Hydrangea macrophylla 'Kardinal'
Kardinal Hydrangea flowers
(Photo courtesy of NetPS Plant Finder)
Height: 4 feet
Spread: 4 feet
Hardiness Zone: 6b
Other Names: French Hydrangea, Bigleaf Hydrangea
Group/Class: Teller Series
A showy shrub that is compact and at the same time open, featuring deep green glossy leaves; large lace cap blooms with sterile florets surrounding central fertile flowers in a perfect cardinal red
Kardinal Hydrangea features bold red lacecap flowers at the ends of the branches from early to mid summer, which emerge from distinctive sky blue flower buds. The flowers are excellent for cutting. It has forest green deciduous foliage. The glossy pointy leaves do not develop any appreciable fall colour.
Kardinal Hydrangea is a multi-stemmed deciduous shrub with a more or less rounded form. Its relatively coarse texture can be used to stand it apart from other landscape plants with finer foliage.
This shrub will require occasional maintenance and upkeep, and should only be pruned after flowering to avoid removing any of the current season's flowers. It has no significant negative characteristics.
Kardinal Hydrangea is recommended for the following landscape applications;
- Mass Planting
- General Garden Use
- Container Planting
Planting & Growing
Kardinal Hydrangea will grow to be about 4 feet tall at maturity, with a spread of 4 feet. It tends to be a little leggy, with a typical clearance of 1 foot from the ground. It grows at a fast rate, and under ideal conditions can be expected to live for approximately 20 years.
This shrub does best in full sun to partial shade. You may want to keep it away from hot, dry locations that receive direct afternoon sun or which get reflected sunlight, such as against the south side of a white wall. It requires an evenly moist well-drained soil for optimal growth. It is not particular as to soil type, but has a definite preference for acidic soils. It is highly tolerant of urban pollution and will even thrive in inner city environments, and will benefit from being planted in a relatively sheltered location. Consider applying a thick mulch around the root zone in both summer and winter to conserve soil moisture and protect it in exposed locations or colder microclimates. This is a selected variety of a species not originally from North America.
Kardinal Hydrangea makes a fine choice for the outdoor landscape, but it is also well-suited for use in outdoor pots and containers. Because of its height, it is often used as a 'thriller' in the 'spiller-thriller-filler' container combination; plant it near the center of the pot, surrounded by smaller plants and those that spill over the edges. It is even sizeable enough that it can be grown alone in a suitable container. Note that when grown in a container, it may not perform exactly as indicated on the tag - this is to be expected. Also note that when growing plants in outdoor containers and baskets, they may require more frequent waterings than they would in the yard or garden.
Disclaimer - This resource is provided for informational purposes only and does NOT reflect current availability. Inventory varies seasonally, so we cannot guarantee that every plant will be in stock at all times - please contact your favourite GardenWorks location directly for current availability. It does not include our entire inventory of plants, so be sure to visit GardenWorks to see varieties that may not be represented on this list.