The Root issue

FirewoodGarden Caregarden TriviaPlant Health Care
Written By Peter Morris

Roots

 Roots are in a perpetual search for new sources of food and water. This continuous growth habit is never ending. They move away from the center of the plant and can go in any direction except up, or into sunlight.There are substances in the roots sensitive to gravity and this keeps them going downwards.  The roots also won't grow into sunlight because other chemicals steer them away from damaging solar rays. 

Older roots are covered in bark ! – and they can't absorb water !

 

Root growth and hormones

 The growing habit has a limit - which its length and breadth are determined by the genetics of the species.  However, the actual qualities of the soil environment they are in when growing will affect them too.Most importantly, it is this growing activity that produces hormones which stimulate the growth of shoots and leaves up above in the sun! 

New roots (white) absorb water and nutrients while older roots (tan, red, brown) are there to just help anchor the plant.

 

Soil volume

 Generically speaking, a plant wants to spread out into a soil volume that is 2 to 4 times the diameter of the crown and about 2 ft deep.  For example a rose shrub may consume 12 cubic feet of soil (3' wide x 2 x 2' deep). 

to thrive - a rose wants a cube of soil 3' x 2' x 2'

- think about that ! 12 cubic feet !!!

 Trees however are of a greater magnitude, they are more like 4 times the crown and also 2' deep but with a much deeper taproot that grows straight down and is used for anchoring.A small 10' crepe myrtle tree may need about 60 cu ft of soil and go down 3' at the center. Imaging a 25' oak tree !!! 

Diagram illustrating the soil volume of a plant (2 to 4 times the diameter of the crown and about 2 ft deep)

  

Pot Bound

 When the soil volume is totally consumed by roots, no new roots are produced. We call this root bound or pot bound. The canopy at this point stops growing as direct response to the lack of hormones made by new roots.This is a major issues in growing trees in planters.  On rooftops – due to soil weight restrictions, its almost impossible to give it the soil volume it needs or wants.Most plants we install in planter boxes are by default placed in a limited soil volume environment. In less than two growing seasons, these plants would have totally consumed the entire soil volume available. 

Typical pot-bound plant with encircling roots.

 

Water and nutritional stress

 In addition to no new growth, root bound plants will suffer from heat damage and leaf scorch. Simply put, the amount of water needed is less than is available in the soil volume.Insufficient soil volume leads to not enough roots and not enough water in the soil for the amount of water required. Watering more frequently does not always help. The soil may actually be wet – but its volume is too small and there are too few roots.For this same reason they will also have a severe nutritional deficiency, as mineral absorption occurs primarily via new roots. No new roots means no eating !In severe stages, this will affect blooming, and the ability to handle the extremes of heat or cold, or to ward off diseases and pests. 

Symptoms of heat and leaf scorch due to insufficient water in the soil.

 

Girdling and encircling roots

 When planted in a pot or container, the natural spreading out habit creates another problem.  As the root hits the planter wall and starts going around the pot it forms encircling roots and is the main cause of girdling.Girdling by roots may actually lead to the partial or complete death of the plant.  The roots wrap around the main trunk so tight that they actually stop the flow of sap from above and the roots die of starvation.  It is a slow and cruel process ! Sometimes a girdled stem even starts putting out shoots above the strangle point. 

An crossing root that is girdling another main root from the trunk !

 In trees, large strangling roots are rarely successfully removed without further damage to the plant. It is best to not remove a girdling root more than 4” in diameter. That is why its important to prune off those offending roots when they are small, usually in the Spring, and before the buds open. 

Call Plant Specialists TODAY !

We have experts that can help check if your roots are healthy!

 

PLANT SPECIALISTS

GREENING NEW YORK FOR OVER 52 YEARS !

 Article written by our Staff Horticulturist, Peter B Morris, BSc, MSc, MBAAll photographs used with permission @SHUTTERSTOCK   

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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