Dying barberry

Question: Fifteen years or more ago, we had the foundation plantings in the front of the house replaced.  At either side in the front row are yews; between them is a row of red barberries,  chosen for color contrast (variety rosy glow). The very first winter, one barberry died. We have been replacing dead barberries ever since. The two at the ends of the row seem to be fine, but at this point all the barberries between are dead. The last time I replaced one, I dug a very large hole and disposed of the soil and then filled with new topsoil. Made no difference. Nursery staff are unable to help because they are surprised the barberries are dying; they see them as a sturdy plant that can grow in almost any conditions. Should I replace all the barberries with something else? Any ideas on the cause?

responder: Lindsey K. Kerr, MS, MHP (she, her, hers)  Replied April 20, 2023, 12:26 PM EDT
response: Hi William,  This is an interesting problem. Barberry are classified as invasive in several states. The Michigan Department of Natural resources released this fact sheet in 2012. The invasive nature of barberry has only grown worse in the last 10 years. They are typically very hard to kill plants!  That said, I would not recommend replacing the barberry with barberry. Not only because it is invasive, but it does not thrive in this location. Before I can recommend a replacement, we need to figure out why the barberry isn't thriving.  I can see that you have a corrugated pipe running behind the barberry. I can also see a downspout and it looks like a water source/spigot at the corner. Do you know if this garden bed gets flooded by water during parts of the year? Or perhaps it is bone dry? Does it get any irrigation?  How old is the rose in the trellis? Have you had to replace it as well? Do you give the rose special treatment (fertilize it, water it)? I look forward to your response.  Lindsey K. Kerr, MS, MHP (she, her, hers)Consumer Horticulture EducatorMichigan State University Extension33030 Van Born Rd. Wayne, MI. 48184

responder: The Question Asker Replied April 20, 2023, 4:49 PM EDT
response: Dear Lindsey: The pipe running behind the plantings is connected to the downspout and the water is discharged beyond the front corner of the house, well away from the barberry. The bed does not ever have standing water. When the first couple of barberries died, a neighbor who was a landscaper suggested a lack of water. So I got soaker hose and wound it around the base of the various plants. There's a timer on the soaker hose (connected to the spigot you see) and I would set it to water for fifteen or twenty minutes every couple of days. Barberries still died. Last summer, I did not use the soaker and barberries died...There is a sprinkler system for the lawn, also connected to that spigot, but it does not put much water on the bed.There is a tendency for plants close to the house to be dry because the house has a wide overhand at the roof. But that would impact the rose most, and the rose is fine.  It is an older cultivar having been introduced over a century ago, and it may be more hardy than some roses.All the other plants, and the two end barberries, thrive. There's the rose, planted at the same time as all the other plantings, yews to either side of the barberries, and two tall arborvitae placed behind the yews. All are doing well.Let me know  if I can provide something further.Bill WordenOn Thu, Apr 20, 2023 at 12:26 PM Ask Extension <<personal data hidden>> wrote:

responder: Lindsey K. Kerr, MS, MHP (she, her, hers)  Replied April 25, 2023, 12:14 PM EDT
response: Hi Bill, I also suspect lack of water. I am guessing that the two barberry one either end  and the rose have more established root systems and are able to survive on less water than the newer shrubs. Last summer, we had very little rain. Wayne County was in a drought. I can't help but think that the barberries succumbed to lack of water if you weren't running the soaker hose.  If you use the soaker hose again, I recommend that you turn it on for 15-20 minutes and then come back and see how much water has come out. How far did the water spread? Was it a tiny bit of water that stayed in one place? Did it run off to the grass? Are the pores in the hose clogged so no water is coming out by the dead barberries? It could be that the water from the hose is not reaching the roots of the plants. You might need to run the hose for a longer amount of time. Shrubs often do better from deeper, less frequent watering. For example, maybe 2 days a week for 30 minutes, but that is dependent on the soaker hose and how much water it is emitting.  Before you replace the plants, I recommend observing how much rain water the bed gets and observing your soaker hose to see if it is putting out adequate water.  That said, you can train the two living barberry to grow into the space vacated by the dead barberry. By allowing their branches to grow in the direction of the gap and selective pruning, you can have that space filled in a season or two with a nice hedge. That might be easier than trying to replace.  Lindsey K. Kerr, MS, MHP (she, her, hers)Consumer Horticulture EducatorMichigan State University Extension