Heart to Heart® Midnight Oil Caladium

Light Needs

Full Shade to Partial Shade

(0 - 4 Hours Of Direct Sunlight)

Mature Height

15-20 Inches

Mature Spread

12-15 Inches

Container Role ?

×

What does this mean?

This shows how the plant is typically used in a container combo — Thriller (tall focal point), Filler (mid-height mass), or Spiller (trailing over the edge).

Tip: match plant habit to the role for the best designs.

Filler

This is the caladium you choose when you want drama without flowers. Heart to Heart® Midnight Oil Caladium carries near-black, strap-shaped leaves that appear deep charcoal from a distance, especially in stronger sun. Unlike traditional pink or white caladiums, this selection blends deep green and red tones into an inky surface with wavy margins. It grows 12–14 inches tall and 10–14 inches wide, forming a dense, upright mound that fills containers quickly.  

Part of the Heart to Heart® series, Caladium hortulanum 'THAI STR OF17-1082' was bred for improved vigor and sun tolerance compared to older shade-only types. It handles heat well and keeps producing fresh foliage through summer. It works beautifully in patio pots, hanging baskets, and mass plantings where repetition amplifies the moody effect. Deer tend to ignore it, and there is no need for deadheading since it’s grown strictly for foliage.

Heart to Heart® Midnight Oil Caladium Care

Plant in part sun to full sun, providing at least four hours of direct light for the darkest color expression. In very hot southern climates, a bit of afternoon relief prevents leaf scorch. Use a loose, well-draining potting mix or garden soil enriched with organic matter, with a slightly acidic to neutral pH around 6.0–7.0. Water thoroughly when the top inch begins to dry, keeping the root zone evenly moist but never waterlogged. Feed lightly with a diluted balanced fertilizer every one to two weeks during active growth; heavy feeding can damage the foliage.

If planting tubers, set them about 2 inches deep with the growing tip facing up. Wait until soil temperatures are consistently warm before planting outdoors. As a houseplant, place it near a bright window and maintain temperatures above 65°F for steady growth.

Heart to Heart® Midnight Oil Caladium Spacing

Space plants 10–14 inches apart in landscape beds for a full, layered look. For container planting, one plant fits nicely in a 10–12 inch pot, while three make a bold statement in a 16–18 inch patio container.

In containers, pair it with sweet potato vines for trailing contrast and begonias for added color. In landscape designs, combine with elephant ears for large-scale texture or edge with coleus to echo and intensify the dark foliage theme. We like using it as a dark anchor in bright combinations where other colors need contrast to stand out. 

Simple Plant Spacing Calculator

Planting Shape

Rectangle Circle Known Area

Length (ft)

Width (ft)

Diameter (ft)

Or enter radius below

Radius (ft)

Known Area (sq ft)

Plant Spacing On-Center (in)

Pattern

Square (grid) Triangular (staggered)

Fill edge gaps (max plants)

Enter area to see results.

Visual Preview

Print / Save PDF

Powered by

SKU:

CALMN-GC