Symptoms of fire blight below an uninfected branch on crabapple.   Image courtesy of William Jacobi, Colorado State University, Bugwood.org. 

Fire Blight: A Cantankerous Disease

August 20, 2018 | Emily Stine
Every now and then, I come across a pear or apple tree that has small branches that look like they have been blasted by a torch. Fire blight, as this disease is known, is rampant, and can cause a lot of damage to many loved flowering trees. Fire blight is a disease caused by Erwynia amylovora – a...Learn more
An example of a mushroom that is commonly found in turf spaces. Image courtesy of Norman D. Davis, Bugwood.org.

Mushrooms in the Turf – Fun Guys, or Not?

August 13, 2018 | Emily Stine
After a rain, it’s not uncommon for me to see small white-capped mushrooms popping up in the turf. Many people start worrying – does it mean the grass is unhealthy? Does it mean they’re doing something wrong? Well, in reality, they’re not really bad or good. Mushrooms feed on decaying plant matter...Learn more
Hackberry nipple gall on the underside of hackberry leaves

Oh the Gall! Strange Growths on Leaves

July 30, 2018 | Emily Stine
One of the most frequent questions I get around this time of year is “what is growing on my leaves?” while being handed a hackberry leaf with knobs on the back. These knobs are galls – abnormal growths on leaves and stems with a number of different causes, mainly insects and diseases. In the case...Learn more
Two Japanese beetles on a leaf.

Japanese Beetle Biological Control Release

July 15, 2018 | Emily Stine
Japanese beetles ( Popillia japonica ) have become numerous around Denver Botanic Gardens – I can’t walk near grapes, roses or other flowering plants and not see them. Even though these insects are beautiful like glimmering green and copper jewels, the damage they cause is not. Unfortunately, it’s...Learn more
Cryptolamus montrouzieri, mealybug destroyer, being released for biological control of mealybugs

Biological Control: Controlling Insects with Insects

July 10, 2018 | Emily Stine
When it comes to pest management, Denver Botanic Gardens ascribes to Integrated Pest Management (IPM) strategies to manage and control pest populations. One of the critical components of IPM is biological control – the use of specific organisms (often called natural enemies or biological control...Learn more
Extensive damage on columbine (Aquilegia spp.) leaves.

Leaf Miners: Not Mining for Gold

July 2, 2018 | Emily Stine
Blotchy patches, serpentine lines, and small black dots inside a clear section of leaf – these are all symptoms I look for when diagnosing leaf miner damage. Leaf miners are the larval form of a few species of flies that live within the upper and lower surfaces on the leaf and feed on the cells...Learn more
The distinct curve and twist of this stem is a characteristic sign of fasciation.

Fascinating Fasciation: A Plant Mutation

June 22, 2018 | Emily Stine
While on one of my scouting tours through the Gardens, Mike Bone, curator of steppe collections and one of the horticulturists that manages the Steppe Garden , informed me that the red hot poker plant ( Kniphofia stricta , also known as a torch lily) had some interesting fasciation going on in the...Learn more
Plant health highlight image

Plant Health Highlights Introduction

June 11, 2018 | Emily Stine
I'm the Doctor of Plant Health Horticulture Intern at Denver Botanic Gardens this summer. My internship is focused on plant health, with diagnostic projects ranging across topics including nutritional deficiencies, insect pests and diseases. I am working with horticulturalists here at the Gardens...Learn more