Trees and shrubs grown in containers are great for transporting easily and do not require the same labor as bare-root or balled-and-burlap trees. While these are great, they can also lead to root problems if not prepared and cared for properly. Growing large root system inside the container can lead to girdling roots or can strangle the trunk. These trees can also develop dry soil and stress after transplanting into soil. Be sure to prepare your containerized trees and shrubs properly.

USDA Plant Hardiness Zone Range: 5-9

Mature height: 60 feet

Mature width: 30 feet

April is the month for trees as we celebrate Earth Day and Arbor Day. It is usually a wet month with aspirations of warmer weather and planting in the garden. Our tree of the month for April was inspired by the Michigan State University Forestry Club that came to visit the Wet Mesic Flatwoods on Belle Isle the last weekend in March. Deep in the unique natural community lies a rare and special species of tree called pumpkin ash (Fraxinus profunda). This species is limited to deep swamps and is found mostly in southeastern Michigan. It is a great tree to scavenger hunt for those who want to see something out of the ordinary.

Now we can’t talk about any ash tree without mentioning Emerald Ash Borer. The invasive insect that destroys our ash is still around so you will likely not see any pumpkin ash reach their mature height unless they’ve been injected with insecticide. I’ve never seen this species offered by any nurseries nor treated within swamps so when you do come across it, the tree will usually be smaller or stunted back growing time and time again from its stump. Pumpkin ash is shade tolerant and fast growing so the cycle of growth, damage, and regrowth turns our local ash into weird looking shrubs. Young ash still has good tree form until they reach a few inches in diameter when Emerald Ash Borer starts to greatly affect the trees.  

Pumpkin ash in named as such from its swollen trunk at the base that tapers with height kind of like baldcypress which it grows near in the southern part of the country. It is sometimes called swell-butt ash for this reason, but I and many others prefer the less crude pumpkin common name. You can also identify the species from white ash for its location within flooded swamps and fuzz on new shoots. Like other ash trees, the terminal buds resemble a Hershey’s chocolate kiss and branches are in opposite arrangement. If you’re in southeast Michigan and near a swamp, keep an eye out on you next hike for pumpkin ash!