Did you know that fall is the best time to plant most perennials in warm climates? In fall, the ground is warm and the air is cool, giving plants a perfect opportunity to work on their roots. Plants that have this “extra season” to establish are bigger, beautiful, and ready to perform in spring.
Perennials in fall:
- Need less additional water
- Face less competition from weeds
- Are less susceptible to pest issues
How to plant in fall:
They are a couple key differences when planting this time of year. First is that you should not fertilize plants in fall. Doing so can encourage them to put on new growth late in the year instead of going dormant, which will only cause the plant to suffer in a frost. If you’d like to provide a little nutrition to your new plants, it’s safe to mix in a small amount of compost when planting. Compost has a very low nutrient content compared to fertilizers (think an NPK value of 1:1:1 instead of 10:10:10).
Your new perennials will need to be watered well when they’re put in the ground, even if you’ve got rain in the forecast. When planting, it is best to water both before and after the hole is completely backfilled. This way, you can ensure that the plant's entire root ball is saturated.
We generally recommend planting perennials at least 5-6 weeks before your first frost date. Exceptionally cold-hardy perennials are less of a concern, but all plants benefit from an opportunity to establish before winter!
Temperature isn’t the only factor that plays into a plant successfully overwintering. Location can have an impact. Plants in exposed areas (like the middle of the yard) are more vulnerable than plants in protected areas (like the south side of a building). Plants in containers tend to freeze far more easily than those in the ground, so containers can be sheltered in an unheated garage or outbuilding during cold weather.
Be on the lookout for poorly draining soil this fall and winter! This is referred to as “winter wet soil” and is a common killer for Coneflowers, Blanket Flowers, Sedums, etc. Poorly draining soil can be improved with the addition of compost, sand, or fine gravel at the time of planting.