Follow these rules carefully and spray once in early May and again in late August or early September:

• 1T Mild dishwashing liquid (e.g. Palmolive green)
• 2T Ultrafine horticultural oil (e.g. Sunspray)
• 1T Baking soda (e.g. Arm & hammer)
• 1T 8-8-8 seaweed/fish oil emulsion (containing no sulfur)

Mix these ingredients, one at a time and in the order listed, into one gallon of water, stirring well after each addition. If any chewing caterpillars have been seen, also add the label-recommended amount of BT (bacillus thuringiensis) as an extra ingredient.

Now for the rules:

• Water the roses thoroughly in the morning, including the foliage.
• Never use seaweed/fish oil emulsion that contains sulfur. It will act adversely with the horticultural oil and damage foliage. Follow the label instructions.
• Always use a fine-mist or pump-up sprayer, never a hose-end sprayer.
• Wet all foliage thoroughly on both sides.
• Spray only in the late evening so that the oil will dry overnight.
• Always make sure that the spray dries before sunlight hits it; otherwise there will be leaf damage.

As an extra bonus, infrequent use of this spray (and only this spray) will encourage the return of beneficial insects. It has also been found that planting garlic chives around roses will keep red spider mites and aphids away.