Plant taxonomy classifies Blue Princess holly as Ilex x meserveae 'Blue Princess.' Ilex is the genus name for holly. The x meserveae indicates that the shrub is one of the Meserve hybrid plants. 'Blue Princess' is the cultivar name. A popular male pollinator is the aptly named "Blue Prince holly" (Ilex x meserveae "Blue Prince"). You'll sometimes hear these shrubs referred to as being part of the "blue holly" group.
Characteristics of Blue Princess Holly
While it's possible for Blue Princess and Blue Prince holly to top 12' in height at maturity, these shrubs, even with just minimal pruning, are easily kept at a fraction of that height. Prune to the desired shape and dimensions. Unless you're using them in a hedge, these plants look best when the pruning isn't too obvious. To accomplish this, stagger the depth of your pruning cuts. For more on pruning holly, see below.
The shrubs' leaves are a glossy, dark green color and moderately spiny. Their inconspicuous flowers bloom in spring (and sometimes again in fall). Blue Princess holly berries are bright red.
Planting Zones for Blue Princess Holly:
Blue Princess holly can be grown in zones 5-8.
Sun and Soil Requirements for Blue Princess Holly:
To keep the soil sufficiently acidic around Blue Princess, use "Holly-tone" or a similar product as a fertilizer.
Best Time to Prune Blue Princess Holly
When is the best time to prune hollies? Well, you may have to juggle some priorities and make a compromise. Some folks prune in early winter because they want to bring the cut stems with their holly berries into the house and enjoy them inside. Others prune later in winter because they prefer their display of holly berries outside.
Of course, any floral buds (whether on a male or female shrub) located on the branches you prune off are buds that won't open next year, resulting in reduced pollination and fewer holly berries (hollies bloom on old wood).
Uses for Blue Princess Holly
Blue Princess hollies, with their evergreen leaves and trademark holly berries, are fine winter-interest shrubs and certainly attractive enough to serve as specimens in the winter landscape. To ensure optimal enjoyment of these qualities during the long winter, plant Blue Princess hollies near your main entrance, perhaps in a foundation planting. Their evergreen leaves also make them an option for those seeking hedge plants that will provide color year-round.
In Quest of Holly Berries - Telling Blue Princess Apart From Blue Prince Holly
These bushes are dioecious. Only Blue Princess can develop the trademark holly berries, and it needs a male pollinator to do that. But the question is, if you're looking at a blue holly that has no holly berries, how can you determine whether it's a Blue Prince holly or an unfertilized Blue Princess? The answer lies in their respective flowers.
Holly Berries, Blue Holly and Other Types of Holly
While it is necessary to plant a male pollinator such as Blue Prince in order for a female to produce holly berries, it is not necessary to maintain a 1:1 male-female ratio. That is, one male such as Blue Prince will suffice as a pollinator for several females.
If you don't particularly like the look of evergreen hollies such as Blue Princess but still desire holly berries, plant winterberry, instead. Winterberry is a deciduous bush and its display of holly berries, under the right conditions, is superior to that on the evergreens.
Branches festooned with red holly berries may be pruned before the holidays, so that the clippings can be brought inside and used for decorations (but see above).
The "blue" in "blue holly" derives from the degree of darkness in the leaves: some term this color "blue-green." Three of the most popular blue holly male-female pairs are as follows:
- Blue Boy (Ilex x meserveae 'Blue Boy') and Blue Girl (Ilex x meserveae 'Blue Girl')
- Blue Stallion (Ilex x meserveae 'Blue Stallion') and Blue Maid (Ilex x meserveae 'Blue Maid')
- And the shrubs discussed in the present article, Blue Prince and Blue Princess
Other Types of Holly
There are many other types of holly:
Nellie Stevens is a tree-form hybrid holly popular in the southern U.S. Northerners seeking a tree-form holly are better off planting the somewhat hardier Ilex opaca 'Mac's Prince,' a type of American holly.
You may have seen Hetz Japanese holly (Ilex crenata 'Hetzii') without even knowing it! The foliage of Japanese holly can easily be mistaken for that of boxwood. My favorite Japanese holly is Sky Pencil (Ilex crenata 'Sky Pencil'), which assumes an extreme columnar form.
English holly (Ilex aquifolium) is the holly invested with so much Christmas lore.