ALLELOPATHY

Design and InstallationGarden Caregarden TriviaIndoor plantsLighting and IrrigationPlant Health Care
Written By Peter Morris

 

Our observations

 

Many years ago we noticed how when planting sweet potato vine into containers for a summer display - all the hibiscus also planted with it would stop flowering soon after ! We also noticed how some annuals didn't do well in pots with marigolds. And nothing liked to be in a pot with a sunflower!

We were curious and decided to investigate!

 

Tropical hibiscus are sensitive to substances in sweet potato vine (Ipomoea)

 

Our Discoveries

We discovered that some plants produce chemicals that are not intended for defense against insects or animals but against other plants. These are called Allelopathic plants.

It is a phenomenon which secures a better competitive advantage from the immediate environment. The toxin producer thus benefits from less crowding, and more water and mineral resources at their disposal.

A good example is manzanita trees where they forms circles underneath them where nothing can grow.  Pine needles do the same.

 

Pine needles are very allelopathic

 

The allelopathic chemicals

 

Some of these chemicals can outright kill other plants.  A few species produce deadly toxins to just seeds or seedlings.  Others exude chemicals to suppress the flowering in nearby plants or affect their growth development or reproduction. Nasty !

Depending on the particular plant - the substances could be released via sap, leaves, bark, through their own root systems, or when their plant parts decay.

 

Sap and gum is a common method of dispersing substances

 

The common bottlebrush plant (Callistemon citrinus) actually produces an herbicide.  So much so that the compounds have been commercially developed into a product called - of course - Callisto!

 

Common bottlebrush

 

Our list

 

Over time we have accumulated information on allelopathic ornamentals. Our knowledge is anecdotal, collected over many years from actual observation. Sadly, the research literature mainly focuses on commercial crops and not a lot is studied about ornamental's.

Our main concern is to identifying these plants to enable using them singly or in the right combinations to avoid any flower suppression or damage. It is made up of those plants we mostly use in our gardens, or those that commonly grow wild in the Northeast.

At Plant Specialists, our Design Team always consults with our in house list of known allelopathic plants. Our Garden Care team also knows quite well which plant combinations to use and install to avoid any problems - We know our stuff!

Here in NYC the common weed tree - "Tree of Heaven" - Aillanthus altissimus is a good example of allelopathy.  Goldenrod (Solidago genus) and the common sunflower (Helianthus annus) too.

All our Plant Specialists customers enjoy the knowledge of our full list!

 

Sweet potato vine, Salvia, Calibrachoa and coleus do beautifully together !

 

For expert advise on what to plant together !

Contact Plant Specialists today!!!

 

PLANT SPECIALISTS

GREENING NEW YORK FOR OVER 52 YEARS !

 

 

Article written by our Staff Horticulturist, Peter B Morris, BSc, MSc, MBA

All photographs used with permission @SHUTTERSTOCK  and our own customers gardens !

 

Peter Morris

Peter was born and raised on a beautiful green island in the midst of a tropical rainforest. He was introduced into the world of plants at the age of six when his grandmother, an avid Spanish gardener herself, asked him to help her grow seeds for her pepper garden. He was hooked! By the time he was a teen, he had his own rose and orchid collection numbering in the hundreds. Botany was in his blood, and that is what he set out to study.

His passion brought him to NY in the late seventies to further his education. His tenacity allowed him to work full time at Plant Specialists while he completed a MS in Plant Biology. As a manager at the time he felt unsatisfied with his knowledge of business and business processes. Peter felt compelled to learn, so he then pursued and completed an MBA in Quality Management within a few short years.

Peter’s other passion is teaching. His natural ability is quickly consumed by our staff in all subjects in Botany, Horticulture, and Landscaping. He created an immense reference library of more than 3,500 plants providing an invaluable resource for our staff.

Peter’s breadth of knowledge and wisdom allows him to effectively diagnose the needs of plants. Sometimes just by walking into a garden he can create a prescription that fixes even the hardest issue. He is our Staff Botanist, Diagnostician, and all around Mentor. Recently, he has put his immense knowledge and skills into developing a new department that focuses on Plant Healthcare. As he puts it, “Magic through Science”. The PHC staff that surround him have avidly consumed his teachings. Substantially developing their own plant wisdom, many have taken on difficult plant health issues with spectacular results.

Plant Healthcare has been an instant success with customers! The proper treatment of insects and diseases including Organic methods has made pest control a necessity for every plant. Correcting hormonal imbalances caused by planting in containers or refurbishing soils leached of nutrients by irrigation systems are big challenges PHC has become quite comfortable addressing. The scientific approach to the complex demands of keeping plants healthy in our harsh city environment has made many a customer say WOW!

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