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Garden Calendar for August

Contributor: David C. Zlesak, University of Minnesota Extension Educator

Although most of Minnesota has received some rain recently, we are still well below average for the year.  Continue to water plants as needed.  Containerized plants and recently transplanted trees, shrubs, and herbaceous perennials have limited root volumes from which to draw mo
isture and needed to be checked frequently for their need of supplemental water.  For most situations it is best to water deeply and thoroughly less often than providing frequent shallow water applications that don't penetrate the root zone.


Thumbnail image for Early August is a good time of year to divide bearded iris. David ZlesakAs we enjoy all the bounty of the summer season in our gardens, keep an eye out for pests.  Frequently scouting the garden for pests when we are out enjoying our plants anyways can help us become aware of a problem before it goes out of hand and we can realistically have a chance to effectively intervene.  Pests can include insects, microorganisms (fungi and bacteria), and other wildlife such as rabbits or deer.

Early August is a great time of year to divide and replant bearded Iris and also purchase new plants.  The leaves can be cut back in order to make them look more attractive and reduce some of the water demands and stress on the recent division.  Plants will put out additional roots before winter sets in.  Keep the iris rhizome (swollen stem part that serves as a storage organ for the plant and grows parallel with the surface of the soil) at the soil surface and slightly exposed.  For more on iris, please visit

Careful pruning and traininig of tomatoes helps with light penetration to fruit and ripening. David ZlesakFor indeterminate tomatoes, continue to train the plants and prune out unnecessary side branches to allow more light and energy to be devoted to the maturing the developing fruit.  With the cool summer, tomatoes are developing and ripening slower than in recent years.

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