I live in Ottawa when is the best time to order Rose of Sharon? I want one that grows 4-6ft.
Thank you for contacting Toronto Master Gardeners.
The Rose of Sharon, Hibiscus syriacus, is a beautiful shrub which blooms later than most shrubs in the garden. It does best with full sun or partial shade and well drained soil. You will want to ensure you pick a variety that matches your zone. Ottawa can have harsh cold winters so a shrub that thrives in Toronto may not like the colder weather in your neighbourhood. Most of Ottawa is in growing zone 5, but you might want to confirm the zone where you live to determine the variety that will grow in your garden.
For ordering your shrub you are best to visit your local nursery to see when their shipments of the shrubs arrive. They will also have an idea which varieties will thrive in your area. Getting there early will give you an opportunity to chose the strongest best shaped specimens. Do check the information with the plant on the mature shrub size as many do grow larger than 4-6 feet. Flowers develop on new wood so timing of pruning to maintain the 4-6 foot size will need to be planned for post blooming so you do not lose any buds.
This link from the Missouri Botanical Gardens provides information on a white variety of Rose of Sharon that meets your height requirements. It can be grown in zones 5 to 8 so may be suitable for an Ottawa garden. You could search this site for more varieties in different colours.