Dahlia
Also called Garden dahlia.
| Light | full sun |
|---|---|
| Water | Every 3 days in the growing season, every 30 in winter |
| Humidity | medium |
| Difficulty | moderate |
| Height | Up to 110 cm (43 in) tall |
| Pets | Cats toxic, dogs toxic |
Source: ASPCA Animal Poison Control, toxic and non-toxic plants, Dahlia entry.
Toxic to cats and dogs if chewed. Toxic to cats, dogs and horses. The toxic principle is unidentified and the effects are mild, being stomach upset and skin irritation. Keep it where an animal that eats houseplants cannot reach it, and speak to a vet if one does. In South Africa telephone the Poison Information Helpline on 0861 555 777; in the US, the ASPCA Animal Poison Control Center on (888) 426-4435.
Dahlias are Mexican tubers and they are frost tender, so the calendar is really a frost calendar. In the north the stored tubers are started in pots under cover in early spring, from about February, planted straight into the ground in mid to late April, and put outside in late May or early June once the frosts have gone. Seed for the bedding kinds is sown in March or April. In South Africa the tubers go in through the spring and early summer, and a November planting gives flowers by February. Feed and water hard once they are growing, stake the tall ones at planting time, and keep cutting. Where winters are wet or hard, lift the tubers after the first blackening frost, dry them off and store them somewhere cool and frost free.
Ailments observed
| Holes chewed in the leaves | Slugs on the young shoots in spring, then earwigs in the flowers later. Protect the shoots as they emerge, which is when the whole plant can be lost overnight. For earwigs, an upturned pot of straw on a cane catches them. |
|---|---|
| It will not flower | A plant fed with nitrogen, or one never stopped when young. Pinch out the growing tip above the third pair of leaves to make it branch, and switch to a potash feed. Deadhead down to the next bud, not just the flower. |
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