Roses don’t need to be re-potted that frequently because they have the ability to regenerate themselves. In winter the many hair roots die and decompose creating natural compost. It is usually very clear when roses do need to be re-potted. They don’t flower or grow as well, the leaves may have a yellow, underfed look and they may also be more prone to disease. This will be due to the fact that the soil in the containers is depleted or has become hard and there is not enough aeration around the roots. Generally, roses can be re-potted every three years and it may also become necessary if a rose has outgrown its container.
An alternative, when it is too awkward to re-pot a particular rose, is to push a strong stick into the potting soil several times, wiggling it around to create tunnels. Fill the tunnels with compost or an enriched potting soil mix. This process also opens up the soil and allows the air and water in.
The potting mix for roses needs to be quite rich. A special potting mix that consists of soil, peanut shells, clinker ash (for aeration) and well-rotted horse, chicken and pig manure is available from all Ludwig’s Roses outlets. If you don’t have access to it, you can make up your own mixture. It should consist of one-third soil, two-thirds coarse organic material plus bone meal or superphosphate. If you use sandy soil then also add a water-retaining material. The organic material can consist of a mix of peanut shells, coarse outdoor potting soil, rough homemade compost or the fibrous material obtained by soaking compressed palm peat bricks.
- Cut back the rose by half to reduce water loss.
- Lay the pot on its side and ease out the rose.
- Shake excess soil off the roots and remove broken roots.
- Wash the pot with Jeyes fluid or Sunlight dishwashing liquid.
- Half fill the pot with the new soil mix and position the rose on the soil. There should be a 5 cm space between the soil level (the rose at its previous level) and the top of the pot.
- Fill in around the rose with new potting mixture, working it down the sides of the pot and lightly firming it. Make sure the bud union is covered with potting soil.
- Cover the surface with mulch. This keeps the soil cool and prevents the daily watering from compacting the soil.
- Water well, so that the water drains out the bottom of the pot.
- Keep the rose out of the full sun for about a week (or until you feel it has settled in).
- First prepare the new position. Dig a hole, at least 50 cm deep, and mix compost, Vigorosa and bone meal or superphosphate into the soil that came out of the hole. (If several roses are to be transplanted then it is better to prepare a bed instead of individual holes.)
- Fill the hole with water, let it drain out and then return the soil to the hole.
- Cut the rose or roses down by half.
- Push the blade of a spade into the ground in a full circle around each rose bush, about 20 cm from the centre of the bush. This is to loosen the ground and cut the anchoring roots. Once these roots are severed then slide in the spade and carefully lift the rose out of the ground.
- If there is serious resistance it means some of the major roots have not been cut. Instead of tugging on the bush to release it, use the spade to cut the roots cleanly.
- Shake the soil off the roots, prune away broken roots and dead wood and, if possible, plant the rose in its new position immediately.
- Plant the bud union at soil level, firm down the soil and water well. Follow with weekly watering.
The rose will start growing but the leaves will not lead to new blooms and it will need pruning in July.