How to Start Perennials in the Fall

Perennials return year after year, bringing color and structure to the garden.

Perennial flowers return each year bringing color and structure to the garden. Unlike annuals that must be reseeded each year, perennials will die back in the fall. In the spring new growth emerges from the hardy root systems. Perennials tend to live at least three years, but most live longer. Perennials are ideal for creating structure in the garden and can pair nicely with annual flowers and vegetables. Plant perennials in early fall so that the roots will have time to get established before the winter frosts arrive.

Things You'll Need

• Shovel
• Garden fork or rototiller
• Compost or manure
• Mulch

Instructions

1. Prepare the planting bed in late summer or early fall. Most perennials enjoy full sun to part shade, though many can grow in deep shade. Ask at your local nursery when purchasing plants to determine the sun requirements.

2. Dig a hole 10 inches deep and fill it with water. If there is still water in the hole in 10 hours, the site does not provide adequate drainage for perennials. Select a new site or consider building a raised bed.

3. Remove all weeds, weed roots, rocks, sticks and other materials from the garden bed. Spread a 2- to 4-foot layer of organic matter over the planting area. Use well-seasoned manure or compost. Work the material into the top 10 to 12 inches of soil using a rototiller or a garden fork.

4. Determine where each perennial will go. Consider sun requirements and bloom time. Mixing early- and late-blooming perennials together will give your garden season-long color and interest. Spacing varies depending on the variety, so ask at your garden center when you purchase plants.

5. Dig planting holes at each planting site. Make the holes slightly wider and as deep as the nursery pots each plant came in. Slide the root ball out of the nursery pot, being careful not to disturb the root ball. Cut thin plastic pots away if you do not care about saving the pot.

6. Place the root ball of the perennial into the hole, making sure it is the same depth in the soil as it was in the nursery pot. Fill in or remove soil from under the root ball until the plant can rest at the right depth in the hole. Fill in around the root ball and press the soil down firmly with the flat of your hand.

7. Soak the area around each perennial within four to six hours of planting. In most areas wet fall weather will make watering unnecessary. To determine when to water, stick your finger into the top 1 inch of soil; when it feels dry to the touch, soak each plant to a depth of 6 inches.

8. Spread a 2- to 4-inch layer of mulch around each plant to regulate soil temperatures and moisture through the fall. When winter frosts kill off the foliage, cut the perennials back to the ground and cover each plant with a 4-inch layer of mulch.

Tips & Warnings

• Perennial flowers are most commonly planted in the spring, but fall planting is also suitable. Dividing perennial roots and bulbs is almost always performed in the fall.

• In frost-free climates, perennials will grow year-round without the annual die back found in areas that get heavy frost and snow.

References

• Purdue University Department of Horticulture and Landscape Architecture: Growing Perennial Flowers
• Clemson University Cooperative Extension: Growing Perennials
• University of Vermont Extension: Growing Perennials

Resources

• Sunset: The Perfect Raised Bed