Blue flowers are a rarity in nature, although many gardeners have had some experience with mophead hydrangeas in acidic soils, the weedy grape hyacinth and spring primroses of the same hue.
And then there are those ‘true blue’ perennials that are notoriously difficult to cultivate, with their exacting growing conditions – such as delphiniums, Grace Ward and lily of the Nile, and the fussiest yet most beautiful of them all, the blue Himalayan poppy, with its papery, electric blue petals, which must not be allowed to bloom in its first year after planting or it becomes a one season wonder.
Blue summer flowers are not hard to come by, but aren’t you getting just a little tired of lobelia, ageratum and the odd petunia?
While conifers such as Colorado blue spruce, Blue Star Juniper and Blue Gem have been providing reliable displays of blue needles for years now, there really isn’t much new in that department, either.
So I thought I would introduce you to four novel plants that do offer something unique in this hue – including a fern, a variegated California lilac, a late-flowering deciduous shrub and a houseplant for those of you enjoying the ‘great indoors’.
• Blue star fern – we’ve had a blue fern introduction before in the form of peacock fern, but it was actually a spikemoss. The blue star fern lives up to its name with dusky blue coarse lobes that actually tolerate morning or late afternoon sun.
It can be grown as a houseplant in a room with at least bright indirect light or put out on the patio as a container specimen – but it must be overwintered indoors, as it is frost tender.
• Beyond midnight blue spirea – a new cultivar of a late summer-blooming deciduous shrub, the sage-scented foliage is deer resistant and the rich blue flowers are irresistible to butterflies and hummingbirds. It is both sun and drought tolerant once established and the compact growth habit (24-30 inches tall and wide) makes it easy to place in most landscapes.
• Cool blue – An eye catching variegated California lilac with smaller leaves generously edged in a creamy-white, which don’t seem to scorch or burn, even in hot exposed sites.
The flowers are a slightly paler blue than the most common cultivar, Victoria, but that just seems to add to the overall appeal.
The most interesting aspect of this new introduction is its incredibly slow growth rate (California lilacs are notorious for outgrowing their allotted space in the garden), as the specimens I had in stock only seemed to put on a few inches of new wood.
So maybe you finally do have room in your garden for this popular evergreen shrub.
• Blue Kandy – normally I don’t pay a lot of attention to houseplants, but this Persian violet literally stopped me in my tracks.
The huge flowers are an amazing true gentian-blue with a contrasting yellow center and it only takes three to four blooms to entirely cover a standard plant.
This African native requires little but regular deadheading, average room temperatures, bright indirect light and evenly moist (but not saturated) soil.
The sheer size of the individual blooms and their intense colouring is bound to impress your fellow gardeners.
– By Mike Lascelle, a local nursery manager and gardening author.