Care for Hydrangea
Hydrangeas can be planted all year round. Plant them in a position that provides shade throughout most of the day, some morning sun is tolerable. The soil will need to be kept moist at all times. You will notice the leaves hanging limp if they are thirsty, this indicates that you should water immediately. Hydrangea paniculata, arborescens and quercifolia varieties can tolerate more sun than the macrophylla varieties.
All hydrangeas are deciduous and it is normal for them to succumb to fungal attack on the leaves when conditions are conducive. Fungal spores occur naturally in the air. When weather is wet and humid causing the leaves to remain moist for extended periods of time, the fungal spores proliferate on the leaves. As part of a hydrangeas normal seasonal cycle, when the previous seasons leaves reach their maturity, they will become spotty and discolored, it is not a problem as these are the old leaves and they will eventually drop off and be replaced by new leaves in Spring time. You will notice some of the stock you purchase around Autumn and Winter to have some of these discolorations on the leaves. Some customers who have never grown hydrangeas become alarmed and report various spots and discolorations they observe on the foliage. I reassure customers that this is normal. The senescing leaves will drop off in winter and fresh new unblemished leaves will begin to emerge in spring. This will continue year after year as part of the normal growth cycle.
If you want your hydrangeas to look perfect all year round, you can try to prevent discoloration by spraying with a fungicide. We use Eco-rose (available through the online store). It is also good practice to water plants at soil level to avoid wetting the leaves unnecessarily during these conditions.
You can achieve a longer or successional flowering period by trimming the spent flower heads off the bushes after the first flowering culmination by late spring or early summer. We do this at the nursery to ensure flowering extends right through till Autumn,
Hydrangeas are a deciduous shrub. It is normal for them to lose most or all of their leaves during winter, particularly in cooler climates such as Victoria. Leaves will initially become discolored and/or get spots on them - this is normal. Do not be alarmed, their leaves will start to grow back in spring.
The hydrangeas are kept in open tunnels to promote airflow. We don't like to spray harsh pesticides and prefer to use a pyrethrum or neem based spray if we notice some bugs. Because the tunnels are open it is only natural that some bugs may fly in and land on the foliage. If you see a bug, please don't be alarmed as it is perfectly natural that they may find a hydrangea leaf or stem delicious! Spray with a pesticide of your choice or even remove the bug with your fingers.
White mophead and lacecap hydrangeas are generally stable in their color, but the pink and blue hydrangea varieties are able to change from one spectrum to another depending on the pH of the soil. An acidic soil containing aluminium will induce coloring within the blue, purple, mauve range of the spectrum, whereas alkaline soil will induce coloring within the pink and red spectrum.
We fertilize the bushes with a seaweed based fertilizer and Manutec Pinking or Blueing fertilizer. These can be purchased through the online store.
Cut hydrangeas back to about 10-20cm in height every winter. This induces bigger flower blooms during the next flowering season.
I found the following video to be very informative: