Blue Glow vs Blue Flame vs Blue Ember Agave
The short answer
All three are blue-green agaves that do best in the Valley with shade from the hot afternoon sun. Blue Glow stays one small rosette with red and yellow edges and rarely makes pups. Blue Flame is bigger and pups into a wide clump. Blue Ember sits in between, with red edges and red tips.
Side by side
| Blue Glow | Blue Flame | Blue Ember | |
|---|---|---|---|
| Rosette size | About 2 ft tall, 2 to 3 ft wide | About 3 ft tall, 3 to 4 ft wide | About 2 to 3 ft tall, 3 to 4 ft wide |
| Pups | Rarely; stays one rosette | Lots; the clump can spread 6 to 10 ft | Makes side rosettes that carry on after the mother plant blooms |
| Leaves | Blue-green with red and yellow edges that glow in back light | Waxy blue-green, curving inward | Smooth blue-green with red, toothed edges and red tips |
| Growth | Slow | Slow | Moderate |
| Water once rooted | About every 2 weeks in summer | About every 2 weeks in summer | About every 2 to 3 weeks in summer |
| Sun | Morning sun, shade from hot afternoon sun | Mostly sun, shade from hot afternoon sun | Full sun with some shade in the hottest part of the day |
| Cold hardy | About 15°F | About 20 to 25°F | About 20 to 25°F |
| Spines | Softer leaves, short sharp red tip | Fine teeth, sharp tip that curves inward | Toothed edges, sharp red tip |
| Best use | Pots, entries, courtyards | Beds and rock gardens with room to clump | Patios, borders, rock gardens and pots |
Plants in a 30 inch box or larger come on a bigger truck. Large specimen curbside delivery is one flat fee by ZIP, $50 to $75 in the Valley, and it replaces the regular delivery fee. Large specimens are curbside delivery only. Plan on having your landscaper or installer move it into place.
Choose Blue Glow if...
- You want one tidy rosette that never needs dividing.
- The spot gets back light, so the red and yellow edges glow.
- Your yard runs colder. It is the hardiest of the three, to about 15°F.
Choose Blue Flame if...
- You want a bigger agave that fills a bed over time.
- You like having pups to replant or give away.
- You have room for a clump, or you are willing to pull pups each year.
Choose Blue Ember if...
- You want red edges and red tips on a compact, even rosette.
- You want a pot or border agave a little wider than Blue Glow.
Questions people ask
What is the difference between Blue Glow and Blue Flame?
Both are crosses with foxtail agave as a parent. Blue Glow stays a single, smaller rosette with red and yellow edges. Blue Flame gets about 3 feet tall and pups into a wide clump.
Do these agaves need afternoon shade in Phoenix?
Yes, all three do best with shade from the hot western sun on summer afternoons. Keep them off hot west walls and reflected heat, where the leaves can yellow and burn.
Which one is best for a pot?
Blue Glow, since it stays small and rarely pups. Blue Ember also suits pots. Blue Flame works in a large pot if you pull the pups.
Do they die after they bloom?
Yes. Each rosette blooms once, often after 10 to 15 years, and then dies. Blue Flame and Blue Ember leave pups behind, while Blue Glow usually needs replacing.
How cold can they take?
Blue Glow handles about 15°F, and Blue Flame and Blue Ember about 20 to 25°F. On hard freeze nights, cover them with frost cloth that reaches the ground and remove it in the morning.
Are they safe around pets?
Agave is mildly poisonous if chewed. The sap can irritate a pet's mouth and skin, and the sharp leaf tips can poke, so snip the tips near walks.