Thursday, January 25, 2018

How Gardening Positively Impacts Your Mental Health

Lauren Stables

Have you ever wondered why we often yearn to be outside in our garden, even if it is just to pull a few weeds? How would you describe your mood when you're working in the soil? I would describe myself in my garden as focused, at ease and relaxedit is easy to lose track of time! Believe it or not, there is some fascinating evidence that shows that interacting with soil in your garden has powerful mental health benefits. Scientists have discovered a strain of bacteria in soil, Mycobacterium vaccae, that could be responsible for the effects we feel after a day out in the garden. 

You see, this isn't a specific bacterium only found in a certain garden in a certain remote location that we would be lucky to find. This bacterium is a nonpathogenic species of the Mycobacteriaceae family of bacteria that naturally lives in all soils, which means if you have non-sterilized soil in your garden, it is probably lingering there too! This strain of bacteria is especially powerful when we interact with it because it has the power to trigger the release of serotonin in the brain. Effects of the brain releasing serotonin range from elevated mood to a decrease in anxiety. 

In addition to the release of serotonin, Mycobacterium vaccae has also been documented to increase and improve cognitive function. So while your hands are busy working to benefit the soil, the soil is busy benefiting you!
In the past 10 years there have been several individuals who have explored the link between Mycobacterium vaccae and its effects on the brain, including Dr. Mary O’ Brien from Royal Marsden Hospital in London, Dr. Chris Lowry of Bristol University, and a dedicated research team at Sage College in Troy, New York.

Dr. Mary O’ Brien explored the benefits of the bacteria while working as an oncologist, through experimental treatments with lung cancer patients. She discovered that when she inoculated the patients with the bacteria, they had a broad spectrum of positive responses. She observed that after the treatment patients had a lower occurrence of some cancer symptoms, but also had an increase in emotional health and cognitive functionoverall decreasing the emotional toll of the painful disease.

Colonies of M. vaccae grown on agar.  Credit: Laura Rosa Brunet, UCL
Dr. Chris Lowry of Bristol University was impressed by these findings in Dr. O’Brien’s published paper. He went on to expand the research by focusing on the link between Mycobacterium vaccae and serotonin production, which he explored through stress-inducing tests with mice. Some of the experiments that stood out included injecting the mice with the bacteria before putting them through a behavioral stress test that included swimming. He noticed that not only were the mice less stressed during the test and after, but that they didn’t seem to mind even the swim. He measured the stress response and the serotonin release of those mice by testing their cytokine levels. Cytokine is a part of the chain reaction that produces that powerful chemical serotonin. He discovered that the mice injected with the bacterium prior to the behavioral stress test had higher cytokine levels than the control group.

The researchers at Sage College in Troy, New York, wanted to focus their efforts on the impact Mycobacterium vaccae has on cognitive function. This team also turned to mice to test their theories, choosing the iconic experiment of placing a mouse in a maze. The research team compared the cognitive performance of a control group of mice versus those who had ingested Mycobacterium vaccae. The mice that ingested the bacterium were observed completing the maze twice as fast as those in the control group. They were also observed demonstrating half as many behaviors associated with anxiety as those in the control group. After the experiment concluded, the bacterium was removed from the mice’s diets; however, the mice who initially ingested the bacterium continued to perform better than the control group for up to three weeks.

I invite you to explore the expanding research of soil and its health benefits on us, as the areas highlighted in this blog are just the tip of the iceberg. Imagine how this type of research might affect gardening communities and how it might support those seeking garden programs for their own communities, schools and places of worship in a world that often says “Prove it.” Turns out the proof was in the soil and under our fingernails the whole time.


Health | Dirt exposure 'boosts happiness'. (2007, April 01). Retrieved January 08, 2018, from

Health | Dirt exposure 'boosts happiness'. (2007, April 01). Retrieved January 08, 2018, from

Bad is good. (2007, April 07). Retrieved January 08, 2018, from

Schlanger, Z. (2017, May 30). Dirt has a microbiome, and it may double as an antidepressant. Retrieved January 08, 2018, from

University of Bristol. (2007, April 10). Getting Dirty May Lift Your Mood. ScienceDaily. Retrieved December 7, 2017 from

“Getting Dirty May Lift Your Mood.” Bristol University: Medical News Today. 2007-04-05.

“Dirt exposure ‘boosts happiness,'” BBC News, 2007-04-01.

Tuesday, January 23, 2018

Have You Seen This Peony??

Questions from the Master Gardener Hot Line by Pat Vance

No, it isn't missing, but one of the questions to the Garden Hot Line was a request to identify this peony. If you have an idea, comment on this post, send an email to the Master Gardener Hot Line at, or call and leave a message at 215 314 8711

Thanks for any information you can provide!

Volunteers for the Philadelphia Master Gardener Hot Line have researched and answered some interesting questions. From time to time, we'd like to share some of those with you.

If you have a question about gardening, call us at 215 314 8711 or send an email to

Friday, January 19, 2018

Phenology - The Ultimate Garden Planner

Shannon Pacilli

What is Phenology?

  • Phenology is the branch of science that studies the relationship between the annual life cycles of plants and animals and their responses to climatic change.
  • It correlates natural seasonal events with weather and temperature.
People have been collecting phenological information for thousands of years. The first paper on phenology was written in 974 BC; the Japanese have been recording the dates of the first annual cherry blossom blooms since 812 AD; and in 1852, Henry David Thoreau began recording the the first flowering date for many plant species found in the US. In more recent years, phenology has been used to identify when the naturally occurring links between plants and animals are breaking as a result of global warming.  

Often phenological studies use indicator plants, such as common lilac and saucer magnolia, as signals for certain biological events and when they are likely to occur. Lilac is the cornerstone for phenological events and is particularly useful when comparing one year to the next. There are many programs in the US and Canada recording stages in the life cycle of common lilac, and climatologists use this information to study the effects of global warming. The saucer magnolia is an indicator of many early spring events. Discrete events in its life cycle, such as pink bud, early bloom, full bloom, past bloom and petal drop, can be associated with an array of insect pests.

When observing phenological events on a large scale, such as when indicator plants bloom, an event tends to progress from west to east and south to north. Hopkin’s Rule states that events are delayed by 4 days per degree north in latitude and by 1 ¼ days per degree east in longitude. It doesn’t, however, account for topography or altitude. When observing discrete phenological events, such as when a garden plant’s leaves open or when various pests are first noticed, it takes several years for patterns to develop. This data, gathered over time, can then be correlated with season, local weather conditions and regional climate changes.

Because phenology can be used to predict insect emergence and when pest control should be initiated, its role in Integrated Pest Management is perhaps the most practical application. Phenological studies enable the development of strategies that properly time controls to target pests at their most susceptible stage of life cycle. Insects are cold blooded and their growth and development directly correlate with temperature and weather. This makes them uniquely suited for phenological based predictions. Coincide, a book by Donald A. Orton, lists hundreds of insect and indicator plant associations.

Plant events and Insect emergence Links:

By studying data gathered over many years, phenologists have developed reliable correlations that aid in garden planning. The blooming time of common flowering plants can be used as a guide for crop planting dates. Because these plants are in tune with local conditions, they act as natural indicators for when conditions are right for planting.

Phenological planting guides:

We are living in a time when past weather patterns are no longer reliable and seasonal weather conditions change dramatically from year to year. The planting and harvesting schedules developed years ago do not necessarily account for “season creep”a term coined in 2006 that is used to describe the gradual expansion of the spring season. In fact, data has shown that spring is arriving a week earlier than in prior centuries. What we do know for sure is that plants and animals are reacting to these changes. The National Phenology Network calls phenology "Nature’s calendar." If we also pay attention and start accumulating notes of our own on indicator plants uniquely adapted to our gardens, it enables us to tune in to the rhythms of life. We gain the power to react to changes based on observation, to become proactive against the pests that plague us and be more effective stewards of our gardens.

I challenge you to plant a lilac in your garden and begin recording your observations, like Thoreau and the many before him.



Thursday, January 11, 2018

Stormwater management Winter de-icing

Winter De-icing
Homeowner’s Guide to Stormwater Management            Philadelphia Water Department
As snow piles up in the winter, we oftentimes turn to 
salt to melt snow and ice. Salt, however, causes adverse environmental impacts, especially on our streams and rivers, our drinking water source in Philadelphia. Excess salt can saturate and destroy a soil’s natural structure and result in more erosion to our waterways. High concentrations of salt can damage and kill vegetation. Salt poses the greatest danger to fresh water ecosystems and fish. Studies in New York have shown that as salt concentrations increase in a stream, bio- diversity decreases. Excess salt can seep into groundwater and stormwater runoff. Effective ice control can help prevent excess salt runoff to our waterways.
De-icing in the Winter
There are many alternatives to salt including potassium chloride, calcium chloride and magnesium chloride, corn processing byproducts, and calcium magnesium acetate (CMA). Most can be found in your local hardware stores under various trade names, so check the labels for chemical content. While these alternatives can be spread in a dry form or sprayed as
a liquid, their best use occurs when they are used with salt. They tend to increase the efficiency of salt thereby reducing
the amount that needs to be applied. When over-applied, all chloride compounds can be harmful to the environment. Non- chloride corn byproducts recycled from mills and breweries have been shown to be effective de-icers as well. While they are often advertised as organic or natural, they can have extremely high phosphorus content, a major water pollutant. Numerous studies have shown calcium magnesium acetate (CMA) to be the most environmentally benign de-icer. Many northern states use CMA on roads in sensitive areas (wetlands, endangered species’ habitat, drinking water supply, etc.). A couple of disadvantages with CMA however, is that it does not work
well below 25° Fahrenheit and it is the most expensive de-icer. Because all de-icers can be harmful to the environment when applied in excess, the best strategy is to reduce the use of these chemicals as much as possible.
    The first line of defense should simply be to shovel sidewalks and pathways to keep them clear and to prevent ice from forming. Also, consider that salt and de-icers are not effective when more than 3 inches of snow have accumulated.
    Consider the temperature. Salt and calcium magnesium acetate (CMA) have a much slower effect on melting snow and ice at temperatures below 25° Fahrenheit.
    Track winter weather and only use salt and de-icers when a storm is about to come through. If a winter storm does not occur, sweep up any unused material, store, and reuse for the next big storm.
    Apply de-icing products discriminately, focusing on high-
use areas and slopes where traction is critical. Apply the least amount necessary to get the job done. This will save money in product costs and will also help minimize property damage to paved surfaces, vehicles, and vegetation.
    Reduce salt and other chemicals by adding sand for traction.
    Become familiar with various de-icing products and wetting agents such as magnesium chloride and calcium chloride, which can improve the effectiveness of salt and reduce the amount needed.
    If you observe ongoing issues of ineffective ice management or examples of poor application, such as excess piles of road salt left to disperse, share your concerns with the property manager of your residence or business, or with the City of Philadelphia Streets Department. The Streets Department Hotline is 215-686-5560 and their website is streets.
    Plant native vegetation that is salt tolerant in stormwater drainage swales and ponds that may receive salt-laden runoff. Not only will these native species have a greater chance for survival, but they will continue to act as an effective buffer for our local waterways.
    Store salt and other products on an impervious (impenetrable) surface, such as a basement floor, to prevent ground contamination. Also store products in a dry, covered area to prevent stormwater runoff.