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Pest and Disease Control for Perennials and Roses

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Before considering any type of pest management, it is critical to identify the pest or disease before trying to treat it. Often times solutions exist that can control the pest or disease with simple environmental changes. Easy changes in watering schedule or application can affect plant health. To be sure that you are treating your plant correctly, we recommend you bring a piece of the affected plant in to one of our trained professionals.

Always read the label on any product you use on your garden for specific pests, time of application and particular warnings.

One last consideration, pesticides are not selective and will kill off the beneficial bugs in your garden. By managing pest control wisely and treating for damaging insects and diseases only when necessary, your garden will reward you with beautiful results.

Many of the insecticides suggested here have an all-purpose solution or all-in-1 solution like Triple Action. However, there are many insects that can be controlled more effectively by using a specific insecticide.
Below are some tips and suggestions you can use when dealing with garden problems.

If you have any questions or concerns about certain insect or how to use a chemical please contact us and we will be happy to help you with your gardening needs.

  • Select the insecticide that will control the insects which are a problem. For most home gardens, dust formulations are more convenient to use than liquid concentrations.
  • Read the label before applying the insecticide to determine the correct amount and the proper method of applying the material.
  • Most insecticides do not perform efficiently at temperatures below 50 degrees F and will not give satisfactory results at these lower temperatures. Rain within a few hours after application will wash off much insecticide and make it ineffective.
    For the most part, it is best to apply an insecticide when the temperature is above 50 degrees F but below 95 degrees F and there is no rain expected for at least 12 hours.
  • Apply the insecticide at the proper time for better control of insects. Early treatment affords better protection of plants and prevents insects from multiplying.
  • Make thorough treatments, especially on the lower parts of plants and the undersides of leaves.

Herbaceous Perennials-plants without woody growth

Aphids – Clusters of tiny pear shaped insects on stems and leaf petiole
Organic Control: Wash off with hose, homemade garlic spray or hot pepper spray
Biologic Control: Ladybird Beetles (Lady Bug)
Insecticide: Horticulture Oil, Neem Oil, Fertilome’s Triple Action Plus
Insecticidal Soap: Safer Soap

Mealybug – White, cottony masses of insects, often secrete honeydew
Organic Control: Wash off with hose
Biologic Control: Ladybird Beetles (Lady Bug), Praying Mantis, Lacewings
Insecticide: Horticulture Oil, Neem Oil, Fertilome’s Triple Action Plus
Insecticidal Soap: Safer Soap

Scale – Oval shaped insects, some armored, often secrete honeydew
Organic Control: Pick or scrub off or remove with cotton swab dipped in alcohol.
Biologic Control: Ladybird Beetles, (Lady Bug), parasitic wasps
Insecticide: Fertilome’s Scalecide & Dormant Oil
Insecticidal Soap: Safer Soap when in crawler stage, not effective on adults

Slugs & Snails – grey or tan & slimy
Organic Control: Wash off with hose, add organic mulch to encourage predatory mites.
Biologic Control: Green and brown lacewings, predatory mites
Insecticide: Fertilome’s Triple Action Plus, Fertilome’s Rose, Flower & Vegetable Spray
Insecticidal Soap: Safer Soaprepeat weekly until infestation controlled

Spider Mites – dot sized spiders on underside of yellowing leaves, webbing
Organic Control: Wash off with hose, add organic mulch to encourage predatory mites.
Biologic Control: Green and brown lacewings, predatory mites
Insecticide: Fertilome’s Triple Action Plus, Fertilome’s Rose, Flower & Vegetable Spray
Insecticidal Soap: Safer Soaprepeat weekly until infestation controlled

Thrips – Very tiny oblong shaped insects in buds, petals
Organic Control: Yellow Sticky Traps, Strong spray of water repeated 3 days
Biologic Control: Green and brown lacewings, Ladybird Beetles (Lady Bug)
Insecticide: Fertilome’s Triple Action Plus RTU, Neem Oil
Insecticidal Soap: Safer Soaprepeat weekly until infestation controlled

Roses

Aphids – Clusters of tiny pear shaped insects on stems and leaf petiole, deformed growth
Organic Control: Strong spray of water repeated 3 days, homemade garlic spray or mix ½ water & ½ Listerine & spray
Biologic Control: Ladybird Beetles (Lady Bug), Lacewing larvae
Insecticide: Fertilome’s Systemic Insecticide Granules, Dormant Spray and Summer Oil Spray
Insecticidal Soap: Safer Soaprepeat weekly until infestation controlled

Cane Borers – Larvae of Sawflies makes a small hole in rose cane
Organic Control: Observation & removal of canes with damage, place a small bit of glue over newly pruned canes to prevent
Biologic Control: Dust with Bacillus thuringiensis (BT)
Insecticide: Fertilome’s Systemic Insecticide Granules, Rose Defense
Insecticidal Soap: Not effective on burrowed larvae

Rose Scale – Oval shaped insects, some armored, often secrete honeydew
Organic Control: Consistently prune rose to remove infested canes
Biologic Control: Some beetles and parasitic wasps-not effective on adult population. Best remedy prune and spray with Dormant Oil in late winter
Insecticide: Fertilome’s Scalecide & Dormant Oil, Bayer Advanced Garden Rose & Insect Killer
Insecticidal Soap: Safer Soap when in crawler stage, not effective on adults due to armor

Spider Mites – dot sized spiders on underside of yellowing leaves, webbing
Organic Control: Wash off with hose 2-3 times weekly-plants stressed by drought are more tasty to mites
Biologic Control: Green and brown lacewings, predatory mites
Insecticide: Horticulture Oil, Neem Oil, Bayer Advanced Garden 2 in 1 Rose & Flower
Insecticidal Soap: Safer Soaprepeat weekly until infestation controlled

Thrips – Very tiny oblong shaped insects in buds or petals, bud dies and drops
Organic Control: Yellow Sticky Traps, Strong spray of water repeated 3 days
Biologic Control: Green and brown lacewings, Ladybird Beetles (Lady Bug)
Insecticide: Bayer Advanced Garden 2 in 1 Rose & Flower Concentrate
Insecticidal Soap: Safer Soaprepeat weekly until infestation controlled

Plant Diseases

Black Spot – Black spots on leaf caused by fungus
Organic Control: Increase air circulation by pruning, water early in the day, water at root level
Fungicide: Add Baking Soda to Horticultural Oil1 Tbs of each to 1 Gal. water
Pesticide: Neem Oil
Preventative: Wilt Pruf acts as an anti-transpirant prevents spores from entering plant

Powdery Mildew – White, powdery-like coating on plant parts caused by fungus
Organic Control: Increase air circulation by pruning, water early in the day, spray with baking soda, or a mixture of 20% skim milk with water
Fungicide: Add Baking Soda to Horticultural Oil1 Tbs of each to 1 Gal. water
Pesticide: Neem Oil
Preventative: Wilt Pruf acts as an anti-transpirant prevents spores from entering plant

Rust – Rust colored spots on underside of leaf, easily wiped off, caused by fungus
Organic Control: Pick off and destroy infected leaves, increase air circulation by pruning, wate
Fungicide: Bayer Advanced All in One Rose and Flower Concentrate, Fertilome’s Systemic Fungicide
Pesticide: Neem Oil
Preventative: Wilt Pruf acts as an anti-transpirant prevents spores from entering plant

Information gathered from Cooperative Extension Service, Organic Gardening Magazine, Bayer Advanced, Fertilome, Growing Roses the Natural Way by Mark Whitelaw and Backyard Gardener.com.

The term R.E.I means restricted entry interval- this is the recommended time that should pass before working around or harvesting any plant that has been treated with a pesticide. The products mentioned in this handout have R.E.I’s of less than 12 hours. Please Always read the label before using any product.

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