Just when your plants were looking top-notch, they suddenly shriveled up and died.
Were they overwatered? Did they get too hot? Good guesses, but it wasn’t either of those. This time, the raiders came through. They drank and ate until there wasn’t anymore, then moved on to the next unsuspecting garden.
This is basic survival for some garden pests, whose slash-and-burn approach can devastate all kinds of plants. Here are some of the culprits:
Aphids – Colorado hosts more than 350 species of this tiny, notorious insect. Many of these species are hardly noticeable, but some leave a trail of destruction when they come through town. Too many aphids can cause leaf curling or leave sticky honeydew on the infested plant. The honeydew, in turn, attracts ants, flies, and bees, and can grow sooty mold. Aphids’ feeding habits will cause leaf curling in pine, crabapple and dogwood trees along with asters, tulips, roses and many other flowering plants.
There is good news: These intruders can be chased off with a garden hose. A jet of water will kill aphids or knock them to the ground, making it harder for them to find their way back. In the winter, cut back old growth on perennials such as columbines and lupines to remove the eggs the aphids laid on those stems in the fall.
Here are a few Northern Colorado plants that aphids love to nibble on: milkweed, columbines, roses, and walnut trees.
Narcissus Bulb Fly – These garden bugs will emerge in late May, laying eggs on narcissus, daffodils, and hyacinth. Their looks mimic bees, but their larvae destroy flower bulbs as they grow. Targeted parasitic wasp additions in late May can help control these pests.
Spider Mites – These tiny creatures live in large groups, spinning webbing together for shelter. They’ll attack your lawn, azaleas, spruce, conifers, grapes, phlox, and strawberries, causing foliage to yellow, often leaving it covered in webbing. Spider mites can be controlled with predatory insects, see our post here to learn about the “sheriff” bugs.
Leafminers – This variety of garden bugs don’t cause much damage, but they leave ugly trails and splotches on ornamental plants. Symptoms of leafminers resemble symptoms of leaf spotting fungi, however, the insects hollow out their tunnels, while the fungi will not leave any open spaces inside the leaf. Leafminers attack columbine, hollies, nasturtiums, spinach, and beets. To avoid leafminers, consider rotating plants each year and wait to plant beets after lilacs bloom when the species of leafminer that eats the beets is no longer active.
Slugs – Slugs’ favorite foods are young seedlings, but they also eat annuals, perennials, fruits, and vegetables. Their only dislikes are fragrant and fuzzy plants, such as lavender and lamb’s ears. These gastropods feed mostly at night, and they need moisture to thrive. To defend your garden, water in the morning so leaves and soil can dry before the creatures come out. Some gardeners will put out dishes of beer at closing time to attract and drown slugs, and some gardeners take the matter in hand, squishing the slugs whenever and wherever they appear.
In Northern Colorado, you’re most likely to see slugs in spring and fall at dusk.
Insect pests will find their way to your garden oasis, but they don’t have to take everything. Knowing friend from foe can help you spot and control those bothersome bugs.
Whether it’s for spring garden maintenance or you’re in the beginning, dreaming stages of building the perfect spring garden, we can help.