Looking up at the green tops of trees.

An interview with Robin Eng, Restoration Gardener 


Tell us about the typical tree planting process? 

Tree planting begins with tree growth. We get all of our trees from various nurseries in Western Pennsylvania, and they come in a wide variety of sizes. The tiniest restoration trees we get are less than a foot tall and come in quart-sized containers. The largest container trees are about 25 gallons and can weigh well over 100 pounds. We also get balled and burlap (B&B) trees. These trees can be much larger than container trees and can weigh over 300 pounds. Although they start bigger, B&B trees take a lot more work to get established because the nursery cuts off about 75 percent of their roots when they prepare them for sale and shipping. If you have patience, a large container tree can often out-grow a B&B tree within five to ten years simply because they do not have to expend so much energy re-growing a root system. 

Choosing the right tree for the right place is also very important! We have trained staff who can evaluate site conditions to ensure we plant trees with the maximum chance of survival. For instance, planting under telephone wires prompts us to select a tree with a shorter mature height. Soil conditions also need to be considered; areas near springs or creek beds are prone to soggy soil while hilltop sites can be more hot and dry, so we must select trees that will thrive in the location-specific conditions! 

Once trees are selected and have arrived on site, tree planting is similar to any other planting, with a few additional considerations - the most important being the root flare! "What is the root flare," you ask? The root flare is the transitional area where a tree trunk meets the ground and becomes wider to support roots' radial growth. We take great care never to bury the root flare when we're planting trees. A lot of crucial gaseous exchange occurs in this part of the tree, and so burying it in soil or mulch can dramatically reduce the survival and lifespan of these new trees! 

The final steps for tree planting are where we prepare the tree for long-term maintenance. When we plant trees in grass-dominated landscapes, we like to add mulch in a three-foot radius (with a three-inch donut hole in the middle not to cover the root flare!) and give the trees a good watering to get them started. We also add stakes on two sides with arbor ties to help keep the tree trunk straight as the disturbed soil from planting shifts initially and settles in. The mulch ring and stakes also make good indicators, so lawn mowers don't get too close to the tree trunk or compress the new roots trying to grow.  

But wait, there's more! White-tailed deer are also a significant stressor on new park trees. Whenever we plant new trees, we need to install some form of deer protection. This protection comes in a few different formats (e.g., light tubes, tree cages, deer fences, and bark guards) depending on the new trees' size and location and typically requires upgrades as the trees grow.   

Once tree plantings take place, what does the maintenance process entail for ensuring tree growth?  

Trees live a long time, and tree maintenance is a long-term practice as well. Typically, from the day we've planted a tree, it stays on our maintenance schedule for 10-20 years! For B&B trees, the first two to three years of maintenance is both time-consuming and crucial. Since these trees stress from having their roots removed, we need to make sure they are getting enough water to develop a healthy new root system. This practice means getting them 10 gallons of water weekly or bi-weekly during the summer (depending on the weather) for two or three years! After a few years, the trees do not need such extensive watering. Still, pruning efforts continue periodically for another ten years to help the tree develop with a healthy and structurally sound form. 

On average, how many trees does the H&F team plant per year? 

Tree planting is a big part of our work every spring and fall. This spring season, we are planning to get 135 B&B and 237 restoration trees in the ground! 

Why is it essential that we plant and maintain a robust urban tree canopy? 

Pennsylvania translates literally to "Penn's Woods," which can return the favor in the form of shade, beauty, air purification, carbon sequestration, and stormwater mitigation (among other things!). 

Why should people support this kind of work? 

Few things have as many and as a wide-reaching benefits as healthy trees in a community. Achieving these benefits takes dedicated support and patience, but the long-lasting positive impact on our community and environment is unparalleled. Investing in trees is an investment in the future, and the future begins now.