Soil Scales
Rebecca Magron, Horticultural Consultant & Research Associate
Dated - April 11, 2008

At long last, the gardening season is just around the corner and tasks are lining up on gardeners’ to-do lists. Popular items on this list include pre-emergent crabgrass control, pruning roses at bud swell, seeding bare spots in the lawn, and removing winter mulches as the weather warms. Three important to-do list items that have been inquired about at the Rutgers Master Gardener Helpline are having your soil tested, adding organic matter to garden areas, and scouting for potential problems.

Knowing the pH and nutrient content of your soil is critical in maintaining plant health. Having your soil tested is important and can help save residents time and money by telling them what nutrients their soil has, what fertilizer, if any, to use on their plants, how much and when to apply it. Soil tests should be done at least every three years and separate tests should be done for specific types of plantings such as lawns or a vegetable garden. Soil test kits are available for purchase at the Rutgers Cooperative Extension of Hunterdon County office and include instructions for how to take and submit a soil sample to the Rutgers Soil Testing Laboratory.

Annual additions of organic matter should be incorporated into garden areas to improve and maintain good soil structure, which is essential to plant growth. Organic matter may include compost, peat moss or cover crops and has many benefits to garden soil. Improved aeration and drainage, improved soil tilth, better nutrient and water holding capacities, and encouraged microorganisms are some of these benefits. Be sure to check the moisture content of your soil before working in it. “Heavy” soils must be handled with care. They should never be worked when they are too wet or too dry. If a squeezed handful of soil doesn’t break apart under light pressure, it’s too wet. If clods persist, and it feels like flour when crushed, it’s too dry.

This is a good time to take a walk around your garden and landscape to scout for potential problems since certain pests are more visible now that limbs are bare and the weather is more favorable for outdoor strolls. Scales are insect pests that can be visible at this time of year on landscape plants. There are thousands of scale insect species within about a dozen different families. What they have in common is that they do not appear very insect-like. Under magnification, most scales are oval or oblong and usually some variation of white, brown and/or black in color. They have been described as either smooth or corky “bumps” usually on stems or leaves.

Adult scales adhere themselves to the host plant where they feed. Some scales, known as armored scales, have a hard waxy coating and can cause significant damage to landscape trees and shrubs if infestations are severe enough. Soft scales are relatively less damaging and are often associated with sooty mold, a harmless but unsightly fungus that coats branches and foliage where scales are feeding. Correct identification of the scale species is important when considering control options. If you suspect you have scale in your landscape, bring a sample to the Rutgers Master Gardener Helpline for identification.

Some residents are also calling about bagworm. Look for “cones” at the ends of branches of needled evergreens – especially arborvitae and juniper. Bagworms can infest deciduous plants as well. Cone-like structures, about 1 1/2 to 2 inches long, hanging from the twigs of deciduous plants is a sure sign of this caterpillar that feeds on foliage from mid-June through early August.

Identification, information and recommendations about many insect pests are available through Rutgers New Jersey Agricultural Experiment Station, Cooperative Extension of Hunterdon County, Master Gardener Helpline. The Helpline is open Monday through Friday 9 am to 12 pm and Monday and Wednesday afternoons from 12:30 pm to 3:30 pm. The office is located at 6 Gaunt Place, Building #2, Lower Level in Flemington. Stop by the office with a plant or insect sample, or call the Helpline at 908-788-1735 during those hours for more information on soil testing, plant pests and all other gardening related questions. You can also email the Master Gardeners at