Don't Throw Them Away!

By: Doreen Sage

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According to some written material, the cure for botrytis on lilies is to dig up the bulbs and throw them away.

Do NOT do this!  This is not necessary nor is it a 'cure'.  At this time of the growing season, it is time to take preventative steps so I this disease will not attack your lilies next spring.

Botrytis is a fungus that attacks the above ground parts of lilies as well as many other plants. Botrytis flourishes in cool, moist weather.

The fungus over winters on the diseased leaves and stems that are not removed from the garden in the fall. If plant is not diseased, then the stems may be left to help hold the snow.

In the spring, the fungus then produces spores that are blown by the wind or splashed up on to the new foliage by rain or by, watering.  These spores produce brown spots with'', lighter margins and are darker near the center.  This usually starts at the bottom of the plant and works its way up the stem of leaves.

The bulb does not carry botrytis but the bulb may be less vigorous if the leaves are destroyed early in the growing season.  There are other diseases that attack lilies, so be certain that you look carefully to see what your plant is suffering from.

PREVENTION: must be practiced all growing season.  Plant your bulbs in an area that will have good air circulation.  Divide clumps when growth gets dense and/or when vigor and flower count/size diminish.

In the fall, clean up all dead diseased foliage and stems and destroy.  Burn it, if possible. Do not compost.

In the spring, early spraying is essential when wet, coot weather is forecast.  Spraying is only effective when the foliage if dry.  The spray must cover the undersides of the leaves, as this is where the infection starts.  A simple, but effective spray: one tablespoon of baking soda to one gallon of water with a squirt of dish detergent to act as a wetting agent.  A copper-based spray may also be used but is not very effective once infection has attacked the plant.

For outbreaks, a commercial product containing benomyl is effective.  Again, leaves must be dry and the under sides of the leaves must be sprayed.  Wear protective clothing 'when using any fungicide, insecticide or herbicide.

The best defense against this disease is to make certain that all diseased leaves and stems are removed and destroyed. However, since it is a soil borne disease, the lilies can still be attacked.  Therefore, an early spraying program should be considered essential.                 

Botrytis.....A blight or fungus disease that attacks some dies. Copper Spray & Benlate are used as controls.  Clean cultivation, light and air, burn old stocks and debris in fall are good preventative measures.

Virus... A disease of many plants including lilies; recognized by a mottling and distortion on leaves.  Spread by aphids from infected to healthy plants. Prevention - Control aphids by spraying. Cure -None