Signs That Pests Have Taken Over Your Brunnera Plant (& What To Do About It)

Spring is often a gardener's favorite time of year. Tulips and daffodils peek through the soil, and leafy perennials emerge. It's the season when we can delight in the fruits of our labor, seeing everything in full bloom after a period of dormancy.

One spring showstopper is Brunnera macrophylla — a beautiful perennial you'll want to grow next to your spring bulbs — with its heart-shaped leaves and delicate blue or white flowers. Depending on the variety, its leaves range from a vibrant chartreuse to a dramatic dusting of silver against prominent dark green veins. The brunnera, which maxes out at a height of 18 inches and a sprawl of 2 1/2 feet, is typically grown as a ground cover and thrives in USDA hardiness zones 3 through 8. It loves moist soil, growing most happily in the shade. Unfortunately, gardeners aren't the only ones who like seeing their brunnera thrive. If you spot irregular-shaped holes, slime trails, or leaves that are wilted, curled, or blotchy, those may be signs that pests like aphids, slugs, and foliar nematodes also are enjoying your brunnera plants.

Let's start with aphids — those tiny light green oval-shaped bugs that suck juice from plants, leaving foliage dry, wilted, and discolored. Aphids usually target new growth and the underside of leaves, so keep a close eye on those newly unfurled leaves that could easily camouflage these pests. If you're conducting routine checks, you can probably spot aphids before they do any damage. But wait too long and you may end up with more serious symptoms.

Depending on the amount of bugs that you're dealing with, prune or spray your brunnera with a strong stream of water— the lazy gardeners' trick for dealing with aphids in the garden. For more extreme cases, the University of California Agriculture & Natural Resources' Integrated Pest Management Program recommends multiple applications of insecticidal soaps, petroleum-based horticultural oils, or plant-derived oils (such as neem or canola oil) — like Bonide All Seasons Horticultural & Dormant Spray Oil and Natria Neem Oil Spray for Plants — which will coat and kill the aphids.You can also easily get rid of pesky aphids with this brilliant tip. 

Slugs are harder to spot, but a trail of slime and holes in your leaves are telltale signs that they were present. They're most active at night or during cooler times of day, and will often hide in damp, shaded areas when the sun is high. Make the area around your brunnera as unappealing as possible by minimizing hiding spots like pots, bricks, large stones, and heavy mulch — anywhere a slug can find respite from heat — and keep the spot as dry as possible. At dusk, set out a shallow container of beer, which will attract and drown the pests. You can also try any of Sluggo's products, like the Wildlife and Pet Friendly Snail & Slug Killer, which are organic and safe for wildlife and pets.

If your brunnera's leaves are curling or getting angular splotches between the veins that turn brown and brittle, you're likely dealing with foliar nematodes — microscopic parasitic worms that commonly attack these plants. Unfortunately, these pests aren't as simple to eradicate as aphids and slugs. In this case, prevention is your best bet. Since foliar nematodes typically hitch rides into your garden with other infected plants, shop only at trusted, quality nurseries and scan potential purchases for signs of foliar nematodes. Isolate plants that you suspect are infested, sanitize gardening tools and surfaces that have been exposed to nematodes, and don't take cuttings from plants that might be infected.If you're certain that your brunnera is suffering from foliar nematodes, get rid of it as quickly as possible.