Top tips for keeping that much loved Christmas plant alive. We've tested a plant sensor and mixed it up with some good old gardening knowledge...
Bought a Mexican flower? Be sure to get a Manuel.
It’s the time of year to plant Dahlias , a genus of bushy perennial plants native to Mexico. There are around 30 species and 20,000 cultivars of dahlias, so if classification of dahlias is nacho forte, read on.
If you want to know more about successfully growing Dahlias, then check out our Manuel on How to Grow Dahlias.
Classification: as easy as Juan, two three.
Dahlias are classified both by size - which varies from mignon (5cm in diameter) to giant (over 25cm) – and by the size and form of their flowerheads. These include:
- Decorative dahlias, a class that is further subdivided into formal decorative dahlias, which have nearly flat ray florets in a regular arrangement, and informal decorative dahlias, whose florets are more twisted or curved, and may be arranged in a more irregular way.
- Cactus dahlias have ray florets that are downward curled. This may be for up to half of their length (semi-cactus dahlias) or more (straight cactus dahlias). Incurved cactus dahlias are similar to straight cactus dahlias but the petals have a more pronounced curve towards the centre of the flowerhead.
- The ray florets on a lacinated dahlia are split at the ends and twisted, giving a fringed effect.
- Ball, miniature ball and pompon dahlias all have a similar ball shape, but the ray florets on a ball dahlia will be inward curled for around half their length, compared to entirely involute florets on a pompon dahlia.
- Waterlily dahlias, in contrast, are flat to saucer shaped, with broad, slightly cupped florets.
- Single dahlias have a single row of uniformly spaced ray florets around a central disk.
- The ray florets on an Anemone dahlia are arranged around a protrusion of tubular disk florets at the centre.
- Collarette dahlias have a single row of ray florets around an inner ring of shorter florets.
- Orchid dahlias have a single row of ray florets that are inward-curling for at least two thirds of their length.
- Peony dahlias have multiple rows of ray florets around the central disk. Those nearest to the disk are often curved.
- The florets on Stellar dahlias become more mature towards the outer edge of the flower.
- Novelty dahlias are any flowers that do not fall under the classifications above.
Lets taco bout planting
- Plant in spring after the risk of frost has passed. You can either plant well-established plants or tubers, which should be placed 10-15cm below the surface of the ground, with the eyes pointing upwards. Space dahlias at intervals of at least half of their maximum height. Don’t overwater, as tubers are vulnerable to rot.
- Fertilise with high potassium liquid fertiliser from mid-summer to early autumn.
- Pinch out the growing point and deadhead as flowers fade to encourage a good shape and promote flowering.
- In mid-autumn – after the first frost – cut stems back to 15cm, lift the tubers, brush off soil and leave upside down to dry naturally. Dust with fungicide, pack in boxes of dry sand and store in a frost-protected location.