When to plant Phlox in Arid Australia
Arid zone — applies to Alice Springs, Mildura, Broken Hill, Kalgoorlie, Port Augusta and similar areas. Growing elsewhere? Temperate · Cool · Subtropical · Tropical.
Sow annual phlox direct from March to September, scattering the fine seed just 3 mm deep into a raked, sunny bed. In arid gardens this cool-season window suits it well, letting seedlings grow through the mild months and flower before the fierce summer heat. Germination takes 10-20 days, and plants run to about 70 days from sowing to bloom, giving a quick, colourful return. Thin or space them 10-15 cm apart, with rows 20-30 cm, as a dense stand supports itself and puts on a solid sheet of colour. Phlox dislikes root disturbance, so sow it where it is to flower.
Sowing calendar — arid zone
Green months are your sowing window: March to September.
Growing notes
Annual phlox is a fast, cheerful filler that fits the cool-season desert garden in Mildura and Broken Hill. Because it hates transplanting, always sow direct and thin the seedlings rather than moving them; disturbed roots sulk and often fail to recover.
The most common failure here is sowing too late and losing the crop to heat. Phlox flowers well in mild conditions but scorches and stops once temperatures push past the mid-thirties, so aim for autumn and winter sowings that finish flowering before the worst of summer. A short spring sowing works too, provided you accept a briefer season.
Good drainage matters. In heavy or waterlogged soil the seedlings damp off, so lighten the bed with compost and coarse sand if it holds water. Water deeply but let the surface dry between soakings, as constant wet at the crown invites rot in the dry-heat climate. Deadhead spent flowers to stretch the display, and feed lightly once or twice through the season for stronger, longer flowering. Full sun gives the most compact, floriferous plants; in shade they stretch and flower thinly.
Phlox at a glance
| Sowing depth | 3 mm |
|---|---|
| Plant spacing | 10-15 cm |
| Row spacing | 20-30 cm |
| Germination | 10-20 days |
| Days to maturity | 70 days |
| Frost tolerance | Hardy |
| Method | Raise Seedlings,Sow Direct |
Common questions
- when to sow annual phlox in the desert
- Sow direct from March to September so plants grow through the cool months and flower before summer heat. This gives the longest, most reliable display in arid gardens.
- can you transplant phlox seedlings
- It is best not to. Annual phlox resents root disturbance, so sow it 3 mm deep where it is to flower and thin the seedlings rather than moving them.
- why did my phlox stop flowering
- Heat is the usual cause. Once temperatures climb past the mid-thirties phlox scorches and stalls, so grow it as a cool-season flower and sow early enough to finish before summer.
- how far apart should phlox be spaced
- Thin to 10-15 cm apart, with rows 20-30 cm. A dense stand supports itself and produces a solid sheet of colour rather than sparse, floppy stems.
Track phlox in your garden — sow dates, harvest countdowns, reminders. Free.
Add to my garden