What Is the Natural Way to Kill Canna Bulbs Already in the Ground?

Cannas need help to get out of your garden bed.

Gardeners love cannas because of their big, bright flowers and easy-growing attitude. You can plant these beauties in your garden and forget them. They'll keep blooming and coming back year after year--even when you no longer want them to. Most gardeners find out just how tenacious cannas are when they try to get rid of them. No matter how many times you cut their foliage, they'll grow back. If you want to keep herbicides out of your garden, the most natural way to get rid of cannas is by careful digging.

Things You'll Need

• Shovel

Instructions

1. Water dry soil to 3 to 4 inches deep. In long-established canna beds, the soil can be quite compacted. Digging compacted soil is hard on your arms and your shovel.

2. Dig up the canna bulbs. Keep an eye on the canna's foliage for an idea of where to dig. Canna tubers grow in clumps and sit 3 to 4 inches below the soil.

3. Sift through the soil with the blade of your shovel. Look for canna bulbs left behind after digging. Extend the hole an inch or so in all directions. Small canna bulbs easily escape notice on the first dig. If left in the ground, they will sprout in spring and spread over subsequent seasons.

4. Compost, give away or dispose of the canna bulbs. Don't leave them on the ground. They may take root on the spot.

References

• Karchesky Canna Collection: Tips for Growing Cannas and Other Tender Perennials
• Iowa State University Extension: Ask the Experts From ISU
• Horn Canna Farm: FAQ
• Floridata: Canna X Generalis
• Texas Gardener; Cool Plants for Hot Months; Zoe Nonemaker