September 13, 2002

Planting Depth and Spacing of Spring-flowering Bulbs


The array of spring-flowering bulbs includes tulips, daffodils, crocuses, hyacinths, snowdrops, and flowering onions. By planting a variety of spring-flowering bulbs, gardeners can enjoy blooming plants from late March to mid-June.

The tree may not be sick


Conifers such as pine, spruce, fir, and arborvitae shed their oldest (innermost) needles in the fall, a process known as seasonal needle loss or fall needle drop. Samples showing seasonal needle drop are commonly submitted to the Plant Disease Clinic each fall, with concern that the trees are dying.

Strawberry Protection


Strawberries need protection from the cold winter temperatures. If strawberries are left unprotected, temperatures below 20 degrees Fahrenheit may kill the fruit buds and damage the plant's roots and crowns. For every 5 degrees drop in temperature, the damage becomes more severe. Also, alternate freezing and thawing of the soil during the winter may lift unprotected plants out of the soil and also cause damage. Mulch needs to be applied before the temperature drops below 20 degrees Fahrenheit. In central Iowa, early to mid-November is generally a good time to mulch strawberries.

Rust of Turfgrass


Rust on turfgrass has been common this season. Yellow flecks that later turn into orange pustules can appear on bluegrass, fescue, bentgrass, zoyzagrass, and Bermudagrass. Each pustule contains about 50,000 spores of the fungus. When walking through grass with a severe rust infection, white shoes can become orange.