Leave Leafcutter Bees Alone
Semicircular holes chewed from rose leaves are caused by beneficial leafcutter bees. They use the leaf sections to construct nests for egg-laying. Leaves are rolled into tubes and stuffed between wood siding, fences, or into the soil. Leafcutter bees are among nature's best pollinators so no controls are recommended. If you desire preventive control, consider the use of a floating row cover over roses to exclude the bees from the rose foliage.
Be on the alert for early attacks by the geranium budworm. Geraniums, petunias, and nicotiana flowers and buds can quickly be devoured by these tiny caterpillars. The caterpillars will often take on the color of the flowers they are eating, which makes them difficult to find. Handpick or use the biological control Bt (Bacillus thuringiensis) -- sold under various trade names. It is very effective in controlling young caterpillars but is harmless to other creatures.
You can propagate bleeding hearts (Dicentra) when growth has stopped and foliage has disappeared. The plant is dormant at this stage so you can safely dig up the root mass and cut it into 2-inch pieces. Plant root pieces in a mixture of sand and rich garden loam. Keep the soil moist and new shoots will appear. Move the new plants to their permanent location in the spring.
Check Vegetables for Pests
Inspect your tomatoes and peppers for psyllids. These tiny, slow-moving insects can be found lurking on the stems and undersides of the leaves. The immature forms are tiny, disc-like greenish nymphs attached to the undersides of the leaves. They cause yellowing and inward rolling of the leaves. Droppings from these pests appear as a coating of sugar. Homemade soap sprays and sulfur dust applied every three days can control psyllids. BUt don't use sulfur when temperatures are above 80 degrees.
Prevent Corn Earworms
After corn silks emerge 3 to 4 inches from the corn ear, squirt vegetable oil into the tip of the ear. This will discourage adult moths from laying eggs on the corn tips and will smother larvae trying to enter the ear. Don't coat the ends of the silks or you'll interfere with pollination.