A fortnightly series first published in the Weekend Gardener and reproduced here with their permission.

The pretty Moraea polystachya has a long flowering season

We are not noted for autumn colour here. I can’t think that anybody has ever said: “Oh but you simply must go to Taranaki to see the autumn display.” The trigger to deciduous plants to turn is temperature related and we drift so imperceptibly from summer through autumn to early winter, that even plants renowned for their capacity to blaze with colour are usually a disappointment. Besides, we are so verdant and green and our native plants are all so resolutely green that all we can do is to admire the occasional single deciduous specimen. Generally it is inland areas with drier climates and much sharper variation in seasonal temperatures which put on the big displays.

However, our autumn is marked by much smaller, pretty pictures of autumn bulbs. We garden extensively with bulbs. In a large garden with some huge trees, it is the dainty, often ephemeral pictures which give the charm and detail. Autumn flowering bulbs are harder to find for sale because most people don’t think beyond the more common spring bulbs.

Cyclamen hederafolium - the easiest of the species in our climate

At the moment, it is the pink and white Cyclamen hederafolium, blue Moraea polystachya (autumn peacock iris), a rainbow of colours in the ornamental oxalis, bold lilac colchicums (often incorrectly referred to as autumn crocus), the real autumn crocus and the beautiful hybrid sarniensis nerines which are carrying the season in the rockery. Out on the roadside, the belladonna lilies are in bloom. Some, like the colchicums, do not flower for long but are very showy. Moraea polystachya is a gem of a bulb. It flowers down the stem so it has an exceptionally long season stretching into months rather than weeks. It can seed down but is easy enough to thin out if necessary.

Cyclamen hederafolium (formerly known as neapolitanum) is the easiest and most reliable of the species cyclamen. It too has a long flowering season, followed by attractive, heart shaped leaves with white markings. It combines very well with black mondo grass and in places we have English snowdrops (galanthus) to come through in late winter, extending the seasonal interest amongst the cyclamen foliage.

Top tasks:
1) Cut off all last season’s leaves on the Helleborus orientalis and remove them to the compost heap. We have done this for many years now, following the advice from Terry Hatch at Joy Plants. It removes any build up of aphids and it means that the flowers are highly visible as they come through with just delicate new leaf growth. As the season progresses, the new foliage takes over and fills the whole patch. Timing is important – if you leave it too late, you have to trim carefully around all the emerging flower stems.
2) After raking off the hellebore foliage, I will weed out the rash of germinating seedlings and then cover the whole bed with a mulch of compost to a depth of about 3cm. This feeds the soil and discourages weeds. Hellebores are one perennial that is best left undisturbed. It is better to raise seed than to try and divide existing clumps. They can sulk for years before recovering.

The Nerine sarniensis hybrids are a real autumn feature in the rockery