Itching to Garden?

It continues to be cold and snowy in Indianapolis. Mother Nature is taking her time this year. The past three winters gave us winter aconite and other early spring flowers by mid-February. Not this year!

If you want to get out into the garden, maybe it’s time to think about your tall German iris (also called bearded iris). If you haven’t yet, cut back and remove last year’s leaves and any surrounding plant debris. This will help you control two different iris pests.

Iris borers are the larval, or caterpillar, stage of a moth. The adult lays eggs in the iris leaves and debris in late summer. In spring, the eggs hatch. The caterpillar climbs onto new iris leaves, burrows into them, and moves down into the iris rhizome, where it feeds. Eliminating the eggs by gathering and discarding all the old plant debris will go a long way toward controlling this pest. For more information on iris borers see http://www.extension.umn.edu/yardandgarden/ygbriefs/e122irisborer.html.

Another pest that attacks iris is iris leaf spot. This is a fungal disease that infects new leaves and causes spots on the leaves and lack of vigor. Again, you can avoid chemicals by simply cleaning up and discarding the old iris leaves. For more information on iris leaf spot see http://www.ext.vt.edu/pubs/plantdiseasefs/450-600/450-600.html.

Of course, you can always change the plant. Siberian iris are resistant to both of these pests.