As the calendar turns to March, the horticultural world enters a critical transition period. While the ground begins to thaw, gardeners across the country are moving into high gear to secure a lush, vibrant summer landscape. This month marks the essential planting window for summer-flowering bulbs, alongside a final opportunity for those who missed the autumn cycle to establish spring favorites “in the green.”
Navigating the Bulb Calendar
Understanding the distinction between seasonal bulbs is vital for a successful display. While spring classics like tulips and daffodils are typically set in the autumn, summer-flowering varieties—including dahlias, gladioli, and begonias—require a spring start. These specimens thrive as the soil warms, promising a burst of architectural interest and vivid color from mid-summer until the first frosts of autumn.
Strategies for Outdoor Planting
Many hardy summer varieties can be introduced directly to the garden beds from late March through April. Experts recommend prioritizing well-drained soil enriched with organic matter to prevent bulb rot.
- Dahlias and Gladioli: These garden staples offer high rewards. Dahlias should be planted 10–15 cm deep in sunny, sheltered spots. For a continuous harvest of cut flowers, gardeners are encouraged to plant gladioli corms in two-week intervals through May, ensuring a staggered bloom schedule.
- Architectural Interest: For those seeking exotic flair, the Eucomis (Pineapple Lily) and Crocosmia are excellent choices. Crocosmia, particularly the ‘Lucifer’ cultivar, is a favorite for pollinators, while the Eucomis provides a distinctive tropical silhouette in late summer.
Accelerating Growth Indoors
In cooler climates, starting “tender” bulbs indoors provides a necessary head start. Species such as Cannas and Tuberous Begonias benefit from being potted in a frost-free environment before the outdoor transition. Begonias should be nestled hollow-side up in moist compost, while Canna rhizomes thrive after a 24-hour warm water soak to break dormancy. Once the risk of frost passes in late May, these established plants can be hardened off and moved to their permanent outdoor positions.
The “In the Green” Alternative
For gardeners who missed the traditional autumn planting window for spring blooms, “in the green” bulbs offer a professional solution. Unlike dormant bulbs, these are sold while actively growing, usually just after flowering. This method is the gold standard for establishing Snowdrops and Bluebells, as they tend to transplant and naturalize far more successfully than their dry-bulb counterparts.
Essential Maintenance and Protection
Success in the bulb garden relies on three pillars: drainage, nutrition, and protection. Most bulbs perish in waterlogged conditions; therefore, incorporating grit or utilizing raised beds is recommended for heavy clay soils.
Once growth emerges, the application of a high-potassium liquid fertilizer every two weeks will shift the plant’s energy from foliage production to flower development. Furthermore, gardeners must remain vigilant against late-season frosts, keeping horticultural fleece ready to shield vulnerable new shoots.
Guarding Against Pests
The emergence of tender green shoots in spring inevitably attracts slugs and snails. Integrating biological controls, such as nematodes, or utilizing copper barriers can mitigate damage. Additionally, gardeners should monitor container-grown plants for vine weevil larvae and check new dahlia growth for aphids to ensure a healthy start to the growing season.
By diversifying planting types and utilizing both indoor and outdoor techniques this March, enthusiasts can ensure a resilient, multi-layered garden that performs from the first thaw through the end of the year.