June is the month when problem roses get a second chance. Rose grower Ludwig Taschner gives tips for getting your roses back into shape for the summer.
The rose season is coming to an end and it’s a good time to look critically at your roses. Did they flower and grow as you hoped they would, or were some disappointing?
There are many reasons why roses don’t thrive. It could be too much shade, root competition from other plants, compact soil or just being in the wrong place?
June is the ideal month to fix the roses because they are going dormant, which means they aren’t as stressed if their roots are disturbed by transplanting or reworking the soil. The cooler weather is also kinder, as there is less heat stress and less evaporation from the leaves.
The first step is to do a bit of detective work. Dig a hole, about 30cm deep next to the rose bush.
What do you see?
If the soil is completely dry from top to bottom of the hole, the roses are not getting enough deep regular watering. This is likely the result of compact soil that does not allow the water to penetrate. The quality of the soil will be the best indicator.
This rose was in very compact soil and the roots grew upwards towards water and air.
Solution
Water the bed well the night before. Then dig in compost and organic material such as peanut shells, milled bark, dried leaves and compost into the soil around the rose to a depth of 30cm. The more organic material added to the soil, the spongier the texture will be, which allows water to penetrate easily and air to reach the roots.
Poor drainage
If the soil in the hole is very wet and doesn’t drain, or if water stands at the bottom of the hole, growth suffers because there is not enough air to the roots. Poor drainage needs to be fixed because the roots will eventually rot.
Solution
The best solution for poor drainage, or poor, shallow soil, is to make a raised bed. Cut down the roses by a third, and dig them out, making sure to keep a ball of soil around the roots. Put them to one side, in the shade.
Build up the bed by bring in plenty of organic material (compost, etc) so that the level is raised by at least 30cm. Adding a built up border (bricks, stones etc) will help retain the soil. Replant the roses and water well.
Root competition or too much shade
If the hole you dug is full of roots, other than those of the rose, it is a problem of root competition. The roots may be from nearby trees, like the conifer behind, as well as from close growing shrubs and perennials, which affect the performance of roses. Trees and shrubs have aggressive root systems that take up water and nutrients meant for the roses.
Roses planted too close to trees may also be deprived of sun as they need at least six hours of sunshine to grow and flower well.
Solution
Root competition can be solved by transplanting the rose elsewhere or by digging up the rose and planting it in a large pot which is then sunk back into the soil. The edge of the pot should be level with the soil surface. The pot prevents the roots from encroaching. Lift the pot every three to four months to make sure nearby roots haven’t grown into the pot.
For roses in the wrong position, first prepare the soil in the new position, making sure it receives at least six hours of sun a day or consider planting the roses in containers.
Tag the roses with their names. Once they have been cut down by a third it’s hard to tell which rose is which.
Dig deeply in a circle around the rose bush, pushing in the spade to sever the roots. Once the roots are severed, lever the bush out with the spade. Do not pull out the bush. Trim off any broken roots and replant the rose in its new position. Water well.
Over time the bud union can become submerged under new layers of compost or the soil leaches away, leaving the bud union above the ground. The ideal position for the bud union is just under the soil surface. Dig up and replant the rose at the right level.
For more rose growing advice visit www.ludwigsroses.co.za
TEXT: Alice Coetzee
