July 28, 1993

Let's Talk About Hybrids and Standards

Numerous plant seed choices are available to choose from each year at garden centers and from mail order sources. Of these selections, many are hybrids others are standard (open pollinated) varieties. What benefits are there to growing hybrid vs standard varieties? How are hybrids created? An article written by the National Garden Bureau answers these and other seed questions very well.

Plant Disease Clinic--Highlights

Bacterial Blight - Geranium

Rainy weather has favored the development of foliar diseases on flowering plants. Bacterial blight on geraniums is an example. The spread of this disease and its symptoms are usually most severe under rainy, hot weather.

The Apple Scab Epidemic of 1993

Without a doubt, 1993 has been the worst year for apple scab on apples in over a decade. Some orchards nearly 100% fruit injury in susceptible blocks. How did we get into this mess? Here are some of the contributing reasons:

Too much rain. You already knew that, didn't you? Scab thrives on prolonged rainy spells in spring and summer. Rain has prevented many growers from getting into their orchards in a timely way, and has washed off part or all of fungicide sprays prematurely. As a result, the leaves and fruit have been unprotected for extended periods.

Crabgrass Control

Crabgrass is showing up frequently in lawns at this time. Crabgrass is a warm season annual weed that germinates when soil temperatures reach 55 to 60 F. and thrives throughout the summer if not controlled. Two species of crabgrass are commonly found in Iowa lawns, smooth crabgrass (Digitaria ischaemum) and large crabgrass (Digitaria sanguinalis). Both plants have light green foliage color and prostrate growth habit. Seedheads, which look like finger-like projections, begin appearing in late summer and continue until frost.

Harvesting and Drying Everlasting Flowers

Everlasting flowers are not the perennial flowers or weeds in your garden that you just can't seem to get rid of. They are flowers that retain their color and form when dried. Many everlasting flowers are composed of colorful, papery petals called bracts that are stiff and dry while still attached to the living plant. The French call them "immortelles." Flowers of this type are popular to grow and save for winter arrangements.

Garden Sanitation

Gardeners have realized the limitations of fungicides and insecticides this growing season. Continuous rainfall has made it almost impossible to apply protective products for preventive control. In many cases, the products aren't on the plant for even 24 hours. As plants and produce succumb to what mother nature is dishing out, cleanup of infected and infested plant materials is very important. All diseases and insects have some survival structure which enables them to live until the next growing season or until a susceptible host is grown.