Sunday, July 9, 2023

Wet Year So Far, Colorado Front Range

 It has been a wet spring and early summer in northern Colorado. Many days have had rain. I measured a single day's rain at 1.1", the wettest single day in the 5 years I've had a backyard rain gauge. Denver had its 4th wettest May and wettest June ever recorded. Denver has exceeded its average annual rainfall with half the year to go. I'm 50 miles to the north and we don't get quite the same storms, but we're very, very wet too.

In consequence, the countryside is green and plants everywhere are thicker, taller, and flowering more.

Devil's Backbone Open Space, Loveland, CO
  Devil's Backbone

Here is a look at some of them, along Devil's Backbone Open Space in west Loveland. 

The grass along the trail was about 1/3 taller than usual, with lots of stalks and flowerheads.

grass along the trail

Plants of many species seemed loaded with flowers.

This is how I usually see prairie spiderwort, Tradescantia occidentalis, 

prairie spiderwort, Tradescantia occidentalis
prairie spiderwort, Tradescantia occidentalis, 2014

This is how prairie spiderwort plants look this year (a single plant):

prairie spiderwort, Tradescantia occidentalis
prairie spiderwort, Tradescantia occidentalis  

Slimleaf milkweed, Asclepias stenophylla, has 5 clusters with more than a dozen flowers 
(It hanging on a slope)
slimleaf milkweed, Asclepias stenophylla
slimleaf milkweed Asclepias stenophylla

The blue larkspurs (Delphinium, several species) formed large splashes of color, not the one or two shoots I was used to spotting:

larkspurs, Delphinium
Larkspurs on the hillside this year.

Soapweed yuccas, Yucca glauca, had long stalks with lots of flowers

Yucca glauca

Of course the weeds were large too: 

field bindweed, Convolvulus arvensis
field bindweed, Convolvulus arvensis

Lambs quarters, Chenopodium album, can flower at 3 inches high, but this one is 3 feet high. I didn't look carefully, we have several native Chenopodium species that look very much like C. album, and grow in similar habitats, so this might well be a native. Either way, its having a grand year.

Chenopodium species
tall Chenopodium amid the grasses

This picture below shows lovely green grass with long awns, bobbing in the light breeze. The catch is, these are Hesperostipa comata, needle and thread grass. The long awns disperse the plant by lodging into things, for example dog fur, socks, soft shoes, and thin jeans, and then the twisting to drive the pointed tip of the seed into the ground, or wherever they are sticking. Ouch. It is going to be a bumper year for needle and thread grass too.

needle and thread grass, Hesperostipa comata
needle and thread grass, Hesperostipa comata

Most ecosystems are limited by water (because the plants expand until water is limiting). The Front Range with about 15" of rain a year is usually dry to very dry by midsummer. This year is highly unusual with water enough for all the plants, so we have unusual levels of growth and flowering.

It is also a great year for some insects

Here, aphids are consuming the yucca flowers. If you look carefully, you can see two ladybugs hunting the aphids. 

yucca with aphids and ladybugs
yucca with aphids and ladybugs

I don't recognize either the plant or the beetle here, but clearly the big new leaves of the plant are delicious:

beetle eating leaves

Somewhere up the food chain, likely spiders, lizards, and birds are benefitting from a good year for insects.

Devil's Backbone vista
I was a grassland ecologist, so I have to add: it isn't a good omen for wildfires. While it is very wet, yes, that suppresses fires. Colorado is delighted to have no counties under drought conditions this week. But if it dries out, as is usual, then all those extra leaves make more fuel for a wildfire. Don't get complacent about fire prevention because there was a wet spring. 

Ah, but it has been SUCH a wet spring and early summer. We are not likely see a year like this for decades. Like the plants and animals, take advantage of it if you can.

Comments and corrections welcome. 

Kathy Keeler, A Wandering Botanist


  1. This comment has been removed by the author.

  2. Love the Hesperostipa comata. The tall grasses might be Thinopyrum obtusiflorum, and the last might be Hordeum brachyantherum, though I could be wrong.