Category Archives: Plant Health Care

Plant Health Care, or PHC, is “a holistic approach to plant care that focuses on the health and growth of plants. The practice of Plant Health Care was developed by the International Society of Arboriculture Research Trust, Tree Care Industry Association, and the USDA Forest Service.” –

pbd Pruning Guide : Selective Hand Pruning

Pbd : HOW TO PRUNE | adele medina o’dowd 2/3/2020


1st step : prioritize pruning plants in the yard based on time of year and what looks healthy or not

2nd step : what is plant’s natural growth habit?  — is the natural shape or form of a plant ever square? 

3rd step : think about the job/role of the specific plant within the yard – what is its purpose? Screening, Flowers, Foundation, Seasonal Interest, Wildlife Habitat, Fragrance, Soil Retention, Shade, what?

UNDERSTAND that plants in the wild do not grow into rigid geometric shapes.  Most of the time, people want their plants to look more like they do in nature, softer. When you are done, the best results will be evident if the the yard does NOT look “pruned”, it should just look healthy/better.

APPROACH pruning a shrub or tree with the strategy of “Selective” hand pruning. Expect to prune branches at different levels and layers within the canopy. Careful not to injure foliage and bark unwittingly, causing undue stress and literally cutting off food production in leaves and nutrient flow in the vascular system.


  • CLEAN TOOLS OFTEN Use clorox wipes or dip tools between plants, beds and yards
  • Careful NOT to spread disease!  Looks for pest infestations and also good predators!
  • Have a bag or blanket right next to you as you prune to keep infected trimmings and infested foliage together and OFF the beds (you can spread box blight with leafblowers)


Look at last year’s growth — know what you are trying to achieve.  Where are you encouraging growth? Are you trying to make it smaller?  Don’t rush it. It might take more than 1 season. Plants are resilient, but they keep changing.  Don’t expect to prune them into a shape on the outside that they will retain — doing that will cause them to become unhealthy “empty shells”.

  • Pruning too much at once can stress the plant — prune no more than ¼ to ⅓ 
  • Start by pruning out any dead or weak wood (always)
  • Careful not to injure Branch Collars
  • Next let light and air in — make “holes”& top branches shouldn’t hang over bottom ones
  • Then begin shaping the whole thing based on your vision and knowledge of the plant’s natural form, move forward, stand back, blur your eyes, look at the plant or group, as a whole
  • Prune longer branches so they don’t break in winter and get leggy  
  • Stagger and vary the depth of your cuts inside the plant
  • Consider the interior branch architecture — what should that look like?
  • Careful with hollies and other plants that grow from new cuts — “hide” cuts further inside
  • Careful in aug/sept — let them remain a bit more rough to conserve energy and foliage
  • Recall that evergreens shed leaves 3 times/yr and sometimes it’s good just to shake or hand remove the brown leaves or needles that are hanging on


One of the most beautiful explanations of an elegant natural system : Compartmentalization of Decay in Trees or CODIT

Developed and described by Alex L. Shiga Plant Pathologist, U.S. Department of Agriculture, Forest Service, Northeastern Forest Experiment Station, Durham, New Hampshire and Harold G. Marx Research Applications Staff Assistant, U.S. Department of Agriculture, Forest Service, Washington, DC

Watercolor illustrations by David M. Carroll, Warner, New Hampshire. READ the full text and VIEW the clear illustrations.

“The CODIT system is based on two major points. First, a tree is a highly compartmented plant. Second, after a tree is wounded, the resulting defects are compartmentalized”…

by Alex L. Shiga and Harold G. Marx