Bulbs Planted Upside-Down? No Problem—Tropism Saves Them

Why They'll Still Grow

Plants exhibit tropisms—growth responses to stimuli. Foliage is negatively geotropic (grows away from gravity), so leaves emerge upward regardless of bulb orientation. Roots are positively geotropic (grow toward gravity).

Fascinating Tropisms

• Phototropism: stems lean toward light.
• Heliotropism: sunflowers track the sun.
• Hydrotropism: roots seek water.
• Thigmotropism: vines wrap on contact.
• Skototropism: bean vines grow toward shadows of vertical supports.

Bonus: Contractile Roots

Some bulbs (crocus, tulips) have contractile roots that pull them to optimal depth over years—even upside-down bulbs may right themselves.