Garden Design Step 8: Choosing Plants That Work Together

Up until now, you’ve designed your garden without naming a single plant — and that’s intentional.

Once your structure, spacing, color blocks, and heights are in place, plant selection becomes much simpler. Instead of choosing plants one by one, you’re choosing them based on form, texture, and role.

This is how cohesive gardens are built.

Start With Flower Shape, Not the Plant Name

When selecting flowering plants, think in shapes, not species.

Most successful plantings include a mix of:

Spiky flowers
These add vertical emphasis and energy
Think: upright forms like hydrangea paniculata, veronica (Speedwell) and liatris

Umbel or disc-shaped flowers
These feel grounding and familiar
Think: broad, flat faces like Shasta daisies, sedum, mophead hydrangeas or echinacea

Airy flowers
These soften everything and add movement
Think: light, floating blooms like coreopsis, gaura, catmint & bowman's root

Using a combination of these forms keeps a garden from feeling flat or repetitive, even when the color palette is limited.

Here is a spot in my yard with all 3 forms.

The yellow coreopsis is airy, the white shasta daisy is an umbel and the pink agastache is a spike. You will notice a lily about to bloom which can function also as a spike.

Then Layer in Foliage Variety

Flowers come and go throughout the season but foliage is what carries the garden for most of the year.

There are very few flowers that bloom for more than a few weeks at a time. Even a continually blooming rose has lulls between blooms or is less spectacular after its spring show.

Aim for contrast and balance by mixing:

Leaf Size

• Large leaves for boldness and structure
• Medium leaves to connect elements
• Grassy or fine-textured leaves for softness and movement

Leaf Texture

• Glossy leaves to reflect light and feel polished
• Fuzzy or matte leaves to absorb light and add depth

This interplay of size and texture adds interest even when nothing is in bloom.

Look at how leaves can be drastically different with just foliage plants:

Revisit Your Plan as You Choose

As you start assigning real plants to your color and height blocks:

• Stay true to your original spacing
• Choose plants that fit the role, not just the look
• Repeat plants where you planned repetition earlier

This is where discipline pays off — and where many gardens either come together or fall apart.

Pro Tip: Start by choosing 3-5 flowering plants and 3-5 foliage plants. Make sure at least one of the foliage plants is a grass and one is an evergreen. Choose flowering plants that at least hit spring, summer and fall. 

Example recipe for a warm purple, pink, white color palette in full sun and medium mosture soil:

Flowers:

1. Shasta Daisy (Umbel flower, mid summer, white)
2. Blue Fortune Agastache (Spike flower, late summer/fall, purple)
3. Pink Gaura (Airy flower, late summer/fall, pink)
4. Catmint (Airy Flower, summer through fall, purple)
5. White Peony (Umbel Flower, spring, white - bonus foliage fall color)

Foliage:

1. Lemon Candy Ninebark - chartreuse foliage, smaller leaves
2. NewGen boxwood - evergreen, small glossy leaves
3. Little Bluestem - blue grass with great fall color
4. Sage - fuzzy colorful foliage
5. Glow Stick Japanese Holly - upright, evergreen, chartreuse

Remember in this mix, the peony and shasta daisy will have medium green foliage to contribute. The gaura and catmint will have small foliage and the blue fortune agastache will have medium, fuzzier foliage.

Here is AI's attempts at that mix. I would be better in real life if the plants were repeated and more intermixed.

A Free Plant Guide to Help You Choose

To make this step easier, I’ve created a free downloadable booklet with plant recommendations specifically for New England Zones 5–6, organized by:

1. Color
2. Plant type
3. Sun exposure

This guide is designed to plug directly into the design process you’ve been following thus helping you choose plants that not only look good together, but actually thrive where you live.

What Comes Next

Once plants are selected, the final step is refining which includes checking spacing, thinking through bloom timing, and planning for maintenance and seasonal change.

We’ll wrap up this series with tips on making your garden successful long-term, not just beautiful at planting time.

This is also exactly how we work through garden planning in my Garden Design Workshops at Scout Hill Farm, where I’ll guide you step-by-step from blank paper to a clear, plantable plan. Subscribe to email notifications to be notified the next time we have a workshop! Or purchase consulting hours for 1:1 design & attention.