By Bill Kleiman
On a recent blogpost I mentioned that I mowed a gray dogwood patch, Cornus racemosa, in about 1994, so 3 decades back. I only mowed it one time with a rotary mower on the back of a tractor. The dogwood clone had stalks about six feet tall. Since then we have been frequently burning this unit to keep various brush in check. It appears that those fires kept top killing the dogwood where it would re-sprout again as is shows in these current photos.
If we had time on our hands, we could treat each stem with basal bark herbicide but this low patch seems ok to me, with various grasses and forbs intermixing with it.
grassland restoration network 
I have often wondered about the give and take of things like dogwood and hazelnut under historic fire management by the original inhabitants. In a huge prairie landscape interspersed with savanna and open woodlands, prairie “thickets” might have been fairly common and even desirable. We don’t have that much space these days, even on a fairly large property like Nachusa!!
Your long term observations are very helpful. How often do you estimate this unit is burned? This gives me hope I may be able to ignore scattered, small diameter dogwood as long as regular burning takes place. I’m guessing the formation of dense, large diameter clones is caused almost exclusively by infrequent or no fire? Paul makes a good point that the decision to control dogwood may depend on site size.
Ignoring small dogwoods is appealing because herbiciding lots of small stems is labor intensive & risks damage to native vegetation or the soil microbiome for foliar application or if precipitation occurs within 4 or so days of basal application. At my site, my superficial observation after dormant season treatment of a mature dogwood clone (5’ max height) is that meticulous cut stump application of 20% Garlon 4 in bark oil to every stem resulted in few root resprouts in the center of the clone, but many resprouts farther away from the center. My theory is that densely packed, large diameter stumps at the clone center absorbed enough herbicide to kill the root, while more widely scattered, small diameter stumps at the clone edges didn’t absorb enough herbicide. Applications in areas with scattered small diameter dogwood resulted in lots of root resprouts the next growing season.
Fire return interval is about 1.4 years
We’ve been experimenting with a mid-summer brushhog treatment of dogwood with a late august/early September fire on the regrowth at a low point for reserves. Initial results are promising. Unmowed dogwood immediately resprouted post fire, summer mowed clones had pretty severe mortality. Will see what rebounds in the next growing season. Salvia was blooming in the unit 6 weeks after the fire.