Intermediate Sedum Care: Varieties, Design & Seasonal Interest

Advanced Sedum Cultivation

Beyond basic care, successful sedum growing involves understanding the diversity within the genus, selecting appropriate species for specific situations, and integrating these versatile plants into thoughtful designs.

Understanding Sedum Diversity

Taxonomic Overview

The genus Sedum presents significant taxonomic challenges:

The "Sedum Problem":

• Genus is highly polyphyletic
• Species found in 4 of 6 major clades
• Many species reclassified to other genera
• Ongoing revision and debate

Common Reclassifications:

Practical Note: Many plants are still sold under the name "Sedum" regardless of current taxonomy. We'll use common horticultural names here.

Major Groups

True Sedum (Sedum sensu stricto):

• Mostly small, creeping species
• S. acre, S. album, S. reflexum
• Often yellow or white flowers

Hylotelephium (Upright Stonecrops):

• Border plants
• 'Autumn Joy', 'Matrona', S. spectabile
• Pink, red, or white flowers
• Die back in winter

Phedimus:

• Mat-forming
• S. spurium and relatives
• Often colored foliage
• Evergreen or semi-evergreen

Species and Cultivar Selection

By Growth Habit

Groundcover/Mat-Forming (2-6 inches):

Intermediate (6-12 inches):

Upright/Border (18-24 inches):

By Foliage Color

By Flower Color

Design Applications

Rock Gardens

Key Principles:

1. Match scale: Small sedums for intimate areas, larger for bigger spaces
2. Create contrast: Mix textures and colors
3. Allow for spreading: Space appropriately
4. Include vertical elements: Rocks, upright plants

Design Ideas:

• Edge paths with creeping types
• Fill between rocks with compact varieties
• Create color sweeps with massed plantings
• Include fall-blooming types for late interest

Living Walls and Crevices

Best Choices:

• S. acre (tolerates shade)
• S. album (very adaptable)
• S. reflexum (cascading habit)
• S. hispanicum (tiny, delicate)

Installation:

• Plant in cracks and crevices
• Use lean mortar or moss for footholds
• Water initially until established
• Self-seeds and spreads

Container Gardens

Combinations:

• Mix creeping sedums with echeverias, sempervivums
• Add height with grasses or agaves
• Include trailing species at edges
• Use shallow, well-drained containers

Winter Considerations:

• Protect containers from freeze-thaw
• Move close to house or bury pots
• Ensure drainage holes don't freeze

Border Plantings

Upright Sedum Uses:

• Middle to back of perennial borders
• Foundation plantings
• Butterfly and pollinator gardens
• Late-season interest

Companion Plants:

• Ornamental grasses
• Rudbeckia
• Asters
• Russian sage
• Echinacea

Green Roof Applications

Why Sedums Excel on Green Roofs

Best Species for Green Roofs

Primary Choices:

• S. acre
• S. album
• S. reflexum
• S. sexangulare
• S. spurium cultivars

Substrate Requirements

Establishment

1. Install drainage layer
2. Add substrate evenly
3. Plant plugs or lay pre-vegetated mats
4. Irrigate initially for establishment
5. Monitor first year for bare spots

Propagation Techniques

Stem Cuttings

Best for: All sedum types

Timing: Spring through early summer

Method:

1. Cut 3-4 inch stem tips
2. Remove lower leaves
3. Allow to callus 1-2 days
4. Insert in gritty mix
5. Keep barely moist
6. Roots in 2-3 weeks

Division

Best for: Upright types, clump-formers

Timing: Early spring as growth begins

Method:

1. Dig entire clump
2. Shake off excess soil
3. Cut through crown with sharp spade
4. Ensure each division has roots and shoots
5. Replant immediately
6. Water to settle

Leaf Cuttings

Best for: Thick-leaved creeping types

Method:

1. Remove healthy leaves
2. Let callus 1-2 days
3. Place on moist gritty soil
4. Mist occasionally
5. Plantlets form at base

Layering (for creeping types)

Method:

1. Pin stems to soil with wire or rock
2. Ensure nodes contact soil
3. Roots form at nodes
4. Sever and transplant rooted sections

Seasonal Care Optimization

Spring

Summer

Fall

Winter

Problem Solving

Pest Issues

Aphids:

• Sometimes on flower stalks
• Hose off with water
• Rarely serious

Slugs/Snails:

• May damage soft growth
• Iron phosphate bait
• Improve air circulation

Disease Issues

Crown Rot:

• From excessive moisture
• Improve drainage
• Remove affected plants
• Let soil dry

Rust:

• Orange spots on leaves
• Remove affected leaves
• Improve air circulation
• Fungicide if severe

Cultural Problems

Understanding sedum diversity and matching species to site conditions enables you to create stunning, low-maintenance plantings from green roofs to borders.