| Common Name | Silver Spurflower, Silver Shield |
| Genus | Plectranthus |
| Species | P. argentatus |
| Family | Lamiaceae |
| Life Cycle | Tender Annual (perennial in USDA Zones 10-11) |
| Tray Size | 125 |
| Plug Care | Transplant plugs into larger pots or directly into the garden after the last frost. Keep the soil consistently moist but not waterlogged as the plants establish. |
| Netting / Staking | Netting or staking is generally unnecessary, as 'Silver Shield' has sturdy stems and an upright growth habit that supports itself well. |
| Temperature Range | This plant will not tolerate frost, so it should be planted after all danger of frost has passed. It thrives in temperatures between 65-75°F (18-24°C), making it ideal for warm climates. |
| Spacing | Space plants 18-24 inches apart to allow sufficient room for growth and air circulation. This spacing encourages healthier plants and better foliage quality for cutting. |
| Soil Preference | 'Silver Shield' prefers rich, humusy, well-drained soils with a slightly acidic to neutral pH (6.0-7.0). Regular soil amendments with compost or organic matter can improve growth. Good drainage is key. |
| Day Length | This plant is day-length neutral and performs best in full sun to partial shade. In hotter climates, providing afternoon shade can prevent leaf scorching and ensure optimal foliage quality. |
| Pinching | Pinching is not required, as 'Silver Shield' naturally develops a full and bushy habit. However, light pruning can encourage additional branching if needed. |
| When to Plant | Plugs should be planted outdoors after the last frost date. Ensure the plants are watered well after transplanting to support rapid establishment in the garden. |
| Harvesting | Harvest stems early in the morning or late in the evening when temperatures are cooler to reduce stress on the plant. Select stems with mature, fully developed leaves for the best texture and appearance in arrangements. Use sharp, clean shears to make diagonal cuts to maximize water uptake. |
| Post Harvest Care | Immediately place cut stems in clean, lukewarm water to prevent wilting. Allow them to hydrate in a cool, dark location for several hours or overnight. Conditioned stems can be stored in a floral cooler at 36-41°F (2-5°C) and will last up to 2 weeks with proper care. Change the water and recut stems regularly to maintain freshness. |
| Diseases / Insects | 'Silver Shield' is relatively pest-resistant but can be affected by aphids, spider mites, and whiteflies. Good spacing and air circulation help prevent fungal issues such as powdery mildew. Avoid overhead watering, especially late in the day when foliage will remain wet overnight. |
| Bailey's Notes | Fertilize with a balanced, water-soluble fertilizer every 4-6 weeks during the growing season to support healthy foliage. While drought-tolerant once established, consistent watering will yield the best quality leaves for cutting. This plant pairs beautifully with flowering stems in bouquets, providing silvery contrast and a soft texture. |
| Resources |
Plectranthus argentatus 'Silver Shield' - Missouri Botanical Garden |