Phlox

Use our zone-based planting guide to know when to plant phlox.

Plant name Zone Start seeds indoors (spring/fall) Start seeds outdoors (spring/fall) Plant seedlings/transplants outdoors (spring/fall) Plant spacing # plants per person
Phlox 3a March 1-15 April 15-May 1 On/around May 15 (after last frost) 6-36 inches (depending on variety) n/a
Phlox 3b March 1-15 April 15-May 1 On/around May 15 (after last frost) 6-36 inches (depending on variety) n/a
Phlox 4a March 1-15 April 15-May 1 On/around May 15 (after last frost) 6-36 inches (depending on variety) n/a
Phlox 4b March 1-15 April 15-May 1 On/around May 15 (after last frost) 6-36 inches (depending on variety) n/a
Phlox 5a Feb. 1-15 March 15-April 1 On/around April 15 (after last frost) 6-36 inches (depending on variety) n/a
Phlox 5b Feb. 1-15 March 15-April 1 On/around April 15 (after last frost) 6-36 inches (depending on variety) n/a
Phlox 6a Feb. 1-15 March 15-April 1 On/around April 15 (after last frost) 6-36 inches (depending on variety) n/a
Phlox 6b Feb. 1-15 March 15-April 1 On/around April 15 (after last frost) 6-36 inches (depending on variety) n/a
Phlox 7a Feb. 1-15 March 15-April 1 On/around April 15 (after last frost) 6-36 inches (depending on variety) n/a
Phlox 7b Feb. 1-15 March 15-April 1 On/around April 15 (after last frost) 6-36 inches (depending on variety) n/a
Phlox 8a Jan. 1-15 Feb. 15-March 1 On/around March 15 (after last frost) 6-36 inches (depending on variety) n/a
Phlox 8b Jan. 1-15 Feb. 15-March 1 On/around March 15 (after last frost) 6-36 inches (depending on variety) n/a
Phlox 9a Not recommended Not recommended Not recommended Not recommended n/a
Phlox 9b Not recommended Not recommended Not recommended Not recommended n/a
Phlox 10a Not recommended Not recommended Not recommended Not recommended n/a
Phlox 10b Not recommended Not recommended Not recommended Not recommended n/a
Phlox 11a Not recommended Not recommended Not recommended Not recommended n/a
Phlox 11b Not recommended Not recommended Not recommended Not recommended n/a

* There are a huge number of varieties available. Consult your Extension office for one that will work well for your area. Start seeds indoors 8-10 weeks before your average last frost date, or direct sow as soon as soil can be worked in the spring. Plant seedlings or transplants after the threat of frost has passed.