Most indoor plant advice is written for the northern hemisphere, which is why so much of it quietly fails here. Sydney gives us humid, hot summers and short, mild winters, and your plants respond to that rhythm whether or not you do. This is what we tell people who come into the greenhouse at Mortdale, season by season.
Summer (December to February)
This is the growing season, and the one where most plants are lost, usually to kindness. Heat makes soil dry faster, so watering frequency goes up, but the rules do not change: feel the soil first, water only when the top few centimetres are dry, and water thoroughly until it runs from the drainage hole.
Move plants back from windows that catch harsh afternoon sun. Glass magnifies heat, and a monstera that was happy in October can scorch in January. Sydney's humidity does most of the work that misting claims to do, so if your plants look stressed in summer it is far more likely to be light or heat than dry air.
Summer is also the right time to feed. Actively growing plants use nutrients; dormant ones do not.
Autumn (March to May)
Growth slows, and your watering should slow with it. This is the single most common mistake we see: people keep to a summer schedule into April and end up with root rot. Autumn is a good moment to repot anything that has outgrown its home, so roots settle before winter. Choose a pot only one size up, a plant swimming in soil holds water it cannot use.
Winter (June to August)
Sydney winters are mild, but light drops sharply and days are short. Expect little to no new growth, and cut watering right back, many plants need it half as often as in summer. Stop feeding altogether.
Move plants closer to windows to catch what light there is, and keep them away from heaters, which dry leaves out fast. If a plant drops a few leaves in winter, that is usually normal, not an emergency.
Spring (September to November)
The best time of year for indoor plants. Growth returns, so resume feeding, refresh tired topsoil with fresh potting media, and prune anything leggy. If you have been meaning to propagate, now is the moment.
The three things that matter most
1. Water by feel, not by calendar
A weekly schedule ignores season, pot size, light and soil. Put a finger in the soil. If it is damp, wait.
2. Light is not negotiable
Most struggling houseplants are simply in a dark corner. Bright indirect light, near a window, out of direct sun, suits the majority of indoor plants. If a spot is genuinely dim, choose a plant suited to it rather than fighting the room.
3. Drainage beats everything
A drainage hole is not optional. Decorative pots without one are fine as covers, but keep the plant in a nursery pot inside.
Common problems, quickly
- Yellow lower leaves: usually overwatering. Let it dry out more between drinks.
- Crispy brown edges: usually underwatering, or heat and draughts from a heater or air conditioner.
- Long, stretched stems: not enough light. Move it closer to a window.
- Sudden leaf drop: often a change in conditions, a move, a cold snap, or a draught.
If something is not thriving and you cannot work out why, bring a photo into the shop at 25 Pitt Street, Mortdale. It is usually one of the four problems above, and it is almost always fixable.
