Lets prepare for the plant sale

Fall is an ideal time to divide spring- and summer-blooming perennials. Dividing them now gives the roots time to settle over the winter so they are well-established and ready to pot up or sell by next spring's garden club sale.

The Lake Forest Park list of top perennials to divide in fall.

• Hostas (Hosta): Separate crowded tuber or root clumps using a sharp spade or knife, ensuring each section has healthy roots and multiple growth points. Ensure fibrous-rooted plants (like Hostas and Daylilies) have their crowns sitting exactly at the soil line.
• Daylilies (Hemerocallis): Dig up large clumps with a shovel, trim the foliage back to 3 to 4 inches, and pull or cut the sections apart.
• Bearded Irises & Siberian Irises (Iris): Lift and divide rhizomes or fibrous roots, trim the leaves down to 4 to 6 inches, and replant with the top of the rhizomes just at the soil line. Plant all rhizomes (like Bearded Irises) right at the surface
• Peonies (Paeonia): Cut back old stems and divide the root clumps carefully, making sure each division has 3 to 5 eyes. Plant them shallowly with the eyes just 1 to 2 inches below the surface.
• Tall Garden Phlox (Phlox paniculata): Cut back the old foliage and pull or split the loosened root clumps into sections with several strong shoots. This should happen often as they bloom better when they are in "fresh" soil.
• Coneflowers (Echinacea) & Black-Eyed Susans (Rudbeckia): Dig up the entire root ball every few years and split it into vigorous, smaller chunks with plenty of active roots.
• Shasta Daisies (Leucanthemum x superbum): Divide every 2 to 3 years by lifting the outer, healthier portions of the clump and discarding the woody center. These are not a great seller but are a very overlooked perennial.
• Bleeding Hearts (Dicentra): Divide the brittle root clumps after the foliage has died back, making sure each piece has a few visible growth eyes. We have a lot of wild dicentra in LFP but the hybrid varieties sell well.
• Coral Bells (Heuchera): Separate woody or crowded crowns and trim back leggy leaves before potting or replanting. There are so many new hybrids of Heuchera lately.
• Hardy Geraniums (Cranesbills): Lift the shallow root systems and gently pull or cut them apart into smaller rooted sections.

Tips for Preparing Sale Plants Now

• Potting vs. Ground Replanting: If you are prepping for a spring plant sale, you can either plant the divisions directly into garden beds to grow out over winter and dig/pot them up in early spring, or pot them up immediately into nursery containers using a good potting mix and store them safely.
• Timing: Try to complete fall dividing at least 4 to 6 weeks before our first hard freeze so the roots can anchor. Lake Forest Parks first frost usually falls between Nov 11th to Nov 20th however hard freezes are very rare.
• What to Skip: Avoid dividing fall-blooming perennials (like chrysanthemums and asters), woody-based plants like Lavender, or shrubs like Hydrangeas and Roses, which do not split via shovel division.

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For the best success at our spring plant sale, potting your divisions in the fall is highly recommended over digging them up in the spring. Fall-potted plants develop a robust, established root system over the winter, making them look lush, professional, and healthy to buyers by spring.

Here is how to successfully pot and overwinter your garden club divisions in the Pacific Northwest:

 

1. Potting Logistics

• Pot Selection: Use standard 1-gallon or 4-inch nursery pots with excellent drainage holes. Clean used pots with a 10% bleach solution to prevent spreading diseases.

• Soil Mix: Do not use garden soil, which packs tight and suffocates roots in containers. Use a high-quality, well-draining potting mix amended with perlite or composted bark to ensure winter rains don't rot the roots.

• Planting Depth: see above.

• Label Immediately: Use waterproof markers on plastic plant stakes. Write the common name, cultivar/color (if known), and basic care (e.g., "Hosta - Part Shade"). Wind and rain will wash away sharpie on wet pots, so push the stakes deep.

 

2. Winter Care & Protection

While these perennials are hardy in the ground, their roots are much more vulnerable to freezing temperatures when elevated in plastic pots.

• The "Heeling-In" Method: Group your potted divisions tightly together in a protected part of your yard (such as against a north- or east-facing house wall). Pack mulch, sawdust, leaves, or wood chips entirely around the pots up to their rims. This insulates the pots and mimics being in the ground.

• Moisture Management: The standard Seattle winter rain will usually provide all the moisture they need. However, keep them out from under deep house eaves where they might dry out completely. If a rare, extended dry freeze is forecasted, check that the soil inside the pots is slightly damp beforehand, as dry roots freeze faster than moist ones.

• Air Circulation: Avoid sealing the plants tightly under solid plastic tarps, which traps heat on sunny days, encourages premature sprouting, and creates a breeding ground for mold and rot.

 

3. Spring Prep for the Sale

• Clean-Up: In late winter or early spring (around March), pull the pots out of the mulch. Trim off any mushy, dead winter foliage to expose the fresh green crowns.

• Weed Control: Top off the pots with a fresh layer of potting mix or compost if the soil settled over winter, and pull out any opportunistic winter weeds like shotweed.

• Top Dressing: If you want premium pricing, add a thin layer of fine bark mulch to the top of each pot right before the sale to give it a pristine, retail-ready look. ​​