The most common columbine flower problems are leafminers, powdery mildew, aphids, and crown rot. Leafminers top the list as the number one pest you'll face with this plant. Powdery mildew shows up in humid weather. Aphids cluster on new growth in spring. Crown rot hits your plant when the soil stays too wet around the roots for too long.
Columbine leaf miners are tiny flies that lay eggs on your plant's leaves. The larvae hatch and tunnel between the top and bottom layer of each leaf. You'll spot them by the winding white trails they leave behind. Iowa State Extension calls this the most consistent columbine pest. The bad news is that sprays don't work well against them because the larvae live inside the leaf where your spray can't reach. Sprays can also kill the good bugs that help keep leafminers in check.
I dealt with a bad leafminer outbreak on my hybrid columbines two years ago. In my experience, the best fix was to cut all the leaves down to the base after the flowers finished in June. Fresh clean leaves grew back within three weeks. The new growth came in clean and green without any miner trails at all on any leaf. Wisconsin Extension backs this up and notes that A. canadensis is much less prone to leafminers than hybrids. If miners drive you crazy, try switching to the native species for your beds.
Leafminers
- What you see: White winding trails on your leaves where larvae have tunneled through the tissue inside.
- Your fix: Cut all leaves to the ground after blooming ends. Fresh clean growth comes back in 2 to 3 weeks.
- Prevent it: Choose A. canadensis over hybrids since the native type resists leafminers much better.
Powdery Mildew
- What you see: A white dusty coating on your leaves that makes your plant look like it's been dusted with flour.
- Your fix: Remove the worst leaves by hand. Spray the rest with a baking soda and water mix if it gets bad.
- Prevent it: Space your plants 12 to 18 inches apart so air flows between them and dries the leaves fast.
Crown Rot
- What you see: Your plant wilts and dies even though the soil around it feels moist or wet to the touch.
- Your fix: Dig up the plant. Cut away any brown mushy roots. Replant in a spot with better drainage for the roots.
- Prevent it: Make sure your soil drains well. Add gravel or sand to heavy clay beds before you plant your columbine.
Aphids are the easiest problem to handle on your columbine. You'll see small green or black bugs on the tips of your stems and buds in spring. A strong blast of water from your garden hose knocks most of them off. Do this for 3 to 4 days in a row and your aphid problem should clear up. If they come back, a simple soap and water spray takes care of the rest. It won't hurt your plant or the bees and butterflies that visit your columbine for nectar.
You can dodge most of these issues by giving your columbine what it needs from the start. Plant yours in well-drained soil so your roots don't sit in water. Space your plants so air moves between them. Water the base of your plant and not the leaves. These three simple steps keep mildew and rot from getting a grip on your garden beds. Pick native species over fancy hybrids if you want fewer columbine pests and diseases in your beds each year. You'll spend less time fixing problems and more time just enjoying your flowers.
Read the full article: Columbine Flower Varieties and Care Guide
