Can I plant a baby blue spruce in o container( 40″w x 20″” h x 16″ diameter). It is a south eastern exposure, full sun and windy conditions.
Thank you for contacting Toronto Master Gardeners.
I assume your question relates to the conifer, Baby Blue Spruce, Picea pungens ‘Baby Blue’. This spruce can grow to about 30 feet tall at maturity, with a spread of 15 feet. It is not really suitable for containers.
The best evergreens for containers are small and slow growing with compact root systems. They are cold hardy at least two zones lower than Toronto’s plant hardiness zone which is 6. So, for a container evergreen, you would look for a dwarf variety rated for hardiness zone 4 or lower.
If you want to grow a blue coloured conifer in a container, I suggest you consider
a Globe Blue Spruce, Picea pungens ‘Globosa’.
This conifer grows in full sun to partial shade, and is rated hardiness Zone 2b.
It will grow to about 8 feet tall and spreads to about 6 feet at maturity, but can be kept smaller with regular light pruning.
It is considered to be drought-tolerant which is critical for your planned location where the sun and wind will dry the soil quite quickly. You will need to monitor soil moisture routinely and water whenever the soil is dry.
As to container size, it depends on the size of plant you buy at the nursery. As a general guide:
- one gallon evergreen plants should be planted in at least a 14” container.
- three gallon evergreen plants should be in at least a 18” container.
Overwintering outside is a challenge for container plants. Plants in larger pots and containers usually overwinter more successfully than those in small containers. An insulated container or added insulation is important, as is maintaining adequate moisture.
The Missouri Botanical Garden article on Growing Evergreens in Containers is a good resource for information on growing evergreens in containers. Note particularly the recommendations for Overwintering Plants in Containers.
Good luck with your container conifer.