Summer Solutions for the Things that Bug You
Posted by Jessie Jacobson on Jul 12th 2026
Summer Solutions for the Things that Bug You
In any garden, it is inevitable to have an unwanted visitor or two from time to time. While some insect feeding is to be expected, sometimes feeding can begin to threaten the health of plants in the garden and may require some form of intervention.
Before beginning any treatment, it is important to identify the pest of concern to ensure it is appropriately managed, and to avoid trying unnecessary or ineffective treatments. Always keep in mind the other beneficial insects and pollinators that share your garden space, accept a certain level of insect damage in your garden as part of its role in the natural environment, and exhaust less intensive and nonchemical means of control before considering further treatment.
Identifying Pests
Signs and Symptoms
Presence of honeydew: a sticky, shiny waste secretion on leaf surfaces where aphids are feeding, usually accompanied by twisted and curled leaves and disfigured young growth.
Management and Treatment
Aphids are generally more of a cosmetic issue than a plant health concern. Spraying off plants with a strong stream of water to remove aphids and wash off honeydew is usually sufficient. New growth tips or blooms can also be removed to significantly reduce populations. For severe infections, judicious application of insecticidal soap or horticultural oil can help, but is rarely necessary.
Commonly Affected Perennials
Salix (Willow), Sedum (Stonecrop), Brunnera (Siberian Bugloss), Heliopsis (False Sunflower), Asclepias (Milkweed)
Japanese Beetles
An invasive species of beetle in the United States, 1/3” to 1/2” long with a metallic green head and thorax and metallic copper-brown wing covers. Feeds on the leaves, flowers, and fruit of over 300 plant species. Population numbers fluctuate from year to year, with beetles feeding for six to eight weeks beginning in mid to late June. Adults can fly up to several miles between feedings and are most actively feeding in July and August. Damaged leaves emit feeding-induced odors which attract other beetles, as do their potent pheromones, often resulting in large clusters of beetles on some plants while neighboring plants are only lightly infested. Read more from the U of MN Extension here.
Signs and Symptoms
Skeletonized leaves with intact veins, holes in flower petals, stunted plant growth, clusters of brown, dry patches on leaves.
Management and Treatment
A cup of warm soapy water can be used to drop large populations of beetles in by hand, holding the cup just under the beetles as they will drop down before flying, or colonies can sometimes be dispersed with a strong stream of water. Particularly high value or tender plants may need to be covered in netting to prevent extensive damage. Beetle pheromone traps are not recommended for small yards.
Commonly Affected Perennials
Rosa (Rose), Hibiscus (Hardy Hibiscus), Alcea (Hollyhock), Hydrangea, Malus (Apple/Crabapple)
Two-Spotted Spider Mite
A small arachnid pest that uses piercing-sucking mouthparts to feed on plant phloem on the undersides of leaves. Spider mites are at their most active in especially hot (over 90F) and dry conditions, able to cause extensive damage, especially when plants are stressed (e.g., drought). Spider mites colonize the undersides of leaves and produce webbing along the leaf surface where they nest and feed. Read more from the U of MN Extension here.
Signs and Symptoms
Very small, slender, yellow-orange pests present in large numbers, often alongside very fine webbing on the undersides of leaves. Feeding causes white or yellow mottling on leaves, and eventually yellowing leaves and leaf drop.
Management and Treatment
Avoiding stress is one of the best ways to help manage spider mites, especially through consistent watering in times of drought. If infestations begin to impact plant health and vigor, targeted applications of insecticidal soap or horticultural oil can help to manage populations.
Commonly Affected Perennials
Hemerocallis (Daylily), Penstemon (Beardtongue), Salvia (Meadow Sage), Scabiosa (Pincushion Flower), Weigela
When applying pesticides, it is best practice to do so in the early morning or late evening, when our pollinator friends are less active. Pesticides should never be applied directly to flowers' blooms.
Application should also be avoided on plants nearby water sources (lakeshores, ponds, etc.) and storm drains to avoid contaminating groundwater and harming aquatic invertebrates.
Always read the directions on your pesticide's label and follow them accordingly - it's the law!
Pest Solutions
Captain Jack's Deadbug Brew is approved for organic gardening to control a wide range of insect pests including bagworms, leaf borers, beetles, caterpillars, leaf miners, spider mites, and thrips. Use on listed vegetables, citrus, fruits, annuals, and perennials.
- The active ingredient, Spinosad is a substance made by soil bacterium that can be toxic to insects. Spinosad works to kill insects that eat treated plants or that make contact with treated plants. Spinosad is highly toxic to bees and beneficial insects when wet, but has little to no effect on them after it has dried (after around 3 hours). Read more from the National Pesticide Information Center here.
Bonide's All Seasons Horticultural Spray Oil is approved for organic gardening to control a range of insect pests including adelgids, aphids, scale insects, mites, mealybugs, and certain species of moths. It contains mineral oil and functions as both an insecticide, fungicide, and miticide. Similarly to Captain Jack's Deadbug Brew, All Seasons Horticultural Oil is harmful to bees and pollinators when wet - but when dry is not.
- As an insecticide and miticide, horticultural oil covers the insect and causes suffocation. This mode of action is effective on the egg, larval, and nymph stages. Total coverage of the pest must be made for the oil to be effective.
- As a fungicide, this product will work in two ways: It reduces the population of vector insects (a vector insect transmits disease to plant tissue while feeding) like psyllids and leafhoppers, and it will interfere with the fungal pathogens ability to attach to plant surfaces.
- Horticultural oil can be used year-round, in both the dormant and growing seasons. Use on ornamentals, roses, indoor plants, vegetables, and herbs up to the day of harvest.
Sluggo & Sluggo Plus are our go to solution for slugs and snails, which are the bane of the hosta garden. Sluggo's active ingredient is iron phosphate, which occurs naturally in soil, along with snail and slug bait attractants in the form of wheat gluten. The bait not ingested by snails and slugs will degrade and become a part of the soil. Sluggo remains effective even after rain.
- Sluggo Plus combines iron phosphate and Spinosad which is toxic to a variety of garden pests including slugs, snails, pillbugs, cutworms, sowbugs, and earwigs. Sluggo Plus is toxic to aquatic invertabrates, so extra caution and care should be taken when applied to plants near sources of water like lakeshores or ponds.
- Sluggo is most effective if used in early Spring when the baby slugs first appear from eggs that have overwintered over in the soil. When you see the first leaves popping up in the garden, it’s time to treat the area. Make a second application 1 month later, and then again in early August. With this approach you will short circuit the three to five generations of slugs that appear every season while. Sluggo works best when soil is moist but with little or no standing water.
Insecticidal Super Soap is a fast-acting insecticide that is effective in controlling over 30 types of insect pests and mites on vegetables, fruits, herbs, annuals, perennials, and foliage plants. Its active ingredients are Potassium Salts of Fatty Acids, and Spinosad. It is suitable for Organic gardening.
- This product kills insects and mites through direct contact and ingestion. Direct contact with piercing and sucking insects such as aphids is most effective, while leaf eaters like worms and caterpillars make contact through ingestion. Insecticidal Super Soap is harmful to bees and pollinators when wet - but when dry is not.
- Insecticidal soap can also be used a fungicide and is an effective treatment for powdery mildew. It is approved only for outdoor use. Insecticidal Soap, without the "super" is a great tool for use on indoor plants!
Neem Oil is kind of the cure all as an all-purpose insecticide, miticide, and fungicide that can be used for organic gardening. Derived from the Neem seed, use on roses, flowers, vegetables, herbs, annuals, perennials, indoor plants, trees, and shrubs.
- Neem oil kills all life stages of insects including hard-to-target eggs and larvae. Also effective in treating fungal infections such as black spot, powdery mildew, and rust. Neem oil is generally non-toxic to birds, mammals, bees, and plants. However, this product is toxic to bees exposed to direct treatment, and moderately toxic to fish and other aquatic animals. Care should be taken when sprayed to avoid any direct contact with pollinators, as well as near bodies of water to avoid runoff.
Solutions for Fungus
Copper Fungicide
Copper fungicide is our go-to fungicide for all things not fun including powdery mildew, downy mildew, black spot, rust, blight and more. Copper Fungicide can be used on ornamental and edible plants, and also turf grass. It can even be used up to the day of harvest in the veggie garden. Its active ingredient is Copper Octanoate (copper soap), and is suitable for organic gardening.
Spray on all plant surfaces for best results. Powdery mildew lives on the top of leaves, while downy mildew dwells on the bottom. Rust infections can move through tissue, so ample coverage is important. Preventative treatment is best, and we recommend that you begin treatment before disease symptoms typically appear. Repeat applications every 7-10 days and after a rain event.
Horticultural Oil - See information above
Neem Oil - See information above
If you would like guidance in how to best tackle a Summer plant pest or perennial health issue, feel free to stop in and ask! Otherwise, email us at hello@tonkadale.com (with pictures!) - we're here to help!