Plectranthus argentatus

Growing in Pots, Balconies & Indoors

Silver spurflower is grown for its felted silver foliage and makes a fine container and balcony plant. The grower does not rate it as a true houseplant – it wants strong light – but it can hold up on a bright, sunny windowsill.

Quick Details

• Container Size: 7-15 L (2-4 gal)
• Indoor Suitability: Not a deep-room houseplant; happiest on a bright, sunny sill or outdoors
• Best Spot: Full sun to light shade
• Soil & Drainage: Aerated, free-draining potting mix
• Watering in Pots: Modest – let the top dry between waterings; pots must drain freely

Indoors & On the Windowsill

• Houseplant limits: The grower marks it as not a houseplant – away from a window the light is too weak and the silver foliage loses its colour and grows leggy.
• Windowsill growing: On a sunny, bright sill it does well; give it the most direct light you can and turn the pot now and then for even growth.
• Overwintering indoors: It is frost-tender, so in cold climates bring the pot into a bright, frost-free spot over winter and set it back out once frosts pass.

On a Balcony or Patio

• Light & wind: Give it the sunniest spot; walls and paving reflect heat so pots dry fast – check moisture in warm spells. Shelter the soft stems from strong wind.
• Practicalities: A filled pot is heavy once watered – check the balcony can take the load, and stand it where drainage runoff will not be a nuisance.

Choosing the Pot, Soil & Long-Term Care

• Pot & drainage: A 7-15 L pot with strong drainage holes and never leave it standing in a saucer of water, or the roots rot. Terracotta breathes and dries faster; glazed or plastic holds moisture longer.
• Potting mix: A well-aerated, organic-rich mix – potting compost, or peat/coir with perlite or vermiculite.
• Feeding: Potted plants use up their feed quickly as nutrients leach away with each watering, so feed more often than plants in open ground through the growing season. It is a vigorous grower and responds well to a balanced feed.
• Repotting: Refresh the top layer of mix and pot up roughly every couple of years; for perennials, lightly trim the root ball and top growth when you do.

Bloom & Flower Guide

Quick Details

• Bloom Season: Summer into autumn
• Flower Appearance: Small, two-lipped, pale bluish-white flowers carried on upright racemes above the foliage
• Edibility: Grown as an ornamental (mainly for its silver foliage)

Detailed Blooming Overview

Silver spurflower is prized above all for its felted, silver-grey leaves, but in summer and autumn it sends up slim spikes of small pale flowers. They are modest against the foliage yet valued by bees, and add an airy vertical accent.

Flower Characteristics

• Small, lipped white flowers arranged on raceme-like spikes, as the grower notes.
• Held clear of the silvery leaves for gentle contrast.

Bloom Care & Thinning

• Foliage or flower: Pinch out spikes if you want to keep the emphasis on dense silver foliage, or leave them for pollinators.
• Shape: Regular pinching builds a fuller, bushier plant.
• Frost: It is frost-tender, so protect or overwinter it under cover in cold areas.