Good morning everyone and welcome to SMGB, Desert Wildflowers Edition. It’s Ed in Montana guest blogging for our esteemed hostess Ms. Frankenoid. It’s been a minor year for wildflower blooms down in the Mojave Desert. The heavy west coast storms of the last two months came too late or failed to reach over the coastal mountains to the eastern deserts to make much of a wildflower display. Which brings up several interesting questions; what factors help make a big Spring bloom of desert wildflowers, and how do you measure a bloom.
Turtleback in Cottonwood Canyon, Death Valley NP
Desert Wildflowers Defined
When we speak of desert wildflowers we are generally speaking of the desert annuals that start from seed, although blooming cacti and flowering shrubs such as the omni-present Brittlebush are frequently lumped under that term as well. The southern California deserts (the Mojave and the western Sonoran) have as many as 400 flowering annuals, while the Arizona deserts may only have half as many. Of course, not all 400 of these flower species are big showy blooms covering the desert floor. In fact, half are tiny belly plants scattered here and there that you have to work to find, not to speak of photograph successfully. Of the rest less than one hundred have flowers ½ inch in diameter or greater, and are known to be really “showy”.
Golden Evening Primrose, Lake Mead NRA, a “showy” wildflower
Beavertail Cactus, Salt Creek BLM natural area, a perennial flowering plant
Brittlebush, Death Valley NP, a common flowering shrub
Weather and Wildflowers
The weather factors that set the stage for a big bloom of wildflowers in March start back in October and November with the Fall rains that help begin the germination process for seeds scattered in the dry desert soil. Many seeds need to soak for a period of time after the first rains before germination, and then be nourished with rain every month or so until the warmth of late Winter and early Spring cause them to bloom. Like the fairy tale about the porridge, desert wildflowers need it not too hot and not too cold with not too much drying wind to flower and set seed successfully. These conditions are rare in the desert with local blooms being common every three or four years and big blooms occurring only every five to ten years or longer, usually the result of a strong El Nino weather pattern.
Sand Verbena, southern Death Valley NP
The desert annuals have amazing strategies to take advantage of these unusual conditions. Plants that can flower and set seed with little water will produce little seeds that take very little water to germinate, but will die after several hot waterless years. Plants that flower with lots of water (sometimes the same plants that use little water!) will produce large seeds with thick hulls that can survive a hundred years of hot dry conditions before germinating.
Measuring a Bloom
So how do you measure a bloom? The National Park Service in Death Valley continually mentions each year that the coming year will not be as big as the Big Bloom of 2005 when tens of thousands of acres of the park were covered with huge carpet blooms of Desert Gold, Sand Verbena and Desert Primrose. Truth be told, no one has set up a system to measure this extraordinary natural beauty. However, it is good to differentiate the types of blooms. The general public focuses on large carpet blooms as a result of the Big Bloom of 2005. Carpet blooms are created by only half a dozen of the desert annuals and are relatively infrequent. Diversity blooms are much more common, where dozens of species may be in flower at one time, but the individual flowers are scattered across the landscape and are harder to see.
Chia and Fremont Pinchusion part of a diversity bloom, Death Valley NP
Bad bloom years are all the same; Good bloom years are all different
... maybe one in five [springs] will bring a good wildflower display. All bad springs are more or less alike in that wildflowers are scarce or not to be seen, but all good years are different in that no two have the same abundance of flowers or the same combinations of species. This is because different kinds of annual wildflowers have different requirements for germination and growth.
Janice Bowers, Flowers and Shrubs of the Mojave Desert, 1998
Using this yardstick from wildflower expert Janice Bowers, 2011 was a poor bloom year for Death Valley and the surrounding areas, but the low rainfall still supported a small local bloom.
Small Carpet Bloom of Desert Gold below the Black Mountains, Death Valley NP
Color
Desert wildflowers come in a variety of colors, but there are reasons for the abundance of certain types of colors.
33% of the wildflowers are yellow, a color which attracts wide variety of pollinators, mostly insects.
29% of the wildflowers are white and are frequently quite large. Many of these flowers open at dusk and close or shrivel in the heat of the day. Their strong scents attract moths.
Shredding Primrose, Valley of Fire State Park
17% of the wildflowers are purple or lavender and 11% are pink.
7% of the wildflowers are blue, and are known to attract bees as pollinators.
Lastly 3% of the wildflowers are orange and sort of rare, like kossacks.
Desert Five Spot, the signature wild flower of Death Valley NP
Whatever the color or abundance, it is a rare treat to see these explosions of color for a few weeks every few years in the harsh landscape of the Mojave and Sonoran deserts.
Back on the Homefront
It’s been cool and windy here in my home garden, with Spring cleanup chores beginning to pile up after having been gone to the desert. The six inches of heavy, wet snow which fell yesterday didn’t help things either. But that is always the case here in the Northern Rockies, with the dirty little secret about our local climate being that spring weather is often just plain rotten for doing anything outdoors. You try to fit in a few chores like cleaning up the front flower beds or digging in the compost for the vegetable raised beds while not getting snowed upon or blown into North Dakota by the Spring storms. I won’t have any seeds in the ground until early May and no real plants placed out until late May, a couple of weeks beyond our average last hard frost date of May 12.
What’s happening in your gardens?