Warm Season Grasses
Warm season grasses tend to have more spectacular blooms, but they also bloom late in the season. If you have a short growing season they may only be just starting to bloom when a hard frost hits. Miscanthus is finished once that happens. The blooms that have opened will remain, but the leaves turn beige and no more blooms are produced.
Here is a list of warm season grasses:
- Andropogon - Big bluestem
- Bouteloua - Blue gama
- Imperata - Japanese blood grass
- Miscanthus - Maiden grass
- Panicum - Switch grass
- Pennisetum - Fountain grass
- Saccharum - Hardy pampas grass
- Schizachyrium - Little bluestem
- Sorghastrum - Indian grass
- Sporobolus - Prairie dropseed and Alkali sacaton
So the use of warm season grasses means that part of your garden will look very bare well into the spring. If you have a lot of garden space planted in warm season grasses, your garden will not show any greenery before late May or maybe even well into June. In a climate with a short growing season you may feel a little cheated. Pennisetum is especially suspenseful because it is the very last to grow, waiting until well into May or even June in a Zones 4 or 5.
Cool Season Grasses
The cool season grasses are much better suited to cold climate gardens. They are in a hurry to produce offspring, so they are up and growing and blooming as quickly as they can. They like the cool weather. So they bloom early, meaning that frost won't ruin the blossoms. Many have blossoms that hang around until winter.
Here is a list of cool season grasses:
- Achnatherum - Spear grass
- Alopecurus - Golden foxtail grass
- Arrhenatherum - Bulbous oat grass
- Calamagrostis - Feather reed grass
- Carex - technically not a grass, and many are evergreen
- Chasmanthium - Northern sea oats
- Deschampsia - Tufted hair grass
- Elymus - Wheat grass or Wild rye
- Festuca - Fescue
- Helictotrichon - Blue oat grass
- Juncus - technically not a grass, and may be evergreen
- Koeleria - Hair grass
- Luzula - technically not a grass, and will probably be evergreen
- Molinia - Moor grass
- Phalaris - Ribbon grass
- Poa - Blue meadow grass
- Sesleria - Moor grass
- Stipa - Feather grass (S. brachytricha, an exception, blooms in lt Aug or Sept)
The four champion/pretty-well-fool-proof grasses in the cool season category are:
- Calamagrostis, particularly Karl Foerster, our top-selling grass
- Deschampsia - very hardy and Goldtau is absolutely lovely
- Festuca - many to choose from
- Helictotrichon - its evergreen in most climates, so that's a real bonus!
On our website we state the blooming time for a grass. The earlier blooming warm season grasses are the ones to choose in a cool climate. For instance Panicum blooms early and is hardy, so it is a good choice.
Of course we understand a gardener's love of pushing the boundaries, so these are only suggestions. Even I do it. In my Zone 5 garden with early sunset of 5pm, I have a Pampas grass that I have nursed back from near death (because I transplanted it at the wrong time!). Last year it started to look happy, but didn't bloom. Maybe, just maybe it will this year....?