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INTRODUCTION

Sharon Thompson is our guest writer this week.  She is a well known South Carolina Garden Writer and Speaker. Her articles appear in several Master Gardener newsletters, The State newspaper, and Lake Murray-Columbia Magazine. She enjoys speaking to Master Gardener groups and Garden Clubs.

Here is what Sharon has to say about herself and her gardening: ''I am a no-spray, composting gardener who has a yard, not a garden. A garden implies some sort of order, but making a plan and sticking with it is almost impossible for me.

Originally from Kentucky, I have been gardening in South Carolina since 1978. Our former house had mature shrubs, big oak trees, and lots of shade. Our new house has small shrubs, big pine trees, and lots of sun. The one constant is red clay soil.

I enjoy growing plants from seeds and cuttings but love the thrill of plant shopping anywhere, any time. I completed the Master Gardener program in 1993 and continue to learn about gardening and experimenting with old and new plants.

I garden with the help of two dogs, two cats and a semi-retired husband who supplies occasional muscle power and frequent opinions.''

In Sharon's article ''Cannas & the Leaf Rollers'', she explains the how, when, and why to stomp out leaf rollers that do the damage.  She photographed those beautiful cannas, below, growing in her garden.

 

CANNAS & THE LEAF ROLLERS

by Sharon Thompson, Garden Writer and Speaker, South Carolina

The second week of June brought the first blooms on my cannas. Can the leaf rollers be far behind?

An old-fashioned selection, 'King Humbert,' was the earliest bloomer with bright orange-red flowers perched atop head-high stalks. The foliage, an unblemished dark green that merged into a burgundy border, had been steadily unfurling since April.

Nearby, canna 'Bengal Tiger', brilliant with yellow and green striped leaves, flaunted mellow orange blooms. ‘Tropicana,' fashionably outfitted in leaf stripes of burgundy, pink and dark green, added another shade of orange blooms. Cannas are not for the faint of heart, color-wise.

The annual visit by leaf rollers can lead to canna heartbreak by mid-summer. Last summer was a spectacular year for cannas: abundant rain brought lush growth but it also brought an onslaught of caterpillars.

Commonly referred to as canna leaf rollers, these caterpillars are the larvae of Brazilian skipper moths. Eggs are laid inside unfurled leaves, whose edges are then bound together with silken threads. The caterpillars emerge into a protected and private dining room then proceed to graze leisurely on the foliage smorgasbord at hand. They leave behind not only the predictable caterpillar poop, but also tattered and bruised leaves.

Leaf-roller control has many options. The best approach is to remove the offending foliage when you see the signs and trash it – literally – in the garbage, not the compost pile. Other suggestions involve unrolling the leaf and squishing the resident caterpillar inside: a hands-on approach I find infinitely satisfying. Dusting or spraying with various chemicals, insecticidal soaps or Bt are also options, but none I choose to do.

Sanitation goes a long way to reducing leaf roller numbers so plan to do a thorough clean up in the fall. This is easier to do before the first frost while the stalks are still firm: Cut the plants to the ground, remove all the foliage and surrounding mulch and dispose of it in the garbage. That should eliminate most of the caterpillar eggs that could over-winter in the old leaves and stalks. If yours is a harsh winter area, dig the canna bulbs after you have removed the foliage.

The good news is that the caterpillars' presence does not affect the flowers. These flashy beacons send a nectar signal to the local hummingbird crowd who zip in and out of the towering stalks occasionally stopping for a quick snack.

After last year's leaf-roller infestation, I vowed total removal of the plants if the situation got that bad again. But that is an empty threat, for what can be easier to grow than a canna: full sun, adequate moisture and a bit of fertilizer in the spring. The foliage of most perennials adds a fine texture to the garden, so the bold foliage of cannas is a welcome change of pace.

Breeders have been hard at work, resurrecting old varieties and hybridizing new ones, presenting the gardener with countless color combinations of foliage and flower and an assortment of heights from under three feet to over eight. One of the most spectacular is canna 'Australia' whose glossy burgundy leaves and scarlet blooms add a ''Wow!'' factor to the garden.

When the leaf rollers arrive this year, I will probably resort to my customary squish-and-prune control methods. If the foliage gets too unsightly, I plan to try a new tactic:  whacking the plants completely to the ground, showering them with water and fertilizer, then enjoying lush foliage and fresh flowers for summer's shift into fall.


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