Summer-flowering bulbs are best planted outdoors once the soil has warmed up and the risk of frost has passed. In southern England, this typically occurs in late April, while in Scotland and northern England, it is often mid to late May. Many summer bulbs, including tubers and corms, originate from warmer climates and are sensitive to cold temperatures.
Planting Guidelines for Different Bulb Types
Lilies are surprisingly hardy and can be planted in late autumn or early spring, provided the ground is not frozen or waterlogged. Tender bulbs, such as dahlias, cannas, and begonias, should be started in pots under cover and moved outside once night-time temperatures consistently stay above freezing. Hardier bulbs, like crocosmia and gladioli, can usually be planted directly into the ground as soon as it is workable.
Soil and Planting Techniques
Plant bulbs in well-drained soil in a sunny, sheltered spot, at a depth of two to three times their own size. Ensure the pointed end, or 'nose', faces upwards. If the orientation is unclear, planting the bulb on its side allows it to adjust naturally. Summer bulbs are prone to rot in wet conditions; if you have heavy clay soil, add a handful of horticultural grit to the bottom of the planting hole to improve drainage.
Winter Storage and Maintenance
After the first autumn frosts, dig up tender bulbs, allow them to dry thoroughly, and store them in a cool, frost-free location for the winter. This practice helps preserve them for the next growing season.
Top Summer Bulb Choices for Colour and Fragrance
Here are ten popular summer bulbs to enhance your garden with vibrant colours and delightful scents:
- Dahlias (tubers): Known as the kings of summer, dahlias bloom in every colour except blue from July until the first frosts. Recommended varieties include 'Bishop of Llandaff' with dark foliage and red flowers, and 'Café au Lait' featuring huge creamy-pink blooms.
- Lilies (bulbs): Perfect for adding height and fragrance, Oriental lilies are famously scented, while Asiatic lilies offer bold, bright colours. Try 'Stargazer' in pink and white or 'Orange Oriental' for a fragrant display.
- Gladioli (corms): These provide dramatic vertical spikes of colour and make excellent cut flowers. Varieties like 'Passos' in purple and white or 'Ivory Priscilla' in creamy white are highly recommended.
- Begonias (tubers): Ideal for gardens with partial shade, begonias have a long flowering season and look stunning in hanging baskets or window boxes. Consider 'Bossa Nova Night Fever Papaya' in dark red or 'Fragrant Falls' with its sweet perfume.
- Crocosmia (corms): Very hardy and easy to grow, crocosmia produces arching sprays of hot red, orange, or yellow flowers that attract bees. Popular choices include 'Lucifer' in vivid red and 'Sunglow' in yellow.
By following these tips, you can create a stunning summer garden display that thrives throughout the season.
