Marin IJ Articles
March 11, 2017
As American author and editor Barbara Winkler said, “every gardener knows that under the cloak of winter lies a miracle ... a seed waiting to sprout, a bulb opening to the light, a bud straining to unfurl. And the anticipation nurtures our dream.”
To encourage that dream garden, experienced gardeners recommend an integrated disease management program focusing on exclusion, eradication, protection and resistance. Create a healthy environment for the plants in your garden by incorporating seven practices to promote vigorously growing, healthy plants.
Maintain a cleanliness program in the garden. Start with a clean planting site free of last year’s plant debris. In most cases, plant parts should be removed as soon as you see a plant is diseased or dead. Raking leaves, removing dead fruit or flowers or branches, diseased leaves, dying plant parts or digging up diseased plants (including the roots) are all examples of sanitation. The dead plant material often contains bacterial, fungal or even viral pathogens that can overwinter in the soil and re-emerge in the spring. Protect the soil and monitor or amend it so potential problems are exposed and any pests dwelling there are destroyed.
Weeds can be a source of plant pathogens so controlling weeds is essential. Weeds can serve as hosts to pests that can move to the desirable plants in your garden. Keeping areas that border the garden mowed and trimmed is one method of controlling the potential problems that weeds impose. It is not recommended that diseased plant material or weed debris be composted because the heat generated by the compost may not reach temperatures hot enough to kill the weed seeds or all of the disease organisms. Weeds should be buried or removed in green waste.
Disinfect tools, pots and equipment after use to prevent plant pathogens from spreading to other plants.
To disinfect dip tools into a 10 percent bleach solution (1 part bleach to nine parts water) and then allow the disinfected items to dry.
MONITOR FOR DISEASE
Examine plants in and around the garden at least twice weekly throughout the growing season, focusing on a few plants of each cultivar. Search under leaves, inside developing fruit, along stems, and at the plant base or crown. Note signs and symptoms of feeding damage, insect excrement, holes in leaves or fruit, and twisted or deformed leaves. Record the extent of the damage from week to week to aid in determining whether pest damage or disease symptoms are increasing. Devices such as traps and row covers are useful to control and monitor pest infestations.
Select plants with healthy looking leaves and strong stems. Plant recommended cultivars and maintain fertile soil with proper pH and moisture to provide your garden a means to outgrow pest damage. When possible, choose resistant cultivars, preferably those that attract beneficial insects. Plant the right plant in the right microclimate for it to thrive.
Promote plant vigor. Avoid overwatering or planting in poorly drained soil to prevent root disease and seed decay. Space plants for good air circulation and plant in well-drained soil. Top dressing the soil with organic matter can improve garden beds with poorly drained soil. Water in the morning so upper plant parts dry off. Don’t apply water to the trunk of trees — direct water to the drip line of the canopy. Avoid splashing water up onto the leaves. Avoid growing the same or related crops in the same garden area for successive seasons.
Apply mulch around plants to keep disease spores from splashing from soil onto foliage. Be sure to keep mulch away from stem bases and tree trunks and clear of the root flare.
We can all agree with theologian David Wheeler who once said “gardening is about cheating, about persuading unlikely plants to survive in unlikely places, and when that trick is well accomplished, the results can be highly satisfying.”