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Full Sun Container Recipe: Super Spike & Petunia Planter | Fernlea

Container Garden Recipes

Full Sun Container Recipe: Super Spike & Petunia Planter

Need a statement piece for your patio? Try this "Super Spike" container recipe. We break down exactly how to arrange Petunias, Daisies, and Vines in an 18-inch pot for maximum impact.

By Fernlea Flowers

Orange flowers

Container Garden Recipe: Sample Container Idea (18″ Terra Cotta)

This 18-inch round terra cotta container is designed for full sun locations and delivers bold summer colour, height, and trailing interest. This recipe combines dramatic height with cascading vines for a professional “Thriller, Filler, Spiller” look. The planting can be adjusted to achieve a fuller or lighter look, depending on your preference and available space.

Terracotta planter filled with mixed flowers including white daisies, yellow and pink blooms, and trailing green foliage, placed outdoors on gravel with a graphic indicating “Full sun (8 to 12 hours/day).”

 

Planting Layout for This Container

This container garden recipe follows the proven thriller–filler–spiller method for visual balance and long-lasting appeal.

Container Size: 18-inch Round Planter (Terra Cotta or similar)

  • A: Super Spike (1) – The “Thriller.” A large Dracaena or Cordyline that adds vertical drama.
  • B: Sweet Potato Vine (2) – The “Spiller.” Adds lush, trailing lime or purple foliage.
  • C: Argyranthemum (Marguerite Daisy) (1) – The “Filler.” Provides classic daisy blooms.
  • D: Bidens (2) – Vibrant yellow flowers that weave through the arrangement.
  • E: Petunia (4) – The colour powerhouse. Fills gaps and spills over the edges.
Circle diagram with the letter A in the center and multiple letters B, C, D, and E placed around it in different colors on a light green background.

Note: This recipe thrives in Full Sun (8+ hours of direct light).

👉 Where to Buy our Annual Flowers

How to Plant Your Container Garden

Step 1 – Consider Location

Observe how much sun your container will receive throughout the day. Argyranthemum and Bidens require plenty of energy to bloom, so place this pot where it will receive at least 6 hours of direct sunlight per day.

👉 Learn more about Sun or Shade Garden Guide

Step 2 – Select Your Container

Choose a container with proper drainage holes. Terra cotta is breathable and attractive, but it dries out more quickly than plastic or glazed containers, so it’s essential to monitor moisture levels closely.

Step 3: Preparing the Container

For an 18-inch pot, weight can be an issue.

Pro Tip: Fill the bottom third of the container with crushed aluminum soda cans or empty plastic bottles. This improves drainage and makes the pot significantly lighter to move.

External resource:
Old Farmer’s Almanac: Container Gardening Basics

Step 4 – Fill With Soilless Media

A soilless growing medium composed of peat moss, perlite, and vermiculite offers excellent drainage while retaining sufficient moisture for healthy root growth.

  • Fill the container to 2 inches below the rim
  • Avoid compacting the soil

External resource:
University Extension: Potting Mixes Explained

Step 5 – Choose Your Fertilizer

Container plants rely on regular feeding. Choose one of the following:

  • Slow-release fertilizer: Mixed into the soil before planting and lasts 3–4 months (example: Osmocote 14-14-14).
  • Water-soluble fertilizer: Apply it weekly or biweekly, as directed by the manufacturer.

External resource:
Gardener’s Supply: Organic Fertilizers for Vegetables & Flowers

Step 6: Planting Order

  1. Center: Plant the Super Spike first in the middle.
  2. Surround: Place the Argyranthemum next to it for mid-height volume.
  3. Edges: Alternating the Petunias, Bidens, and Sweet Potato Vines around the edge to create a 360-degree display of trailing colour.

Step 7 – Plant Your Container

  1. Arrange plants before planting, starting with the tallest in the center.
  2. Dig holes slightly larger than each plant’s original pot.
  3. Remove plants by gently tipping pots upside down.
  4. Loosen the root balls to encourage outward growth.
  5. Backfill with soil and gently press down.

Water thoroughly until excess water drains from the bottom.

Hand dumping soil into large pot wearing gardening gloves
Gloved hands removing flower from plastic pot to transfer into large pot
Gloved hands removing flower from plastic pot and massaging the roots

Helpful Container Gardening Tips

  • Use crumpled aluminum cans in large containers to reduce soil weight.
  • Pinch buds from ever-blooming annuals before planting to promote root development.
  • Variegated foliage may scorch in intense sun — monitor exposure.
  • Fragrant annuals are best placed near decks, patios, doors, or walkways.

Tips for a Professional Look

  • Pinch for Bushiness: Don’t be afraid to pinch off the early buds on petunias and bidens when you first plant them. This sacrifice forces the plant to branch out, creating a fuller container later.
  • Deadheading: Argyranthemum (Daisies) look best when you snap off the faded flower heads. This encourages new buds to form quickly.
  • Watering: An 18-inch pot holds water well, but in the peak of summer, check it daily. If the Sweet Potato Vine leaves look droopy, give it a drink immediately.

External resources:

Final Thoughts

This 18″ terra cotta full sun container garden recipe delivers season-long colour, texture, and structure. With the right soil, fertilizer, and proper plant placement, this planter will thrive throughout the summer.

👉 View More Container Garden Recipes

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