Jefferson County CSU Extension Colorado Master Gardeners

10/08/2026

10/08/2026

As days get shorter, trees get less sunlight. With less sunlight, trees make less chlorophyll, so the green color fades. Yellow and gold colors come from pigments called carotenoids that are already in the leaves. Orange and red colors come from anthocyanins, which trees start making in the fall. Read more here:
https://planttalk.colostate.edu/topics/trees-shrubs-vines/1728-leaves-change-color-fall/
photo: Donnetta Wilhelm

10/05/2026

Do you know how to put your garden to bed?

Everything accomplished when the garden woke up in the Spring is now time to put it to bed for Fall. We will review the tasks which give your outdoor space a proper clean up and ready it for another season. Our to-do list will include the discussion, to mulch or not to mulch, critter control, prepping tools for the next season, winter watering and overwintering plants-inside and outside.

"Putting the Garden to Bed"
October 24, 10 am - 12 pm
Jefferson County Fairgrounds ECMR
15200 W. 6th Ave, Golden, CO, 80401

This course is free but requires registration.
Sign up here: https://col.st/149fq

10/03/2026

Courses from CSU horticulture experts will cover how to deal with the many challenges to the Colorado gardener including; climate, soil, environment, insects, wildlife, and plants.

10/02/2026

The Courage Garden located behind the Jefferson County Courts and Administration Building in Golden, Colorado, is deeply important as a living memorial dedicated to innocent victims of violent crime, their families, and fallen public servants.

Established in 1995 through a partnership with Victim Outreach Incorporated (VOI), the garden serves several vital purposes:

* A Sanctuary for Healing: It provides a safe, peaceful space for crime victims and their families to find solace, rest, and reflection away from stressful courthouse proceedings.

* Honoring Fallen Heroes: It holds specific memorials for local law enforcement officers killed in the line of duty, including a prominent gazebo dedicated to Jefferson County Sheriff's Sergeant Timothy Mossbrucker.

* Community Remembrance: The garden acts as the emotional endpoint for the community's annual Courage Walk, which concludes with a symbolic dove release to honor those lost to violence.

* Environmental Education: Maintained by CSU Extension Master Gardeners, it functions as a public demonstration garden featuring water-wise, drought-tolerant plants suited for Colorado’s climate. And implements education and research-based practices in the Xeriscape and Colorado Native field gardens

Photos: Jeffrey Blake



Jefferson County CSU Extension Colorado Master Gardeners are here to help answer your gardening, lawn, and diagnostic questions! Email [email protected] to send us a message or ask a question.

09/25/2026

"As summer turns to fall and temperatures drop, insects go through an abrupt change in life style. Their activity and development largely cease, but they have strategies to survive the winter. Insect overwintering is frequently used to refer to a sort of hibernation undertaken by insects to survive the cold temperatures." Read more: https://planttalk.colostate.edu/topics/insects-diseases/1440-insect-overwintering/

Check out another Colorado State University publication with more information on how local insects handle the upcoming winter. Winter brings an important stage of metamorphosis for many insects. https://sam.extension.colostate.edu/wp-content/uploads/sites/67/2021/06/insects_winter.pdf

J. Pinta photo credit: https://commons.wikimedia.org/wiki/File:White-lined_sphinx_moth.JPG

09/04/2026

Wasps in Your Garden: Friend or Foe? 🐝🌿
Wasps may not be everyone’s favorite garden visitor, but they can play an important role in a healthy Colorado garden.

The advantages:
* 🐛 Natural pest control: Many wasps hunt caterpillars, aphids, and other insects that can damage vegetables and ornamental plants. Some parasitoid wasps specifically attack garden pests.
* 🌸 Pollination: Wasps visit flowers for nectar and can transfer pollen between plants. Colorado State University notes that wasps are important pollinators for some plant species.
* 🌱 Less reliance on pesticides: By naturally suppressing pest insects, beneficial wasps can help limit garden pest problems.

The disadvantages:
* ⚠️ Stings: Some social wasps can sting, particularly when their nests are disturbed. European paper wasps commonly nest around yards and gardens.
* 🍔 Yellowjackets can be a nuisance: Late in summer, yellowjackets may become attracted to outdoor food, garbage, sugars, and meats. They can aggressively defend their nests.
* 🏡 Nests near people can be problematic: A nest near a doorway, patio, play area, or other frequently used space may create a safety concern.

The bottom line: Not every wasp needs to be removed. Many are beneficial garden predators or relatively docile solitary species. If a nest is in a location where people are unlikely to disturb it, leaving the wasps alone can allow them to provide natural pest control. But nests in high-traffic areas deserve extra caution.

In other words: Wasps can be valuable garden helpers—just give them some space! 🌿🐝

Sources: Colorado State University and CSU Extension resources listed below.

* Wasps — Colorado State University Agricultural Biology�https://agsci.colostate.edu/agbio/ipm-pests/wasps/ �

* Beneficial Insects and Other Arthropods — Colorado State University Extension�https://extension.colostate.edu/resource/beneficial-insects-and-other-arthropods/ �

* European Paper Wasp — Colorado State University Extension�https://extension.colostate.edu/resource/european-paper-wasp/ �

* Nuisance Bees & Wasps — PlantTalk Colorado, Colorado State University�https://planttalk.colostate.edu/topics/insects-diseases/1400-1-nuisance-bees-wasps/ �

* Creating Pollinator Habitat — Colorado State University Extension�https://extension.colostate.edu/resource/creating-pollinator-habitat/ �

* Simple Ecology: The Family of Vespidae: Wasps — CSU Extension, Gilpin County�https://gilpin.extension.colostate.edu/wp-content/uploads/sites/29/2020/09/Vespidae-nests.pdf



Photo: CMG Jeffrey Blake
Image Description: wasps on hive

Jefferson County CSU Extension Colorado Master Gardeners are here to help answer your gardening, lawn, and diagnostic questions! Email [email protected] to send us a message or ask a question.