Garden Phlox
Phlox paniculata
Plant out around your last spring frost. Space plants 18 in (46 cm) apart.
Photo: Didier Descouens, CC BY-SA 4.0 · source
When to plant
Timed from your frost dates, so it holds wherever you garden. Give yours and every step below becomes a date.
Optimal Transplant (Nursery Plant or Division)
From a plantRecommended from a plant- Plant outaround your last spring frost
- First harvestsummer-fall, once established
Optimal Dormant Fall Direct Sow
From seedRecommended from seed- Sow outdoors2 weeks after your first fall frost
- First harvestsummer-fall, once established
Growing garden phlox
- Spacing in the row
- 18 in (46 cm)
- Between rows
- 24 in (61 cm)
- Planting depth
- Set nursery plants at the depth they grew in the pot.
- Sun
- Full Sun to Part Shade
- Soil
- Rich, moist, organic, well-drained soil; tolerates clay. Wide pH range.
- Germination
- 21-30 (after 60-90 days cold stratification)
- Harvest season
- Summer-Fall
- Mature height
- 2-4 feet
- Support
- Stake tall cultivars; heavy flower heads can flop.
- Hardy to
- USDA zone 4
- Life cycle
- Perennial
Plant nursery plants or divisions in spring. Seed needs 60-90 days cold stratification - sow outdoors in late fall.
Watering. Not drought tolerant - water in dry spells and mulch to keep roots cool, but water at the base: overhead watering spreads powdery mildew.
Feeding
- Growing
- Top-dress with compost in spring; prefers moderately fertile to rich soil.
- How often
- Once a year, in early spring. A compost top-dressing or light balanced feed as growth emerges is enough; a second light feed after the first flush fades can bring more bloom.
- Note
- Thin crowded stems in spring and cut plants down and clear debris in fall to reduce powdery mildew. Shearing by a third in mid-spring gives shorter, bushier plants with slightly later bloom.
Your garden phlox, planned to the day.
Canopy turns these timings into dates from your own frost data, places every plant at its spacing on your garden map, and tracks it all the way to harvest.