CO-Horts Blog

Friday, June 28, 2019

Let's Celebrate Pollinators Every Week!

Posted by: Lisa Mason, Arapahoe County Extension

Last week was National Pollinator Week! We should celebrate pollinators every week because they provide so many benefits to humans and ecosystems! Many people are well aware that bees are declining all over the world for a variety of reasons including habitat loss, pesticide use, parasites, diseases, climate change, etc.

Pollinators include bees, bats, flies, beetles, wasps, ants, butterflies, moths and some small mammals. Bees are among the most efficient pollinators because the pollen sticks to the hairs on the bee.

Two-tailed swallowtail, Papilio multicaudata. Photo: Lisa Mason

Why should we care about pollinators?

Pollinators provide valuable ecosystems services. They transfer pollen grains from one flower to another which enables the plants to reproduce. Here is a closer look at the value pollinators have to humans and ecosystems.
  • 75% of more than 240,000 plant species rely on pollinators for reproduction. 
  • The global production of crops that depend on pollinators is an industry worth up to US $577 billion annually. 
  • Bees help to pollinate 1/3rd of the human diet including the most nutritious part of our diet—fruits, vegetables and nuts. 
  • In addition to crops, they pollinate the food for livestock that contributes to the meat and dairy industry.
Our planet has an incredible amount of bee diversity! Most of us are familiar with the honey bee (Apis mellifera), a non-native bee species to the United States. The honey bee was brought over from Europe in the 1600’s. In addition to the honey bee, we have approximately 20,000 species of bees worldwide. We have over 900 species in Colorado!

A green metallic sweat bee, Agapostemon sp. Photo: Lisa Mason
A leafcutter bee, Megachile sp. Photo: Lisa Mason

Where you can you find the bees?

Bees come in all sizes, shapes and colors. Take a close look at the flowers in your garden this summer. You are likely to see bees buzzing around in pollinator-friendly plants! To get an idea of the bees that are in your garden, check out the Native Bee Watch Citizen Science Field Guide.

When the bees aren’t foraging in flowers, the females are likely at their nesting site. Of all the bees in the world, approximately 90% are solitary bees which means they mostly do not interact with other bees with the exception of mating.  Of those bees, about 70% live underground and the other 30% are cavity nesters. Solitary bees have a one-year lifecycle.

Some bees are generalists or polylectic, meaning they collect pollen and nectar from a variety of flower species. These bees are opportunistic but still may prefer certain flowers. A specialist or monolectic bee only feeds on a specific plant species. Monolectic bees have generally coevolved with a specific plant species meaning the plant and bee depend on each other for survival.

A squash bee, Peponapis pruinosa. Photo: Lisa Mason

Do you enjoy pumpkins and squash?

If so, thank a squash bee! They are a great example of a specialist bee. In Colorado, we have one species, Peponapis pruinosa. Squash and pumpkin plants need these bees to pollinate the flowers so they can reproduce. They have special pollen collecting hairs on their hind legs that helps to transport the pollen. One research study showed that not only were squash bees more efficient at pollinating squash plants, but they pollinate earlier in the morning when pollen and nectar is readily available. By the time honey bees start foraging, the squash bees have already pollinated the flowers. If you look in the early mornings at the big yellow flowers on your squash or pumpkin plants, you are likely to see squash bees in the flowers.

Squash bees and other native bees need your help! By developing habitat in your yard, you can provide food, shelter, water and space for native bees and other pollinators. Check out this blog post on creating pollinator habitat. You can also check out the following fact sheets:

Have fun observing bees in your garden!

A cactus bee, Lithurgopsis apicalis. Photo: Lisa Mason

Tuesday, June 25, 2019

Remembering the Irises of Springtime

By: Sherie Caffey, Horticulture Agent, CSU Extension-Pueblo County

One of my favorite parts of spring time is seeing all of the irises blooming in my neighborhood. So many people have beautiful clumps of these showy spring flowers and I love to see all of the different colors they can come in. These flowers are not only showy, but very easy to grow which makes them even better! By now the iris blooms have faded, but their unique fan like foliage still has me remembering their beauty.
Bearded iris
The two most common types of iris that people grow in Colorado are Bearded iris and Siberian iris. Both species come in many forms and colors. Their sword shaped leaves are very attractive when the plants are not in bloom. Both types of iris have three erect petals called standards, and three petals that droop down, called falls. The leaves are arranged into a fan shape.
The falls of Bearded iris have a neat looking, hairy center, which is where they get their name. They do best in full sun, and dry, alkaline soil. If you are from around here, then you know we have plenty of full sun and dry alkaline soil, making bearded iris a perfect addition to your landscape. Siberian irises have skinnier leaves than the Bearded irises, and prefer moist soil. You will often see them naturalizing near stream beds. They are also a great choice for your landscape if you have an area that stays pretty moist and gets full sun.
After your irises bloom in the spring, you should cut the flower stalks back so the plants can focus on storing energy for the next year. If you haven’t done this already, now is the time! If you want to cut the leaves back, wait until fall or late winter. Alternatively, you can go for a more natural look and not cut them back at all. The old leaves will end up acting as a natural mulch and eventually break down and improve your soil.
Siberian iris
Every three to four years, you will have to divide your iris clump so that it does not become overcrowded. It is best to divide after blooming is finished for the year, but no later than August. Use a garden fork to gently lift each clump of leaves from the soil, below ground you will find a bulb like structure called a rhizome. Only re plant healthy looking rhizomes. Trim the roots back a little bit, and also trim the leaves down so they are a few inches long. You can re plant this rhizome to extend your iris patch, start a new patch, or give them away to friends so they can start an iris patch. When you re plant them, the rhizome should be no deeper than one inch under the soil. Be sure all of the leaf fans face the same way. Spread out the roots and firm the soil around the rhizome. Need a visual? Check out this video:

Monday, June 17, 2019


By Andie Wommack, Douglas County

Xeriscape, WaterWise, and now ColoradoScape. These are all terms used to describe landscapes that use less water. ColoradoScape is the newest term that is being used by some to promote water-conscious landscaping. There are seven principles of xeriscape: plan and design for water conservation, improve the soil, create practical turf areas, select appropriate plants that require less water, use mulches, irrigate efficiently, and maintain the landscape properly.

One common misconception when people hear “xeriscape” is ZEROscape. Some water districts are now rebranding the concept of xeriscape as ColoradoScape. This past weekend was the Castle Rock Parade of Gardens hosted by the town of Castle Rock and Castle Rock Water. This event showcased several gardens throughout Castle Rock demonstrating different styles of ColoradoScaping. Each location showed different styles of low-water landscapes.

The garden I worked at was titled “The Secret Garden” because the main garden was hidden away by trees and other hardscapes. The couple planned the garden together, blending stone, brick, mulch, and plants to create variety throughout their landscape. Low-water landscapes can be interesting and colorful.

Hardscapes like paths and stone can add different textures and colors to your landscape.
Using different plants also add variety of colors and textures. Look for plants with different leaf sizes and shapes.
Rain barrels can add a beautiful accent to your landscape. This has a regular hose for watering and a soaker hose attached.
Containers and yard art can easily add color and interest without requiring any extra water.