July 23, 1999

Crabgrass in the Lawn

The warm, wet weather in recent weeks has been ideal for crabgrass. Crabgrass is a warm-season annual grass. Crabgrass seeds germinate from spring to mid-summer. Germination begins when soil temperatures reach 55 to 60Å¡F in the spring. The plants grow rapidly during the summer months and often form dense patches in poorly maintained lawns. There are two species of crabgrass found in Iowa lawns: smooth crabgrass (Digitaria ischaemum) and large crabgrass (Digitaria sanguinalis). Both species have wide leaf blades, a light green color, and prostrate growth habit.

Downy Mildew of Grapes

Fruit showing signs of downy mildew have been arriving in the Plant Disease Clinic. Infected berries are usually brown and wrinkled and are covered with the whitish fungus. The undersides of infected leaves also show fluffy, white to grayish fungal growth. Pale-yellow spots are evident on the upper surface of leaves.

Latin Linguistics - A Useful Tool in Horticulture

One of the most frustrating aspects for new gardeners is the use of Latin in Scientific or Botanical plant names. Believe it or not, botanical names were created by Carl von Linne to make plant names easier. Before Linnaeus (Latinized version of Linne) created the binomial (bi = two and nom = name) system, each plant had several names.

Lots of Millipedes This Year - Again!

Household invasion by several / dozens / hundreds / thousands / millions of millipedes (take your pick) is again a common problem across Iowa. Some background information may be useful.

Millipedes live outdoors in damp areas such as under leaves, needles and dead plant debris, or in cracks and crevices. They feed on damp and decaying vegetable matter and are beneficial as "recyclers" of organic matter. However, they become pests when they migrate into buildings as accidental invaders. They are most active at night and usually hide during the day in cracks and other moist locations.