Ron Kujawski | Garden Journal: Protect your garden from unwanted pests

Bug off! No, not you! I am referring to the bugs, or more accurately, the insect pests that are beginning to bug me. Among these are the tiny flea beetles chewing holes in leaves of my radishes, the cutworms mowing down some recently transplanted seedlings, the greenish-yellow larvae of the viburnum leaf beetle munching on leaves of my cranberrybush viburnum, and the four-lined plant bug dining on my oregano plants. The list goes on but I don't want to ruin your lunch with distasteful details. The question now is: "How do I protect my garden plants from these critters?"

The answer to that question is to have a strategy for managing garden pests. The first step is to simply keep an eye or preferably both eyes on your plants. Examine them often for presence of pests. If you see an insect on plants, be sure that it is truly a pest. Most insects are actually harmless and in some cases are beneficial in terms of aiding pollination or as predators of the pest. Once you determine that an insect is causing serious damage, you have several options for managing the problem. Selecting resistant varieties of plants is a good place to begin. For example, while the cranberrybush viburnum plays host to the viburnum leaf beetle, the doublefile viburnum and leatherleaf viburnum are resistant to the pest.

A second option is to manage the environment where plants are growing. Promoting plant vigor through better soil and nutrient management and weed control are examples. Finally, there is the option of confronting the pests directly. This could involve nothing more than hand-picking the offending pests, or if you raise chickens there's the hen-pecking method, a technique used by George Washington in his vegetable garden. Placing barriers such as paper collars around seedling stems to deter cutworms or floating row covers over cabbages to ward off cabbage moths are other examples of direct confrontation. The last option I'll mention is the application of bio-rational pesticides, defined as pesticides relatively non-toxic to people and with few environmental side-effects. These would include such materials as the biological insecticide, Bt, insecticidal soap and horticultural oil. Even with these environmentally benign insecticides, always read the label on the insecticide product before using!


You may wish that I bug off after reading these suggestions for fun in the garden this week:

- Continue to make successive sowings of carrots, beets, bush beans and leafy greens for harvests continuing into fall. Provide shade for leaf lettuce and spinach by sowing seeds in the shadow of tomatoes or sweet corn or by placing an awning of shade cloth over these veggies. Otherwise, try heat and sun tolerant greens such as mustard, baby kale, chard, Malabar spinach, tat soi, and mizuna. I'm experimenting this year with a supposed heat tolerant lettuce variety called Butterhead Speckles.

- Check the foliage of spring flowering bulbs. When the leaves turn brown, they can be cut back and tossed onto the compost pile.

- Be sure not to leave any of the original potting medium exposed when planting annuals in the garden. The high peat media used by bedding plant growers can act as a wick and dry out the root ball of a seedling plant very quickly. So cover any exposed potting medium with soil or mulch. The same is true when planting perennials that were grown in container mixes of peat or composted bark.

- Plant climbing hydrangea against stone walls or other coarse structures that need the softening effect provided by vines. Climbing hydrangea is a great vine for this area. It is hardy and free of any serious pest problems. Look around for specimens of climbing hydrangea in area landscapes as they are now coming into bloom.

- Prepare to deadhead (remove spent flower heads) annuals through the growing season. This will ensure continued flowering. Some herbaceous perennials that re-bloom after deadheading include; Allwood pinks (Dianthus allwoodii), bellflower (Campanula), beebalm (Monarda), butterfly weed (Asclepias), lavenders, masterwort (Astrantia major), pincushion flower (Scabiosa), Shasta daisies, and yarrows.

- Spray roses with a solution of one tablespoon baking soda in a gallon of water for control of leaf diseases. Add a few drops of mild soap to get better coverage of the solution. Repeat applications every 4 or 5 days through the growing season.

- Reduce the risk of spreading turf grass disease by mowing lawns when the grass is dry. Also, keep mower blades sharp and avoid scalping, that is, using a very low cutting height setting on your mower.


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