Q&A: Lawn Conversation into Perennial Border

Q&A: Perennial Planting

Question: Lawn Conversion into Perennial Border

I am planning on converting a part of my lawn into a perennial border.  I will be smothering the grass this year and plan to plant the perennials in autumn.  Is it okay to start perennial seeds in May to be planted in the ground in September?  I was planning on using tufted hair grass, echinacea, lupines and veronicastrum.

Any advice would be much appreciated.


Our Q&A team members (Debbie, Lisa, Derek and Kiyoko) all congratulate you for your choice for making a difference for biodiversity.

With the exception of the lupines, there should be no issue in starting the plants you mention from seed now so that you may plant them later in the season. You would need to carefully “baby them” in their first weeks to help them become strong. Once they reach a good size, “potting them up” by planting them into larger containers will lessen the vigilant watering required to carry new plants in small containers through the summer.

Some plants require cold stratification. Others require scarification, the scratching of the surface of the seed. Cold stratification requires your seed be exposed to a cold or cold-and-wet treatment for six to 12 weeks. This is very important to most native plants. All your native seed selections need light to germinate, so press the seed into the dampened soil and cover the container with a clear lid and place into a fridge for the cold treatment. This treatment applies to Echinacea angustifolia, E. pallida (E. purpurea seeds don’t need cold stratification, but most native seed germination is improved by a period of cold or cold and wet), tufted hair grass and Veronicastrum. The seeds then can be either kept in a warm bright space indoors until they germinate and grow into little seedlings and then planted outside, or the container can be placed directly outdoors where the seeds will germinate once the temperatures start rising. This is a link on the stratification and planting process:

Lupines require scarification or soaking in water for 24-48 hours to improve germination. Scarification is a process by which you begin to break down the very tough seed coat mechanically, scratching the seed on a concrete floor or with a metal file. Soaking the seeds in water has a similar effect. Lupines can be sown directly into the soil in autumn (or in spring as soon as the soil becomes workable). The recommendation is not to start the plants early if they will be planted into the garden only in fall as lupines do not like to be transplanted once they have developed their long taproot.

Your plant selection is great from an ecological perspective and will look wonderful, too. Having a native grass in the mix is very helpful, along with Echinacea angustifolia and Veronicastrum virginicum. A suggestion to consider: why not add another native plant or nativar (cultivar of a native plant) like meadow blazing star, dotted blazing star, giant hyssop, or blue vervain to your plant list instead of the non-native lupine?

You are applauded for undertaking to grow some wonderful native plants.