June 2021: A Change in the Weather: Modifying Garden Microclimate to Improve Plant Health

Windy Cloud IconAs plants in your garden grow and fill in,  wet and humid conditions will arise that are perfect for diseases to develop.  Follow the tips below to prevent diseases in your garden by opening up air flow, reducing humidity and keeping leaves dry.

Leave plenty of space between new transplants

Think ahead to how big plants will be when full-size, and leave enough space so that foliage on adjacent plants won’t overlap when plants are fully grown.

Divide perennials

Plants like peonies and daylilies grow in clumps that can get quite large, and leaf disease problems tend to increase with clump size.  So, divide clumps to yield smaller plants that trap less moist air.  Dividing and replanting will also allow you to correct existing spacing problems.

Thin plants judiciously as they get big

Remove enough leaves and stems to promote good air flow, but not so many that the plants look thin and lanky.

Weed, weed, weed

Ornamentals aren’t the only plants that trap moist air; weeds can do this, too.  Removing weeds routinely can reduce the need to thin the ornamentals that you really want in your garden.

Water from below

Even though Mother Nature supplies water from above in the form of rain, when you need to water, apply water to the soil, rather than over the tops of plants.  Keep leaves dry whenever possible.

Modifying the environment in your garden can help prevent diseases like powdery mildew, shown here on phlox.
Modifying the environment in your garden can help prevent diseases like powdery mildew, shown here on phlox.

With just a little effort, you can create a microclimate in your garden that is less favorable for plant diseases and end up with more vibrant, beautiful, and healthy plants.

Need more information?

For more information on specific plant diseases and their management, check out the fact sheet section of the UW-Madison PDDC website (https://pddc.wisc.edu/fact-sheet-listing-all/).