Many summer-flowering bulbs and corms need to be protected from freezing temperatures. They are stored indoors from the first fall frost until the following spring. Most summer-flowering bulbs come from warm climates and prefer to be started in warm soil. Planting many types of bulbs early indoors gives them a head start to the season while providing the warm soil they require.
Begonias
Start tuberous begonias mid-February to late April. An early start translates to a longer bloom period.Begonia tubers have a concave side which should be planted facing up. Plant ½” below the surface.Water sparingly until growth appears. If the potting mix is too moist it can cause the tubers to rot. Bottom heat encourages new growth to begin. I place the pots on top of my refrigerator. You can also place them on top of an indoor light stand to benefit from the warmth. Once new growth appears, move the pots to a bright location protected from direct sunlight. Increase watering but do not overwater.
Canna Lilies
For many years the spectacular tropical foliage and brilliant flowers of Cannas have been a mainstay in public parks and gardens. Many of the new varieties feature multi-coloured flowers that are best viewed in the home garden, and will do quite well grown in containers.
- Start canna lily bulbs indoors in mid-March.
- Plant cannas directly in one gallon pots.
- Tubers should be planted horizontally.
- Provide bottom heat as with begonias.
- Once new growth begins, move pots to a sunny window.
Dahlias
Dahlias are easy-to-grow tubers. They are available in a great variety of colour – white, yellow, pink, purple, red, orange, maroon, etc. The first week of April is the best time to start dahlias indoors. Pot them up early to enjoy blooms from early summer until the first autumn frost. Before potting your tubers you may choose to divide them. You can divide the tuberous root with a sharp knife. Each piece of root must have at least one eye to produce a new plant. Allow the cut pieces to dry for a few days before planting. Use a one gallon pot for each tuber to ensure the plant has the necessary room to grow. Move your dahlias to a sunny location indoors until all danger of frost has passed. Outdoors, place in full or partial sun. Once dahlias start blooming it is important to deadhead regularly. This encourages the production of new blooms. Pinch off side shoots if you prefer larger (but less) blooms.
Calla Lilies [Spathaphilum]
Eye-catching tropical flowers, originally from South Africa. The blooms are upright growing and trumpet-shaped, about 6 inches tall and 2 to 3 inches across. Many varieties have bright speckles on their broad, sword-like leaves. Calla lilies are ideal for use in beds, borders or in containers either indoors or out.
- Containers must drain freely. Calla lily tubers will rot if they sit in waterlogged soil.
- Plant with the top of the tuber just below the soil surface.
- Calla lily bulbs have a ‘knobby’ side which should be planted facing up.
- Place containers in a window with direct sunlight. New growth will begin as the soil warms.
When planting out in the garden choose a sheltered location out of the sun and wind. Calla lilies like a cool, protected home. Summer flowering bulbs can provide a summer full of colour and enjoyment!
