Now is the time to prepare your garden for the summer ahead. After a difficult, cold and wet spring at least we can rejoice that our state’s reservoirs are full!  So, how should we care for our roses during summer?

Watering

The most important ingredient for roses in summer is water. Generally, established roses need an average of 20 to 30 litres of water for each rose per week.  It’s essential that a rose is well hydrated prior to expected heatwaves, where the temperature is above 35°C on average. If severe heat is forecasted in the week ahead, you should increase the rate of watering to 30 to 40 litres per plant. If a rose dries out, it is difficult to get it to recover quickly. Water in one weekly application or, at most, twice per week.  In most cases, good deep soakings, early in the morning, in one weekly application or, at most, twice per week is far better than small amounts daily.  Mornings are preferable to evenings, as damp humid conditions can lead to fungal diseases.
These watering recommendations assume you have a substantial layer of mulch. Without mulch, you’ll need twice the volume of water per plant.
Finally, your pots and containers will require monitoring and watering as they can dry out quickly in summer. Give pots a good watering (until it runs from the bottom of the container) every two days and try and shift your pots under partial shade during heatwaves.

Mulch

One of the most important jobs is mulching in the summer months. A good layer of mulch performs three key tasks:

Neutrog’s ‘Whoflungdung’ is a certified organic mulch which has revolutionised mulch in Australia. This mulch is biologically activated, nutrient rich and weed free. It comes in convenient 20kg compressed bales and can be easily spread.
On rose beds ‘Whoflungdung’ should be applied between 5cm (if topping up areas already mulched) to 10cm thick (if applying for the first time). Keep at least 10cm radius from the base of the rose. Apply water after application to settle the mulch into its position.Flowering

Providing the spent blooms were removed following the first flush in spring, another bountiful blooming period will coincide with the Christmas/New Year period.
Once this is over, we have two options. The first is to leave the spent blooms on the bush and reduce the watering a little, providing just enough to keep the plants alive, but not thriving – effectively placing them into a summer hibernation.  They can then be stirred back into strong growth with an application of Neutrog ‘Sudden Impact for Roses’ and a summer trim in late February or early March.
‘Sudden Impact for Roses’ is an organic based fertiliser recommended by the Rose Society of S.A.  It provides a full range of plant nutrients in a slow-release form together with water-soluble nutrients to maximise performance.
The second option is to keep the rose flowering with continuous removal of spent blooms, with plenty of water and applications of liquid ‘Sudden Impact for Roses’ every two weeks in January.
It is to be expected that the flowers in January, February and early March will generally be smaller than the autumn flushes. This is heat related. In addition, due to high UV readings, dark coloured roses, such as red roses, can show scorched petals after very hot, sunny days. Like us, some roses can burn under these conditions. Temporary shade can prevent this occurring if desired.

Fertilising

If you want your roses to thrive during summer, an application of ‘Sudden Impact for Roses’ soon after Christmas is recommended. This can be applied as pellets if you have a sprinkling system or as a liquid if you have drippers.
Any underperforming roses can be given an application of Neutrog’s ‘GOGO Juice’ every fortnight. This is essentially a pro-biotic for your soil and plants which is rich in beneficial bacteria and other microbes to assist in encouraging the plant to recover.  If it does not recover, it may be near the end of its natural life, generally 20 years, and could be dug out in autumn to enable a new rose to be planted.
If you have put your roses into summer hibernation, start applications of heavy watering early in February and then fertilise with ‘Sudden Impact for Roses’ in mid to late February. A summer trim should follow two weeks later to ensure the rose is set up for an abundant autumn flush in around 55 days after the trim.
A word of caution is required here because the operative procedure is “summer trimming”.  It is sometimes wrongly referred to as summer pruning and the inexperienced grower must resist the temptation to cut too heavily.

Pests and Diseases

Given our hot, dry, low-humidity summers, most fungal issues disappear and pests such as Aphis and grubs also “back off”.  Spider Mite may be an issue and when present, lower leaves close to the ground may pale in colour. Remove a leaf, turn it over and watch carefully. If insects, the size of pepper start moving around and/or a fine web is evident, Spider Mite are present.
Organic oils (such as Eco-Oil or Eco-Neem) or one of the natural sprays (such as Natrasoap) can be used to control bad infestations – don’t use strong, toxic insecticides.
Water sprayed upward from under the leaves can also assist with the removal of early infections.  Spider Mite live under leaves and don’t like to be wet.
Summer is all about the weather. Plan ahead based on the weather forecast for the next 7 days in relation to watering and possibly using shade protection.
If you follow these guidelines you will continue to get the best from your roses.