Should You Prune in Spring or Fall?

When done correctly, pruning promotes plant health, supports growth, and enhances your garden’s appearance. At Delk Management, we provide expert landscaping and lawn care services for commercial and residential clients across the region.

Our spring vs fall pruning guide shares best practices for pruning in Spokane’s Zone 6a climate to help you maintain a thriving landscape. Here’s how to prune your plants effectively this season.

Should You Prune in Spring or Fall?

Fall pruning can benefit certain plants by removing dead or damaged growth and preparing them for winter dormancy. In Eastern Washington and Northern Idaho, where Spokane’s Zone 6a climate brings cold winters with potential frost by late October, pruning must be timed carefully to avoid stressing plants. Late September to mid-October is ideal, before the first expected frost. Pruning too late can stimulate new growth that won’t harden before winter, increasing frost damage risk. For many plants, spring pruning is safer, as it allows cuts to heal during active growth.

Spring vs. Fall Pruning: Which Is Best for Your Plants?

Deciding whether to prune in spring or fall depends on the plant type, your goals, and Spokane’s Zone 6a climate. Here’s a breakdown to help you choose the right season for pruning in Eastern Washington and Northern Idaho:

• Fall Pruning (Late September to Mid-October):
  • Best For: Perennials (e.g., peonies, hostas), ornamental grasses, and select shrubs that bloom on new wood (e.g., butterfly bush). Light pruning of deciduous trees to remove dead or damaged branches is also safe.
  • Benefits: Removes spent foliage, reduces disease risk (e.g., powdery mildew on peonies), and tidies the garden before winter.
  • Risks in Zone 6a: Pruning after mid-October can stimulate new growth that won’t harden before winter, leading to frost damage. Avoid pruning spring-blooming shrubs like lilacs or roses, as it removes next year’s flower buds or exposes cuts to frost.
  • When to Choose Fall: Opt for fall pruning for cleanup tasks or to shape plants that tolerate it, but stop by mid-October to avoid winter stress.
• Spring Pruning (Late March to Early April):
  • Best For: Spring-blooming shrubs (e.g., lilacs, azaleas, new wood hydrangeas), roses, evergreens, and most deciduous trees. Prune lilacs after blooming (May-June) and roses when buds swell in spring.
  • Benefits: Spring pruning allows cuts to heal during active growth, reducing disease risk and frost damage. It’s ideal for shaping plants and encouraging blooms on old wood (e.g., lilacs) or new wood (e.g., roses).
  • Risks in Zone 6a: Pruning too early (before late March) may expose plants to late frosts. Avoid heavy pruning of newly planted trees or shrubs to prevent stress.
  • When to Choose Spring: Choose spring for most flowering shrubs, roses, and trees to maximize blooms and plant health, especially in Spokane’s cold climate.
• Zone 6a Considerations: Spokane’s cold winters and early frosts make spring pruning safer for many plants, as it avoids winter injury. For fall pruning, stick to hardy perennials or grasses and monitor frost dates. Always check the plant’s bloom cycle (old wood vs. new wood) before pruning.

Not sure which season is best for your plants? Our team at Delk Management can assess your landscape and provide tailored pruning advice for the Northwest’s unique climate.

Which Plants to Prune in Fall

Not all plants benefit from fall pruning in Zone 6a. Focus on these for best results:

• Perennials: Plants like peonies and hostas can be cut back to 2-3 inches above ground to remove spent foliage and reduce disease risk. Avoid heavy pruning of marginally hardy perennials like lavender, which may not survive winters if cut back too far.
• Ornamental Grasses: Cut back to 6-8 inches to maintain tidiness and prevent rot. Examples include miscanthus and fountain grass.
• Deciduous Trees: Light pruning to remove dead or damaged branches is safe, but avoid heavy cuts to prevent winter stress. Maples and birches should only receive minimal trimming.

Avoid Pruning in Fall:

• Roses: In Zone 6a, fall pruning of roses risks frost damage to new cuts. Instead, prune in early spring (late March to early April) when buds swell, removing dead canes and shaping for healthy blooms. In fall, only remove diseased or broken canes and mound soil or mulch around the base for winter protection.
• Lilacs: Fall pruning of lilacs removes next season’s flower buds, which form on old wood in summer. Prune lilacs immediately after blooming (late spring, May-June) to maintain blooms and shape. In fall, only remove dead or damaged branches.
• Evergreens, Hydrangeas, Azaleas: These are best pruned in spring or early summer to avoid winter injury or loss of blooms.

Need help? Our landscape maintenance services can ensure proper care for your outdoor space.

Following Pruning Techniques

Using proper pruning techniques protects plant health. Follow these steps for spring and fall pruning:

• Assess the Plant: Identify dead, damaged, or crossing branches. For flowering shrubs, confirm they bloom on new wood (e.g., butterfly bush) before pruning.
• Use Sharp Tools: Tools include bypass pruners, loppers, and a pruning saw for thicker branches.
• Make Clean Cuts: Cut at a 45-degree angle just above a bud or node to promote healing and reduce disease.
• Don’t Over-Prune: Remove no more than one-quarter of the plant to avoid stress in Zone 6a’s cold winters.

These pruning tips for gardeners work for select shrubs, perennials, and light tree pruning. For complex tasks like pruning trees in fall, contact our expert team.

Fall Pruning Mistakes to Avoid

Improper pruning can harm plants. Avoid these common pruning mistakes if you are located in Zone 6a:

• Pruning Too Late: Pruning after mid-October risks frost damage to fresh cuts. Check local frost dates before pruning.
• Pruning Spring-Blooming Shrubs: Avoid fall pruning of lilacs, azaleas, or hydrangeas, as it removes next year’s flower buds.
• Over-Pruning: Heavy cuts, especially on trees or shrubs, can weaken plants before winter.
• Using Dull Tools: Blunt tools cause jagged cuts, increasing disease risk.

Our team at Delk Management can help you avoid these errors with professional landscaping and maintenance.

Tools Needed for Fall Pruning

Having the right tools needed for fall pruning makes the job easier and safer. Invest in:

• Bypass Pruners: For small branches and perennials like peonies.
• Loppers: For thicker branches on shrubs like butterfly bush.
• Pruning Saw: For larger branches on deciduous trees.
• Gloves and Safety Glasses: To protect against debris.

Keep tools clean and sharp to ensure precise cuts and healthy plants.

FAQs About Fall Pruning

Why is fall pruning beneficial for some plants?

For certain plants like peonies and ornamental grasses, fall pruning removes dead growth and reduces disease risk, preparing them for winter.

Which plants should be pruned in fall in Zone 6a?

Perennials (e.g., peonies, hostas), ornamental grasses, and some shrubs (e.g., butterfly bush). Avoid roses, lilacs, hydrangeas, and azaleas.

What are the steps for proper fall pruning?
Assess the plant, use sharp tools, make clean 45-degree cuts, and remove no more than one-quarter of the plant.

How does fall pruning benefit plant health?
It removes dead material and reduces disease but must be timed before frost to avoid stress.

Are there risks to fall pruning in Spokane?
Yes, pruning after mid-October or cutting spring-blooming shrubs can lead to frost damage or loss of blooms.

What tools are recommended for fall pruning?
Bypass pruners, loppers, a pruning saw, and protective gear are recommended tools for pruning.

Can I prune flowering plants in fall?
Only shrubs that bloom on new wood (e.g., butterfly bush). Avoid spring-bloomers like lilacs, roses, or hydrangeas.

Prune with Confidence with Delk Management

Ready to tackle fall pruning for perennials and select shrubs? Delk Management is here to help Eastern Washington and Northern Idaho residents and businesses maintain stunning landscapes. Our experts follow Zone 6a-specific best practices to ensure your plants thrive.Contact us today to schedule a consultation and explore our full range of services!