a female tagged on 1/9/11. Both 576M and 577M have been spotted several times since they were tagged in the habitat area. Monarchs usually begin mating right around Valentine's Day, February 14th. Up to now we have not seen any monarch mating activity, although the queen butterflies were mating the past month.

Rio Salado 2-8-11
 I talked to Rio Salado management who joined me to see this exciting event. There are 19 milkweed plants, Asclepias subulata, at the habitat. Most were showing the beginning of tender new growth shoots where female monarchs like to lay their eggs. We decided to add seven more host plants quickly. That evening I called Laura Miller and she joined me to plant three more Desert Milkweed, Asclepias subulata, and also three Pine-leaf Milkweed, Aslcepias linaria. When we arrived 576M and 577M were near each other at the same location. While we were digging holes for the new milkweed we saw them flutter away in the warming sun eventually nectaring again on the stands of Seep Willow nearby.

It is important to protect the monarch butterflies, larvae and pupae at Rio Salado Habitat Restoration Area and a permit is now required to monitor the area. A group of volunteers who regularly care for the overwintering area are continuing to work with Rangers and Staff to closely watch the site and keep the public from harming the monarchs, their caterpillars or chrysalids in any way. Want to help? Participate in the Pennies for the Planet campaign. Rio Salado is a recipient of funds for monarch habitat restoration including adding more milkweed, signage and educational programs.