What NOT to Plant in Fall Gardens
Early fall can be a good time to plant perennials in many places in the intermountain West. (Perennials are your flowers that return year after year.)
But as I’ve learned the hard way in my Colorado garden…
There are some flowers you may not want to plant in the fall in Colorado, Wyoming and similar western states.
Some plants need a little more time for their roots to get established before winter.
Here are a few examples.
Avoid planting “marginally hardy perennials” in the fall.
What’s a marginally hardy perennial?
It’s a plant that won’t come back if it gets too cold or if it can’t handle winter conditions where you live.
Usually, these plants are better off when they’re planted in the late spring or early summer. That way, their roots have ALL summer to get established in the ground.
This gives them a better chance of surviving their first winter.
Here’s a simple trick to tell if a perennial is marginally cold hardy >>
The pink flower pictured above is known as Gaura or Wandflower (Gaura lindheimeri). I LOVE this flower plant, but it’s marginally hardy in my garden along the Front Range of Colorado.
Some years it comes back. Some years it doesn’t, and I have to replace it.
Because I know it’s marginally hardy in my garden, I wait until spring to plant it. I don’t plant it in the fall. That way, it has as much time as possible to get established before winter.
Native western salvias often do better with spring planting.
Native western salvias occur naturally in Texas, New Mexico and the Southwest. They go by botanical names like Salvia greggii and Salvia darcyi.
You may see popular ones at the garden center called Furman’s Red Sage and Wild Thing Sage.
Native western salvias thrive in hot and dry climates, so they grow well in our summers at our lower elevations.
These showy flowers are drought tolerant, long blooming and a favorite among hummingbirds.
So many reasons to love them!
But native salvias can be fickle in our winters.
It’s best to plant them in the spring or early summer (like May or June), rather than in the fall.
That way, their roots can get a running head start into autumn and winter.
In general, don’t plant evergreen trees in the fall. Spring is a better time.
While we’re on the subject of “what not to plant in the fall” in states like Colorado and Wyoming, add evergreen trees to your list too.
Evergreens (aka, “conifers”) are your trees that have needles. They don’t go dormant in the winter. This means they don’t go into hibernation mode like your trees that lose their leaves. They are awake and “ever green” through the winter.
Evergreen trees need to be well watered over the winter.
They’re also vulnerable to our tough winter conditions — like our drying winter winds and our big temperature swings — because they aren’t dormant.
It’s best to plant your evergreen trees in the spring, so their roots have more time to get established before winter.
Keep in mind, these are guidelines, rather than rules.
We may get a mild winter, and your plant babies may be fine.
But if you’d rather not risk it, then just wait until late spring to plant the flowers and trees in this article.
Related tips that may interest you:
- “How can you tell if a perennial is marginally hardy?”
- 3 plants that struggle in western winters (what NOT to plant in your Colorado landscape)
- “What plant hardiness zone is Colorado?”
