After 3 years of only minimal gardening here in Arizona (tomatoes and basil in pots was the extent of it) I’ve decided that I can’t live without growing something other than cactus. So this past weekend I headed over to Native Seed Search to get some instruction in desert gardening and pick up some seed for crops suited to the hot, dry desert. I’m still figuring out how to set up my garden, but so far I’ll be growing popcorn, Teosinte (the mother of all corn varieties) string beans, devils claw, Hopi sunflowers , and some melons and beans that the Tohono O’odham people have been growing here for centuries. I also learned that spring feels early here, so I can start planting right now.
That made me wonder when spring is coming for the rest of the country, so I did a quick search. The National Phenology Network says that Spring is 2 to 3 weeks early this year in the southern U.S. and they’re expecting this trend to continue moving north on the continent. You can see what’s happening so far this year in this map.
How do we know spring is early? Phenology!
Phenology is the study of recurring plant and animal life cycles. It helps us understand the temperatures and climate conditions plants need to begin growing each Spring. In fact, the National Phenology Network has a set of “spring indices” based on information about the accumulated warmth required for native and cultivated plants to leave dormancy and begin to grow. Using this information they’ve developed a set of algorithms (think fancy math like what Google uses to figure out what you’re looking for) that can use the data from any weather station to tell us when spring, or plant growth begins.
We started gathering this information in the 1950s when Bozeman, Montana Professor Joseph Caprio created the “Lilac Network.” Lilacs bloom in early spring, so they’re a good indicator of when spring has sprung. Caprio enlisted citizens across Montana to send in their observations of lilac bloom dates and temperatures. By the 1980s the network had spread nationwide, and ultimately it became the National Phenology Network. Based in part on decades of lilac data, as well as lots of other information gathered by citizens who signed up to monitor temperatures and provide observations on plants and animals, we now know that spring is coming 6.8 days earlier than it did in the midwest in the 1950s when Caprio began his observations. We also know that normally spring is showing up later and later every year in the south.
Thanks to satellites we can monitor vegetation and its response to temperature and precipitation changes at intervals of only a few days. With that information and all the data available from the National Phenology Network, scientists are working on ways to predict spring for the benefit of farmers and ranchers everywhere. You can be part of this by participating as a citizen scientist. Just check out their website here for instructions on how to sign up as an observer. You can also follow what’s happening with spring on their facebook page.
I love spring, but it’s such an unpredictable season. Even when it’s arrived, it doesn’t seem like it’s sure it will stay at first. Rachel’s kids were playing outside in shorts on Saturday and it snowed on Sunday! Here’s hoping for a gentle spring for all of us.
Kathy and Rachel
