Author: JM Date Posted:4 May 2018
Is there such a thing as a garden with too many Hydrangeas? ..... I think not.
Hydrangea macrophylla x nigra 'White Knight'
Their tolerance of all the things thrown at them by the Australian climate has made them somewhat ubiquitous in older suburbs and gardens and yes it has to be admitted that many of them are sad and neglected representatives of their species and that their owners should be severely rebuked for allowing such an obliging plant to look so shabby but those that are given a modicum of attention are in no time garnering admiring glances right in the middle of summer when many other shrubs have gone over and gardens as a whole are struggling to impress. The good old hydrangea, ( Hydrangea hortensia or Mop-head Hydrangea) when established, battles through drought , dropping leaves and bearing scorched flowers on the way but hanging in there nonetheless to amaze us the following season when conditions are kinder and their generosity of flower comes to the fore.
Hydrangea macrophylla 'Ayesha'
When used as potted specimens they look impossibly glamorous, evoking memories of the Cote d'azure where they are treated with the respect they deserve. The French use them in pots running down grand stair cases, on terraces or around swimming pools or planted in shady shrubberies where they continue their display well into autumn.
Trying to find a dark blue potted hydrangea is a hard ask when most nurseries use some form of commercial soilless potting mix which, by necessity, is laced with lime. The handsome blues specimens seen in mountain gardens are only attainable if you make your own peat based potting mix. Our own mix is made up of garden loam to which we add a good lashing of peat, homemade compost and sharp sand, a general fertilizer, some Rock Dust and aluminium sulphate or Hydrangea Blueing Powder. If young plants are potted into this mix their future will be one of 'radiant blueness', be forewarned though, in areas with a town water supply Blueing Powder (aluminium sulphate) should be added every year to counter the alkaline water supply which in time will turn any hydrangea pink. You can use Epsom Salts ( magnesium sulphate) to reduce PH also.
Hydrangea quercifolia 'Snowflake'
The great thing about the mop-head varieties is the refined ageing of their flowers. The large heads of what we think of as flowers are in fact bracts which change all manner of different shades as they mature. This depends on the level of shade, the soil Ph and available moisture but whatever the prevailing conditions their effect always seems appropriate for the area and are to my mind one of the highlights of autumn.
If for some strange reason you have developed an aversion to Mop-head Hydrangeas there is a whole tribe of alternate species all of refined character from which to choose. Most of these exhibit the same strong constitution as their maligned cousins and bring a miscellany of different characters and growth habits to the table. Many of them have lace-cap flowers which are tolerant of dryer conditions and a degree more sun than their Mop-head cousins.
Hydrangea macrophylla serrata 'Miyama Yae Murasaki'
Apart from a large number of macrophylla hybrids our collection includes:
Hydrangea quercifolia, quercifolia, Pee Wee, Quercifolia Sikes Dwarf, Quercifolia Alice.
Hydrangea aspera , aspera strigosa
Hydrangea serrata Grayswood, serrata Shiro Fuji, Miyama Yae Muraski
Hydrangea paniculata, paniculata 'Kyushu', paniculata Strawberry Sunday
Hydrangea amomala ssp. petiolaris
Schizophragma sinensis ( a close relative and similar to H. petiolaris)
Among many others.