As the ground thaws and daylight lingers, March marks a pivotal transition for gardeners. This is the month where strategic planning meets physical labor, offering a unique window to both Rectify missed autumn opportunities and lay the foundation for a vibrant summer display. By balancing outdoor planting with indoor propagation, you can ensure a continuous succession of blooms from the first signs of spring through the final frosts of autumn.
Navigating the Two Seasons of Bulbs
In the horticultural world, “spring bulbs” is often a catch-all term that requires clarification. Spring-flowering bulbs, such as tulips and daffodils, are traditionally planted in the fall. However, if you missed the October window, you can still find “in the green” specimens—plants already in active growth—at garden centers now. These are far more successful for late-season establishment than dry bulbs.
Conversely, summer-flowering bulbs, including dahlias and gladioli, require planting now. These tropical and sub-tropical beauties crave the warming soil of spring to fuel their mid-year performance.
Essential Bulbs for Immediate Outdoor Planting
For those in milder climates, several varieties can be tucked directly into garden borders starting in mid-March.
- Dahlias: These garden versatile favorites should be planted 10–15 cm deep in rich, well-drained soil. Because they are susceptible to late frosts, keep horticultural fleece nearby.
- Gladioli: To avoid a single, short-lived burst of color, plant these corms in two-week intervals through May. This staggered approach ensures a steady supply of architectural flower spikes for cutting.
- Crocosmia: Known for attracting pollinators, varieties like ‘Lucifer’ thrive when planted in clumps in sunny or partially shaded spots.
- Eucomis (Pineapple Lily): For a touch of the exotic, these hardy bulbs produce distinctive tufted spikes that bloom late in the season, bridging the gap between summer and autumn.
The Advantage of an Indoor Start
Starting tender varieties indoors during March provides a significant head start, particularly in cooler regions. Tuberous Begonias should be nestled hollow-side up in moist compost at roughly 19°C. Similarly, Cannas benefit from a 24-hour warm water soak before being potted up in a frost-free environment.
For Dahlias, starting tubers in pots on a sunny windowsill allows for stronger root development. Once the threat of frost has passed in late May, these established plants can be “hardened off”—gradually acclimated to outdoor temperatures—before final transplanting.
Proven Strategies for Growing Success
Success with bulbs relies on three pillars: drainage, depth, and defense. Most bulbs will rot in waterlogged earth; if your garden contains heavy clay, incorporate grit or organic matter to improve aeration. As a general rule, plant bulbs at a depth roughly three times their diameter to protect against temperature fluctuations and provide structural support.
Once green shoots appear, the nutritional demands of the plant increase. Apply a high-potassium liquid fertilizer, such as a tomato feed, every fortnight to prioritize flower production over leaf growth.
Vigilance Against Pests and Frost
The primary spring threats are environmental and biological. Sudden overnight freezes can blacken new growth, making protective covers essential. On the biological front, slugs and snails are drawn to succulent new shoots. Utilize nematodes or copper barriers to protect your investment. For container-grown begonias, watch for vine weevil larvae, which can be managed with targeted biological controls applied directly to the soil.
By acting now, you transform the quiet landscape of March into the lush, floral abundance of July. Whether you are naturalizing bluebells in a shaded corner or prepping show-stopping dahlias for a sunny border, the work done this month defines the beauty of the seasons to come.