September Gardening Tips for Colorado

September Gardening Tips for Colorado

September is an ideal time to add perennials to your landscape, by spring your new plants will be established and ready to thrive.

Make a list of desired renovations and begin planning for next year. I keep a gardening journal and take notes during the summer on what plants bloomed well and areas where I need to add or subtract plants.

Trees and Shrubs

To encourage dormancy and improve winter survival, begin limiting water.
Remove snow from all branches if there’s an early snowstorm.

Flowers, Ground Cover, Perennials, and Ornamental Grasses

Continue watering, weeding, and deadheading, as needed.
Divide early season perennials like Siberian Iris, Day Lilies, and Peonies to help ensure plants are well established and require less water during cooler months.
Remove plants that have died.
Plant spring bulbs like Daffodils, Tulips, Hyacinths, and Crocus.
Add fall and winter color with pansies and violas.


After a thorough watering or soaking rain, core-aerate your lawn.
Bring new life to your lawn by over-seeding or sodding thin areas.
Lay down a good fertilizer to give nourishment during the winter months