Ask Annie- September Garden Checklist

We are now into September, where the garden can feel like it's on borrowed time. The heat softens, light turns golden, and the garden gets its final wind. This is Second Summer, and here is your September garden checklist: 

Zone 4a: Cooler nights arrive; frost is possible late in the month

Zone 4b: Ideal growing conditions return; watch long-range forecasts

Zone 5a: Warm days continue; excellent conditions for Fall planting

• Fall planting begins: trees, shrubs, and perennials thrive now
• Divide Summer-blooming perennials if needed
• Transplant during cooler evenings to reduce stress 

• Refresh mulch to protect soil as temperatures fluctuate
• Begin adding compost to empty or tired beds
• Lightly loosen compacted soil before Fall planting
• Leave healthy roots in place when cleaning up spent plants 

• Continue deep watering; roots are still growing
• Adjust irrigation as nights cool and evaporation slows
• Avoid high-nitrogen fertilizers; encourage root strength instead
• Water new Fall plantings consistently 

• Cut back plants that are finished blooming or diseased
• Leave sturdy stems for structure, interest, and wildlife habitat
• Remove supports from plants that are naturally standing strong 

• Don’t let weeds seed; this is next year’s problem in disguise
• Watch for late-season pests lingering in warm weather
• Clean up fallen debris that could harbor disease
• Improve airflow as humidity drops 

• Keep late bloomers intact as pollinators rely on them!
• Leave seed heads for birds and overwintering insects
• Maintain water sources during hot stretches

• Soak in the last bit of lingering warmth
• Take notes on what deserves repeating next year
• Photograph textures, seed heads, and fading blooms
• Enjoy Second Summer: the garden’s quiet encore 

And remember, gardening is never about perfection, it’s about curiosity, patience, and perserverance! I’m cheering you on as you try new things, learn from the missteps, and celebrate each little success. Until our next chat, happy gardening and keep growing!

-Annie

Have a perennial issue, mystery, or design dilemma? Annie can help!

Always approachable and happy to help!