Plant pathology is the study of plant disease.

When a plant shows a change of color and starts to yellow or pale, begins to lose leaves, drops buds or blossoms, what is wrong? What is the cause for plant distress? Is it bugged? Is it suffering from too much or too little water? Is there a nutrient deficiency? Is it getting too much or too little sun? Is the soil too rich or too poor? Has there been an injury to the plant or to its roots?

Sounds like a visit to the doctor's office is in order, doesn't it?

One common complaint that is heard frequently concerns the sudden death of seedlings in the greenhouse or in the garden. There are sudden deaths that occur to damping off, and the fungus referred to as gray mold, or botrytis. Both can occur in either location.
Prevention is the best caution. Weeding out unwanted plants, thinning tight growing seedlings (either in the planting tray in the greenhouse or direct sowing in the garden), to increase air flow around tender young plants will lessen the likelihood that adverse things will appear, such as these molds or fungus. Some things do seem to sneak in overnight without warning, such as last year's perfect storm of tomato blight. Conditions leading to that devastating swell were Vermont's extremely wet spring and summer season, imported tomato plants from some southern climate, and the many storms that blew up the east coast.

Ann Hazelrigg of the UVM Agriculture School is a specialist in plant pathology and presented the audience of aspiring Master Gardener's with this information. Most of the commercial growers have greenhouses with roll-up sides or are open-ended and the blight came in on the wind. Although the blight is present in the soils here anyway, it does not winter over. The one precaution regarding blight that Dr. Hazelrigg delivered was to remove any self-starters of potatoes in the garden and to discard them in the garbage (not compost pile), or eat them. If there is active blight on a tuber, it is not likely to harm humans. If in doubt, toss it out.

Chewing and sucking insects take a fair share of the garden's yield and diminish the quality of the plants overall. There are organic pest control agents that can be safely applied to both plants and the harvest. Although Master Gardeners are not allowed to give product recommendation, read the label, utilize good practices and apply only the recommended amount. Application of too much of anything (organic or not) is not good for the plant, the soil, or for the gardener. There are natural repelling plants that can be added in a complementary planting. Marigolds are a pretty addition to the garden and do have some bug repellant qualities and alyssum attracts beneficial insects to the garden. A particularly miserable garden bug found most every year is the cucumber beetle. It spreads a mosaic virus in all cucurbit vines. It can adversely affect tomatoes, peas, asparagus, corn, eggplant, and even celery.

Integrated Pest Management (IPM) is the current guide for the gardener to use because it relates to what is bugging the plants at that particular time in the plant's lifecycle and the lifecycle of the bug. Application of a substance to manage the specific pest at the correct stage of its development is what is required for success. For example, in the adult and egg stage of the Colorado potato beetle, there is little harm to the plant. In the larval stage however, they eat plants around the clock. Application of a chemical will absorb into the fat soft bodies and they will be stopped dead from advancing to the next generation. A broad-spectrum chemical pest killer will eliminate both beneficial insects that aid gardeners (honeybees, parasitic wasps, praying mantis) and the pests, regardless of the rules for IPM. Be careful with all applications. I once received a breezy back drift of my own homemade hot pepper spray right in my face; I sported a two-day burn, although I had avoided worse by wearing protective eyewear at the time. Whew!

Compost, compost tea, and worm castings are the stuff of magic. All three nourish seedlings and transplants and demonstrate some restorative powers for distressed plants. For this writer, the best news about these three last items is that they are most effective and right at hand; therefore, everyone can practice making and utilizing these soil magic additives.

Properly nourished and well cared for plants deliver superior results to the avid gardener. Keep the garden plants weed free, well watered, and well visited. A daily walk through the garden can be restorative to the practitioner and the attention renders an immeasurable boost in the garden yield as well. When I was the best at my craft of gardening, I raked the paths at the end of each day for two reasons. I saw everything in the garden as I ended my day, and as I walked through in the morning to pick off potato bugs to feed to the ducks for breakfast, I looked in the rake marks to see what or who had planted their footprints in my field of beans.