Pesky Problems You Might Encounter When Growing Joe Pye Weed

Joe Pye weed (Eutrochium spp.) is a must-have plant for North American native plant and rain gardens. While this tough perennial is a relatively low-maintenance plant, it isn't entirely problem free. Powdery mildew and scorched leaves are two of the most common problems Joe Pye weed is susceptible to.

Hardy in zones 4 through 8, Joe Pye weed can be a surprisingly aggressive spreader, thanks to both its rhizomes and its seeds. This can be viewed as either a positive or negative trait depending on how much space you have for your plants and whether you have any friends or family who would like some Joe Pye weed for their own garden. Regardless of how you deal with your extra plants, it is important that you prevent your Joe Pye weed from getting too crowded, as this can quickly lead to insufficient airflow which can often result powdery mildew.

Plenty of sunlight and good air circulation are the two most important factors for preventing powdery mildew in your Joe Pye weed. While Joe Pye weed can grow in either full or part sun, increased shade tends to result in increased powdery mildew as the mildew spores are often killed by direct sunlight. While there are a variety of hacks for getting rid of powdery mildew, it's best to prevent it from getting a foothold in your garden in the first place by giving your plants plenty of sunlight and good air circulation.

Spacing your Joe Pye weed plants around 3 feet apart and weeding out any unwanted seedlings should ensure sufficient airflow and limit powdery mildew. In addition to planting your Joe Pye weed in a sunny area and keeping an eye out for overcrowding, you can also opt for Joe Pye weed cultivars that have powdery mildew resistance. Many of these cultivars have the advantage of being smaller as well, often reaching only 4 feet tall or less, instead of the 8 to 12 feet that some varieties of Joe Pye weed can reach. 

Joe Pye weed can be susceptible to leaf scorch during hot weather if it is not receiving enough water. While Joe Pye weed can happily grow in loam, silt, or clay soil, the growing medium needs to remain moist for the plant to thrive. If you are thoughtful about where to plant your Joe Pye weed and choose a location where it receives plenty of hydration, like a rain garden, leaf scorch should rarely be an issue.

If you do start to notice scorching on your Joe Pye weed's leaves, increase how often and how deeply you water it. You should also consider adding garden mulch to help prevent water loss from evaporation, which should allow your Joe Pye weed to thrive, even during a heat wave. You can also try using ollas or irrigation globes in the garden to ensure the growing medium won't dry out.