September in the Garden

Tasks for Spring

August in Christchurch was chilly, with an average temperature of just 6.8°C. Nights often dipped close to freezing, the coldest at -4.5°C, while the warmest day only reached 16.4°C. It was a fairly wet month too, with 91 mm of rain, most of it falling mid-month.

Looking ahead, September usually feels like a real shift into Spring. Daytime highs average around 14°C, nights about 6°C, and while frosts can still sneak in, the longer, sunnier days encourage everything in the garden to burst back into life.

In September it feels like Spring has truly arrived—bulbs are blooming and deciduous plants are bursting into life; growth is everywhere. With the changeable weather and the risk of late frosts, it’s a busy month in the garden.

Soil & Planting: Prepare ground for sowing and transplanting, clear away winter crops, and finish pruning. Sow hardy vegetables like peas, carrots, lettuce, silverbeet, beetroot, and cabbage. Plant early potatoes and chit main crops for later.

Flowers: Propagate summer perennials (chrysanthemums, dahlias, carnations, petunias) from cuttings. Plant gladioli corms and start begonias in pots. Deadhead bulbs and annuals to encourage more blooms.

Care & Maintenance: Keep weeds in check before they smother young plants. Fertilise and mow lawns regularly. Treat fruit trees for pests and diseases as they flower. Prune spring-flowering shrubs once they’ve finished.

Greenhouse & Citrus: In unheated greenhouses, plant sturdy tomatoes and other tender crops. Feed citrus with Spring fertiliser and prune lightly for shape and airflow.

September sets the pace for the season—plan carefully, protect tender growth, and enjoy the burst of colour and energy in your garden.

Monthly Tips & Tasks from Julian Odering

Thanks to Julian Odering of Oderings Garden Centres for his seasonal insights last month at Garden Life. Julian returns this month to present Tips & Tasks so bring along your gnarly questions — Julian is here to help.

Remember: questions can be posted on HortTalk our online facebook group