Cacti

Posted by Fitzroy Nursery on

Cacti are a diverse group of plants and are well-known for their spectacular flowers, dramatic

sculptural forms and their beautiful, often formidable spines. Many have evolved to survive harsh, dry desert & mountain environments, which makes them well-suited for indoors planting. Although many

species can withstand considerable neglect, they will grow better, flower more profusely & live longer if the following ‘rules’ are observed.

WATERING

Watering - Plants should be given a good soaking & then allowed to almost dry out.

This will depend on:

  • Aspect – cacti on a sunny, north facing window may require soaking twice a week in summer, compared to once a month if it is cool & sunless (winter).
  • Potting mix – will need to be open & well-draining. Cacti and Succulent mix is recommended. Never allow pots to sit in a saucer of water.
  • Season – most species like to remain dry over the dormant period (winter). They require most water when they are actively growing (spring & summer).
  • Sunlight – is essential for better shape, flower & spine formation. The spines protect plants from sunburn. Hairy & closely spined species require the brightest light.

Plants on windowsills will grow & flower more symmetrically if they are rotated regularly.

FERTILISING

Slow release fertiliser which is low in nitrogen, is best for healthy, strong growth & good flowering. Only feed when the plants are actively growing (i.e. not in winter).

Larger, fast growing varieties require more feeding than smaller, globular ones.

TEMPERATURE

Most species are tolerant of temperature extremes & will survive cold Melbourne winters as long as they are kept dry. In fact, a cool, dry winter will often promote better spring flowering. (NB.

Melocacti are notable exceptions & are best kept indoors in winter.)

Problems
 Cause
Poor colour (red caps) Poor lighting
Rotting / collapse Over watering
Elongated shape Poor lighting
Scarring Sunburn, mechanical damager
Scale

Spray with Eco or Pest Oil

Mould infections Spray with Eco fungicide. Allow offsets to callous for one week before re-potting
 
Pests and Diseases
Treatment
Red Spider Raise humidity and ventilation (i.e move outdoors), regular detergent sprays
Mealybug  Dab with methylated spirits if minor, spray and/or drench with Confidor if major

 

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