Planning and Planting perennials in Fall

Cassey Anderson, Master Gardener Coordinator in Adams County 

This is a great time of the year to get a few new perennials in the garden. As a bonus many nurseries are having great sales at the moment! 

I have been adding new garden bed space and reducing the lawn in my yard. This past spring I mulched with about 6” of arborists chips to prep this bed area (a silver lining to having had to remove many ash trees due to Emerald Ash Borer). This fall I decided that it’s ready to start filling it in. I purchased a Kniphofia flamenco (Red Hot Poker) and a Baptisia australis (False Indigo).

I started by determining where I wanted the plants. When planning locations for your perennials you want to consider the amount of sun that they need and will receive, how you will water them (no plant is xeric in its first year of establishment), and how exposed or protected the area is. In this area I've got drip lines running to each plant although I may run a secondary drip line with in-line emitters as I get more plants in the bed. Each of these plants takes full sun with glee and thankfully that is in abundance in this area! 

Perennials establish best if you bare-root them. This means removing the potting media they were grown in. One of the easiest ways to bare-root your perennials is by soaking the plant in a bucket of water and gently teasing the soil out of the roots. Root washing helps ensure good soil to root contact and plants are more likely to establish quickly than if you leave them in the “cushy” media.

This Kniphofia is nicely rooted and not pot-bound. 

The Baptisia is a little pot-bound but root washing
can rectify this for herbaceous perennials

One of the big differences you find when you bare-root your perennials is that the roots will get very long, so you may need to arrange your holes differently. You can tease the roots out to fill the space in the hole most effectively. That said, if your soil is in good condition you may not need to dig as big of a hole once you wash all the media off your roots.

Look at those gorgeous roots making an appearance!

The roots on the Baptisia were SO long, 
I had to go get a shovel and dig a larger
hole to accommodate them. 

The next step is to dig your holes, loosen the sides of the holes if you have any smooth surfaces from your shovel. There is not need to amend with any organic material unless you plan to amend the whole garden bed. Gently place your plants in the hole and distribute the roots evenly. Cover the roots up while holding the plant up (this takes some more care than with plants that have not been bare-rooted). 

Getting the plant in place, tease the 
roots so they can spread out and 
establish in the soil. 

Start to fill in gently around the
roots with your native soil. 

Finally, you want to water your plants in well over the next couple of days. The warm soils of autumn ensure that you can get some good root growth before the cold of winter really sets in. A layer of mulch will retain moisture for longer and has the benefit of reducing weeds in the area.

It might not look like much right now but I'm hopeful that by next year it will be looking much more filled in.