Select disease-resistant plants

January 31, 2009|By ROBERT KESSLER

Each year plant scientists test new varieties of plants for disease resistance. By careful plant selection and breeding, these traits can be introduced into plants we grow.

An example of this is the chestnut tree. A century ago, eastern U.S. forests were made up of mostly chestnut trees.

Then a disease was introduced, which wiped out nearly all chestnuts. A few survived and have been used in plant breeding to develop a chestnut that is thought to be resistant to the chestnut blight. This has also happened with the American elm, a once-common tree that was killed off by

Dutch elm disease. You can now buy disease-resistant elms.

This work is important to any gardener because they are able to grow plants that don't need spraying to stay disease free.


Recent introductions include an acorn squash and a phlox, both susceptible to powdery mildew.

Last year, a new phlox called David was named perennial plant of the year by the Perennial Plant Association because of its resistance to powdery mildew. A new acorn squash called Honey Bear is a 2009 All American Selection. It is tolerant to powdery mildew and produces well.

Both of these plants are able to be grown in our area without being sprayed with a fungicide to control powdery mildew.

If you tried to grow pumpkin and squash last year, powdery mildew was a huge problem, and, without spraying, the crop was probably reduced by powdery mildew.

As you look for seeds to purchase this year at garden centers and in catalogs, look for disease resistance.

It is one of the best methods we can use to reduce the usage of pesticides. Using less pesticides benefits our environment and us.

Dry indoor

In winter the air in our home will often get dry. One reason for this is that cold, outside air can seep into our house due to air leaks in our attic and basement and around our doors and windows.

This cold air holds less moisture. And as the cold, dry air seeps into the house, warm, humid air seeps out. We end up with a drier home.

Not only does it make your house drier, it costs you money to heat that cold, infiltrating air.

One cure for this is to seal up those air leaks. On the next windy day, check around your doors and windows. If you can feel air blowing in, then they need to be sealed.

Here are some short-term things you can do to add moisture to your home's air:

· Keep the bathroom door open after a shower to let the humid air flow into the rest of the house.

· Make homemade soup on the stove rather than zapping a prepared soup in the microwave. This requires boiling of water.

· Buy and use a humidifier.

· Place open containers of water in areas of your home (keep out of the reach of your children) to evaporate into the air.

· House plants will give off water in the winter, so they can help.

· Use laundry racks to dry some of your clothes instead of putting them in the dryer. Keep in mind that when you run a dryer - which sucks air from the house into the dryer and then blows it to the outside - air is drawn into your house to replace that air.

· Run your dishwasher through its rinse cycle, then open the door when it starts the dry cycle and let the dishes air dry.

These ideas will put humidity into the air in your home. Some of these tips may help mitigate dry skin and other problems connected to dry air in our homes and apartments.

Bob Kessler specializes in consumer horticulture and energy for Penn State University. He can be reached weekdays at 717-263-9226 or by e-mail at

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