Protecting Your Vibrant Colorado Roses from Japanese Beetles

Denver, Colorado’s semi-arid climate and, at times, unpredictable weather can be tricky for gardeners to deal with; roses, however, will thrive here when properly cultivated and cared for. In fact, Colorado has been known to produce the most vibrantly-colored roses in the United States! Most rose varieties prefer well-draining soil in open areas exposed to full sun, making them the perfect addition to a Colorado garden.

Roses are susceptible to damage from a large number of garden pests, including aphids, thrips, and wasps. One of the more notorious rose garden pests is known as the Japanese beetle, an invasive insect that loves to eat the buds, leaves, and flowers of bushes. Though these insipid pests are attracted to most any type of plant, they will prey on a prized bed of roses with total impunity, reducing your hard work to shambles in the blink of an eye.

About Japanese Beetles

Japanese beetles (Popillia japonica) are a highly invasive type of scarab beetle. Introduced to America through Japanese imports in the early 1900s, the Japanese beetle has very few natural enemies in the West and thrives on over 300 different species of plants. Their larva ruins grass from the roots on up, while the adult beetle chooses the leaves, buds, and flowers of most plants. They are especially fond of rose bushes, due to their abundance of fragrant flowers that provide a lucrative food source for the adult beetles.

These hungry pests are approximately 1/2 inch long. They have metallic green heads and coppery wings with white tufts of hair growing near their legs. Japanese beetle grubs are white or off-white with a brown head, thick, and have easily distinguishable legs.

Appetite for Destruction

In addition to ravaging rose bushes, adult Japanese beetles cause damage to a huge variety of other plants, like basil, apple trees, birch trees, and several other types of decorative flower bushes. The leaves become latticed and frail, a condition that is called “skeletonizing” lose their green color and fall off, causing unsightly damage to your bushes. Flower petals become dry, brown, and tattered, while the buds are devoured before maturing.

The larvae of the Japanese beetle is only hungry for the roots of grass. While the larva will leave your roses alone, remember that the presence of grubs means there will be beetles to contend with. We recommend removing the grub infestation as soon as possible, as well as monitoring your garden for more signs of beetle activity.

Younger plants are at risk for deadly attacks by Japanese beetles. Though well-established bushes, trees, and plants can withstand a good deal of nibbling before they are affected, the beetle can kill unwell or immature plants. The beetle’s munching can lead to stunted production in fruit-bearing plants, making for a smaller harvest. Similarly, flower bushes will produce less blossoms if the beetles are left to their own devices for too long.

Humane Ways to Get Rid of the Japanese Beetle in Denver, Colorado

We do carry safe chemical options to help you remove Japanese beetles quickly and with ease, but here are four humane ways to get rid of Japanese beetles and their larvae before they ruin your roses:

Parasitic roundworms.

Introducing these beneficial nematodes to your garden will reduce the grub population without using harmful chemicals. Though you can integrate these naturally-occurring organisms at any time when your soil is properly watered, it’s best to apply them in spring as grubs are coming up to soil and in fall as they are going back down into the soil. Apply nematodes early in the morning or late at night and be sure to keep soil moist for up to two weeks. The garden-friendly parasitic roundworm, when ingested by the hungry beetle larva, releases a type of bacteria that kills the grub within a day or two. This option is very garden-friendly, since the nematodes will target other species of beetles who might harm your garden.

Regular yard maintenance.

Make sure to harvest your garden appropriately to avoid attracting beetles. Japanese beetles are extremely fond of rotting, fermenting fruit, and will flock to overripe produce on the ground near any fruit-bearing trees. Keeping these areas tidy will reduce the risk of inviting groups of invasive beetles into your yard. Additionally, any overgrown flower beds and old garden plots should be carefully monitored for beetle infestations.

Removing by hand.

Though tedious, the most humane way to remove pesky Japanese beetles from your garden is to locate them, gently pick them up with gloved hands, and place them in a bucket of soapy water. Thoroughly scour your garden in the early part of the morning for any visible pests, taking care not to crush them (to prevent more beetles from being attracted to the pheromones the dead one releases). This method is worth the time, since it poses absolutely zero further risk to your rose bushes and doesn’t require any special supplies.

Use a combination of non-toxic chemical options.

We proudly carry Milky Spore, Beetle Gone, Grub Gone, and AzaSol. Any combination of these products can save your lawn from Japanese Beetles. Of course, we know that some of our customers also want the problem taken care of fast which is why we also carry stronger products like Eight, Bug Blaster, and Grub Free Zone.

The Country Fair Garden Difference

At Country Fair Garden Center, we have tons of experience dealing with Denver, Colorado garden pests like Japanese beetles. We care about your garden as if it were our own! Come visit us for supplies like beneficial nematodes and Japanese beetle bags, and let our trained staff help you get your roses back to their blooming beauty! We’re always happy to help you find the solution that will best suit you and your plants.

Additionally, Country Fair Garden Center carries a beautiful selection of rose bush varieties and the supplies to care for them! Let us help you choose a locally cultivated rose bush for your Denver, CO space and watch it thrive, year after year.