Bucks County Herald

Elizabeth Ludlow Bowman: Tips for the Compleat Gardener

Irises to consider

A clump of bearded iris showing signs of a borer’s habitation.

Evening is gently falling around me and I realize we are days away from the Summer Solstice, an event I have experienced from several directions as I have moved towards maturity.

I have been in magical gatherings with friends in the 60s, in theater and now the realization that at the Solstice the days start getting shorter, nights longer, winter is coming.

At this point of my life as a professional gardener winter is a time for designing and writing so I don’t mind the turn of the tide at the peak of the longest day of 2017, June 21, summer begins.

Today we were regarding the pictured clump of bearded iris and thought it must be under attack by borers so we dug it up, cut the blades back to about 5 inches long and cut off any rot, ready to stab any borer.

A borer is a flesh-colored caterpillar that one might find in the rhizome, having bored through with its mouth parts (think of that). These irises were actually healthy but severely over-crowded so we forked them out and kept nice clumps of each kind aside while loosening the soil and replanting in the refreshed soil.

You will find if you treat the clumps of rhizomes gently they will fall naturally into individual pieces perfect for planting. Cut the leaves to 5 inches, shake soil off the roots then lay the brown and rooted rhizome sideways on the soil then dig the roots in by digging away the soil to let the roots fall naturally down. Re-cover the roots leaving the top half of the rhizome above the soil, exposed. By the time we had separated the crowded bearded iris there were plenty of nice rhizomes to plant, leaving space on all sides between the other clumps.

We were forced to look around the larger garden for bare spaces where an iris might fit and I planted several clumps of three rhizomes. We like to suggest to the homeowner that she might have friends who would like some iris, if not I sometimes give them to the iris farm in West Amwell.

I have iris here and there at my own house and this year was a spectacular year for bearded iris. I know the Siberian iris are about to bloom and we will see what their show is for 2017. For the best clumps of iris separate the clump at least every three years.

If you do have borers expect to see brown lines running down the leaves getting larger as they move down towards the rhizome, growing from larvae to a hairless, flesh-colored caterpillar in the rhizome.

The gardener needs to cut off the progress of the transformation even if it means stabbing the worm in the root. Often cutting the leaf at the bottom of the brown trail also cuts the intruder, some people have trouble with larva liquidation, as it were, without chemicals.

Your bearded iris will thank you for the trouble. Dispose of infested leaves in the trash instead of composting.

Keeping the iris bed clean removes the debris in which the original borer eggs were laid, one of the best methods of preventing borers.

A couple of other tips: to prevent powdery mildew you can spray the often affected plants with a solution of nine parts water to one part skim milk in the morning every other day, starting before mildew arrives.

The gardener can do the same with a solution of one teaspoon baking soda to one quart of water spraying every day. Try to buy mildew-resistant cultivars of your favorite perennials. Wash your tools and your hands often.

Enjoy the moment.




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