Summer bulbs: how to grow them indoors

Planting canna lily flowers in a summer garden.

Many people don’t bother to bring in the summer bulbs. They prefer to renew them every year rather than find a place for them to spend the winter indoors. Among those who keep them meticulously, the majority wait for the moment when they can work the soil in the spring to plant them directly in the garden.

However, it is very easy to store them inside. Better yet, some bulbs don't need a dormant period. During the cold season, they can stay among your tropical plants and even flower if the conditions suit them!


Table of contents
When to start summer bulbs
Tuberous begonias: how to start them indoors
How to prolong the flowering of dahlias
Calla lilies to colour the house and garden
Cannas, in winter and summer


When to start bulbs in the house

How to plant flowers in pot inside in Spring.

Starting summer bulbs indoors gives you a head start and helps extend your plants' blooming season. This is also what producers do to offer you dahlias that bloom on Mother's Day and cannas one metre high in June.

From mid-February to April, bulbs can be started indoors. To prevent your plants from growing too tall and stunted, provide them with plenty of light. Choose containers with drainage holes that allow excess water to drain away. Bulbs and tubers rot quickly in constantly soggy soil.


Tuberous begonias: how to start them indoors

How to start bulb flowers inside, grow and care for tuberous begonia house plant.

In nutrient-rich potting soil, plant tuberous begonia tubers 1 cm from the surface, concave side up. Lightly moisten the potting soil until the first leaves appear. Keep the potting soil cool, but never soggy. A little warmth under the pot encourages growth.

When the first leaves appear, place your containers in a bright location, sheltered from direct sunlight. Keep the soil moist.


How to prolong the flowering of dahlias

How to plant, grow and bloom dahlia flower bulbs.

Available in an almost infinite number of colours, the dahlia is one of the queens of the garden. The best way to prolong the flowering of dahlias is to start the bulbs indoors, from the first week of April. They will be able to flower from the beginning of summer until the first frost.

If you want to divide your tubers, do so before planting them. Use a sharp scissor to make a clean cut. To produce a new plant, the section must have at least one eye. Then wait a few days before planting them to give them time to dry.

Plant only one tuber per 4-litre pot so that your plant has enough space to grow. Store your pots in the house, in a sunny room, until all risk of frost has passed.

TIPS: For more flowers all season long, remove faded flowers as you go. For larger flowers (but fewer flowers), pinch the side buds.


Calla lilies to colour the house and garden

How to grow calla lilies, plantin, growing, planting bulbs.

Calla lilies add a refined touch to flower beds, borders and pots. Their elegant, colourful, trumpet-shaped flowers bloom easily, indoors and outdoors. However, they must be provided with well-draining soil since the tubers rot in waterlogged soil.

Begin planting 6 to 8 weeks before the last spring frost. Plant the tubers, gnarled side up, 1 to 2 inches deep. The tops of the tubers should be flush with the surface of the potting soil.

Place the pots near a window in the sun. The first leaves will appear fairly quickly. Calla lilies can be transplanted to the garden when the temperature is milder. As they prefer cool, protected locations, place them sheltered from the sun and wind.


Cannas, in winter and summer

How to grow and take care of canna lily.

Cannas offer an extraordinary summer spectacle with their brightly coloured flowers. In public places, they are planted in large numbers in flower beds, and they are the stars of flower pots. They are just as splendid on the deck… or in the living room during the cold season.

Oh yes! Cannas can be grown all year round, moving easily from the garden to the living room. In winter, in the house, they add an exotic touch that warms the atmosphere.

The good news is that the dormant period is optional for this plant with its green, red or bronze foliage. Better yet, when given ideal conditions, it can flower almost any time of the year.

Are you planning to decorate your living room next winter but your space is limited? Choose smaller varieties since large cannas can reach heights of 1.5 metres. If you are short on space, it is not essential to start your cannas in their final pot. Either way, cannas look just as impressive in flower beds as they do in containers.


How to grow cannas?

How to grow bulbs indoors, canna bulbs in pots.

Start canna rhizomes around mid-March, immediately in the containers where they will spend the summer or in 4-inch growing pots. (You can also plant several rhizomes in a temporary container and then divide so that each plant has sufficient space to develop.)

Our Premium Potting Mix promotes healthy growth. It contains sphagnum peat moss, mycorrhizae and a controlled release fertilizer that feeds for 9 months.
Place the rhizome horizontally on the potting soil, growing tip upwards. Cover it with at least 1 cm of substrate and water deeply. Then wait for the leaves to appear before starting regular watering. It won't be long.


What temperature for cannas?

Canna is a tropical plant native to the Caribbean. Heat encourages the appearance of the first shoots, so avoid placing it in a room that is too cool. Like the begonia, it will appreciate a little warmth under its pot at the start of growth. A heating mat will also make it happy.

Do you store your canna indoors for the winter? It will be more likely to flower if you place it next to a window where it will benefit from the sunlight.


When to water cannas?

Cannas prefer moist soil, so water as soon as the soil begins to dry on the surface. The water should be lukewarm (avoid cold water). It is normal for the plant to require more frequent watering as its roots develop. This can mean multiple waterings per week!


What lighting for cannas in the house?

The brightness doesn't matter much before the first leaves appear, but you can already offer them a place near a sunny window.

Also read: Complete guide to planting flower bulbs 


Storing the bulbs/tubers for the winter

As you are digging up the bulbs, shake off excess soil and cut off the stems. Most bulbs need a period of curing, or drying, before being put into storage, which is usually only 1 to 3 days, depending on temperature. 

A few plants, such as gladioli and callas, need a longer curing period of about three weeks. Keep the bulbs out of direct sunlight in a dry, well-ventilated area where the temperature is 15-20 °C. Once dried, select a crate or box. Do not use a sealed plastic container. Now add some dry peat moss, and then place the bulbs in the box. Top the bulbs with more peat moss and place the box in a location that is cool, dry and consistently dark (no light or they could sprout).

Look for an unfinished area of the basement away from heat sources or a place in an unheated garage that does not freeze. Of course, a root cellar is ideal. And don’t forget to label them and their particular colour before storing.