When it comes to spring
wildflowers in the Sonoran desert, timing is everything. There is a common misconception that if we get
plenty of rain in the spring, wildflowers will abound. But truly eye-popping
displays of desert annuals require a steady dose of winter rains beginning in
November and lasting through February in order to germinate and grow a healthy
crop of seedlings that will eventually flower. Lots of other factors come into
play, but the records show that a cumulative rainfall of over four inches
through the winter, preferably not in one giant storm, is the most reliable
predictor for the abundance of spring wildflowers. This was the case for our
most recent banner years, 2001 (7.07”), 2005 (7.72”) and 2008 (4.35”), when
entire hillsides glowed orange with poppies, blue with lupines and valleys
blazed hot pink with purple owl clover.
A decent monsoon the
previous summer will help, but is less important than a consistent series of
winter rains that keep the soil moist. In fact, the same banner years listed
above actually had below average (< 2”) monsoon rains the previous summer. Cooler
temperatures also help keep the evaporation levels low and tender seedlings
from frying in the hot sun. Even if you want wildflowers in your yard, you need
to scatter the seed no later than early November and then water them weekly for
the next three months if you want to see some action.
So what’s the forecast for this year’s desert
wildflowers? I'd say mild to moderately stunning. Records from the
National Oceanic and Atmospheric Administration (NOAA) show that while the 2012
monsoon season was slightly above the 100+ year average of 2.71 inches, we’ve
had a relatively dry winter. The gentle rains in early December and late January
only generated a cumulative rainfall of about 2.30 inches for the Phoenix
region. More rain in February and March
can help, but it’s usually too little, too late. However, we should always be
grateful for any amount of rain in the desert!
The good news is that there are always wildflowers
somewhere; you just have to know where to look and plug into the wildflower
watch networks to learn where the weekly hot spots are. Because rainfall varies a lot across the
region, certain hills may be lusher than others, even compared to somewhere
only a few miles away. Even a scant quarter inch of rain can make a big
difference. In a dry year, north-facing hillsides are good places to scope
out, since moisture will hang around a little longer on the shady sides of the
hills. Even the north sides of large boulders and the shade of large trees will
often be havens for annual wildflowers.
Although annuals may be sparse this
year, many shrubs, perennials and cacti will bloom profusely, since they don’t
have to start from seed. This is a great year for desert hyacinth (Dichelostemma capitatum), a delicate
perennial plant that harbors a bulb deep below the soil surface. Thousands of
slender succulent stems pierced the stony soils in desert hills throughout the
region by early February, and will show off lavender blooms by early March.
Bright orange globe mallows are another abundant hearty perennial commonly seen
along roadsides throughout the desert. Flowering shrubs like brittlebush, wolfberry and
ratany will always find energy to bloom, even if there is next to no rainfall.
In the Happy Valley region, you’re likely to find some
brilliant patches of wildflowers in the Sonoran Preserve, east of Highway 17,
just north of Jomax. Cave Creek Recreation Area north of Carefree Highway at 32nd
Street and the Pipeline Trail at Lake Pleasant are also historically
floriferous. Wherever you go, be sure to
appreciate the miracle of each and every blossom.
