Most roses have deep root systems and because of this many varieties do not grow well in pots and containers,
However,this situation has been eased in recent years with breeders breeding cultivars to fill this niche in the market.
Here are a few suggestions to help you to select varieties / cultivars that are suited to containers.
For containers that are a minimum of 200-400mm (8”-16”) deep, consider using Patio or Miniature roses.
For containers that are are 300-600mm (12”-24”) deep or over,consider Compact groundcover or Climbing roses.
Half standards need pots of at least a similar depth, but with a base that has a larger surface area to increase the pot stability, particularly if they are situated in areas exposed to high winds.
For the best results grow plants in as large a pot or container as you can, this not only gives greater compost volume, but can also increases the stability of the container.
Type of Container:
Container may be made of wood, metal, concrete, stone, plastic or clay.
Plastic fares better in cold climates.
If using clay pots in such areas, ensure that they are frost resistant.
Clay containers will provide cooler condition for the roots during hot weather.
If using plastic containers, choose light coloured ones, rather than dark, as these heat up faster.
Locating the container:
After choosing the container and before filling it, decide on a position for the container as it may be too heavy to move once filled.
Also when positioning the container remember that roses love sunshine and should receive sun for at least half the day.
Ideally position the container so that the roots are shaded for part of the day, but the plant is left in full sun.
Keep pots off the ground to ensure good drainage.
This can be done by sitting on bricks or purpose made feet.
As an alternative, rest it on a bed of gravel.
Filling / Planting up the container:
Bare rooted plants should be planted around Week 42, containerised plants can be potted up at any time.
When filling the container, firstly place a layer of rocks, gravel, or broken clay pots in the bottom of it as a drainage layer.
Do not use polystyrene as a drainage layer, as this will potentially lighten the weight of the pot making it more susceptible to being blown over.
When filling the pot use a loam/soil based compost to the equivalent of JI3
In recent years good loam is becoming more difficult to get hold of, so as a substitute, use a mixture of home made compost and or farmyard manure mixed with a good quality potting compost.
Fill the container about two-thirds full with compost, then spread the roots of the bare rooted plant over a slightly mounded heap of compost.
Finally, top up the container with compost, pressing the compost between the roots with your fingers as you go.
The finished soil surface should be slightly below the bud union (where the rose is grafted onto the rootstock).
Water the plant in thoroughly on completion.
Top up the container with compost if the watering has caused settlement.
To deter moss growth and to give a more aesthetic look to the container, spread a layer of small gravel or clay pellets over the surface of the compost.
If doing this, ensure that the finished surface is slightly below the bud union (where the rose is grafted onto the rootstock).
Do not allow the compost to dry out or the plants will become prone to mildew.
Top dress circa Week 16-18 with a proprietary Rose fertiliser, and every four weeks thereafter during the growing season but do not feed after Week 35.
To do so will encourage soft growth that may be damaged in winter.
Annually in spring, replace the top few inches of compost with a fresh layer.