Common name: Trailing Petunias
These are a relatively recent addition to the Petunia range and they are generally treated as a half hardy perennial in the UK.
They are quite tolerant to wind and rain, and provided they are deadheaded regularly, the profusion of self coloured and veined flowers will flower until the onset of frost, after which, they should be lifted, potted up, and placed under the greenhouse bench for the winter.
Surfinia © is a registered trademark, and as such propagation is technically illegal, however it is generally assumed that one can propagate plants for their own use.
Feed weekly and regularly deadhead faded flowers.
To encourage bushier growth,pinch out the growing tip just above a leaf joint at planting out time.
Aim to leave 2-3 pairs of leaves.
If growing from purchased plug plants it is often worth while if the plants are large enough, to pinch out the growing tip and reroot it / them in a propagator to increase stock.(see method below)
If planting in containers one plant should be sufficient for containers up to 200mm (8") diameter, larger containers may require 3-5 plants.
As with most other Petunia, they require a light well drained soil in a sheltered sunny spot.
Water over wintered plants and place in a warm spot, circa 13°C (55°F) to encourage new growth.
Sow seed in pots/trays of seed compost and germinate at a temperature of 21 °C (70°F).
Germination should take around a week.
When seedlings are large enough to handle, prick out into 70mm pots of potting compost.
Gradually harden the plants off by subjecting them to cooler conditions until planting out time in May, or when all fear of late frosts has past.
Surfinias,as mentioned above, are produced from cuttings under copyright, and seeds can not be purchased commercially.
One can sometimes get reasonable success from saved seed collected after flowering,but the plants may not come true to variety.
Take 50-75mmmm (2"-3") long tip cuttings.
Cut the stem under a leaf node, and remove the lower leaves to expose approx 25-50mm (1"-2") of stem.
Dip the stem in a rooting powder/liquid, and insert in to pots/trays containing a 50-50 peat* and sand mixture.
*Multi-purpose compost can be used in lieu of peat and sand.
Maintain a minimum temperature of 10°-13°C(50°-55°F) when rooting the cuttings, a little bottom heat can be a distinct advantage at this stage.
Rooting should take place in about 10-14 days.
When rooted, pot on into 75mm (3") pots of potting compost and gradually harden the plants off by subjecting them to cooler conditions,(circa 13°C (50°F),
Growing in too warm conditions will result in soft leggy growth.
Grow on until planting out time in May, or when all fear of late frosts has passed.
Keep the compost fairly moist, but not waterlogged.
Yellowing of the leaves during the early growing stages is probably due to the plants being too wet.
Avoid getting the foliage wet for prolonged periods particularly overnight, and this will help to keep Botrytis and Mildew diseases forming.