Water-wise roses and water-wise tactics for roses
Rose gardeners will do everything they can to keep their roses going during a drought, and the past two seasons have tested their ingenuity and the roses’ ability to survive. A surprising discovery is that roses can survive on less water than we think. They might not look lush after days of dry heat and no water, and their leaves will hang, but given a good watering or drenching rain they rally very quickly. Roses that are more drought-tolerant have specific characteristics. Generally, they will be spreading groundcovers or neat shrubs.
The aspects to look out for are:
- Natural spreading growth that shades the root zone.
- Medium-sized leaves that are leathery and have a resistance to
- Relatively short flowering stems that flower after the
development of 6-7 leaves. Stems with 10-15 leaves
take up much more water for a longer period before they mature. This
does not mean that tall roses can’t be water-wise, but they should be built up with many short stems.
- Semi-double flowers with firm, leathery petals that don’t easily dry out.
Some examples of water-wise roses are ‘Waterwise Blush’, ‘My Granny’, ‘Rosy Cheeks’, the ‘Ayoba’ range, ‘Salmon Sunsation’, ‘South Africa’, ‘Bella Rosa’, ‘Deloitte & Touche’, ‘Bienkie’, ’Bridget’, ‘Joburg Garden Club’, ‘Pink Profusion’, ‘McHardy‘, ‘Easy Does It’, ‘Memoire’, ‘Avril Elizabeth Home’ and ‘Winter Sun’.
A special case
‘Remember Me’ was introduced last year, and its performance made us realise that we had a new kind of rose. It falls between a formal hybrid tea and a spreading shrub rose, with powerful roots that spread wide and deep. The pink flower incorporates shades of misty grey and ochre in the centre, and the flower develops from a pointed hybrid tea bud into a full nostalgia bloom with incurved petals. It grows to shoulder height and spreads 2m, performing with ease as a specimen rose or among other bedding varieties
There are more of these roses in the pipeline, which we plan to call ‘Stamina Roses’ as a new category of roses. We will be introducing them in September, with a preview of some varieties at our Autumn Rose Festival at Ludwig’s Rose farm on 21 March.
Growing roses the water-wise way
Start with the soil: Plant roses in soil prepared to a depth of 30cm and enriched with organics, like compost and rotted kraal manure, as well as slow-release fertiliser, like Vigor-Longer. Friable soil (it feels spongy) allows water to easily penetrate to the roots, so that every drop of water counts.
Not good: Compacted soil is a water waster because water runs off without reaching the roots. Always check for compacted soil, which is hard to penetrate with a fork. During the growing season, spike the soil deeply around the rose to allow in water. In autumn or winter, redo the beds, adding in lots of organic material. It is okay to disturb the roots when the roses are dormant.
Nurture the roots: Cutting off too many leaves and stems puts strain on the roots under high-heat conditions, not to mention sunburn on the stems. Leaves shade the roots and keep the plant cool. When too many leaves are removed, the flow of nutrients to the roots is reduced, which sets them back.
Not good: Root competition from nearby creepers, shrubs and trees slurps up water and nutrients meant for the roses, especially in a drought. Digging down next to the rose allows you to check root activity. Where there are aggressive roots, lift the rose, plant it in a container and sink the container back into the ground. Alternatively remove the offending shrubs or creepers and replace them with less aggressive varieties.
Mulch is a must: aA 2cm layer of light-coloured organic mulch, like dried leaves, bark chips, pine needles or nutshells, spread around the roses shades the surface of the soil from direct sun, keeping the roots cool and reducing transpiration. Light-coloured mulch reflects the light and heat away from the plants.
Not good: Don’t make the layer too thick because this doesn’t allow water to reach the soil. Also, don’t pile up mulch around the stems. Leave a gap (like the hole in a doughnut) so that water and fertiliser can easily penetrate it.
Grey water is better than no water: Roses can survive, and some gardeners even report that that thrive on grey water, which is recycled water from the bath, shower, basins and washing machine. Use detergents and soaps that are biodegradable and have a lower salt content. Roses that receive 10 litres of grey water a week will still grow and flower. Use fresh or municipal water once a month, if possible, to wash away any accumulated salts.
Not good: If you are running water directly from the washing machine, bear in mind that the first discharge is the dirtiest and contains the most detergent. Move the hose around so that the same roses don’t always receive the first discharge of water and soap.
Control red spider: Red spider breeds in drought-like conditions when the sap flow is sluggish and more concentrated. The mites suck the sap out of the leaves, which fall off and expose the stems to direct sun. Leaves appear mottled yellow and green, finally turning yellow or brown and dropping off. Spray with Milbeknock, drenching the underside of the leaves, and repeat a week later.
Not good: Spraying with diluted sunlight dishwasher liquid can strip the protective waxy coating, which regulates transpiration and gives protection against the sun, off the leaves. Only spray with recommended red spider mitecides.
Don’t fertilise: Fertiliser stimulates the rose to grow, which means that it needs water. Delay fertilising until good rains are received or water restrictions are lifted.
Not good: Applying fertiliser without sufficient water can kill a rose.
Sink a two-litre cooldrink bottle without its cap next to the roses, so that the opening is at root level. Cut off the broad base of the bottle so that it can be easily filled with a bucket, hose or watering can.
Place roses in containers on a saucer containing bark chips so that the water drains through the pot but isn’t wasted. The bark chips keep the base out of the water but capillary action will draw the water up when it is needed.
To prevent water running off sloping rose beds, place concrete rings around the roses, on the downside of the slope. By placing the rings half into the soil, they will catch the water for the rose.
Only use drip irrigation for roses if it is laid on top of the bed and is easy to monitor for blockages. Faulty irrigation with blocked sprayers results in many roses dying.
When watering, rather give a bucket of water a week to a rose than a daily dribble every day. That’s because a deeper watering will reach the roots.
Information from Ludwig’s Roses, www.ludwigsroses.co.za