Zone 5b Fall Garden Cleanup: What to Do Before the First Frost

Every fall I walk my gardens with a cup of coffee and a notebook, and every fall the list is longer than I remember. After more than 30 years of gardening on our river property in northern Illinois (Zone 5b), I’ve learned that a good fall garden cleanup isn’t about making everything neat and bare. It’s about doing the right tasks at the right time, so the garden comes back stronger in spring.

Taking a little time to focus on our gardens in the fall can yield significant rewards. This post walks you through what to do in the garden in fall: the 21 fall garden cleanup tasks that I do in my gardens, organized by timing: before the first frost, right after it, and before the ground freezes. There’s also a free printable Zone 5b Fall Garden Cleanup Checklist that you can access in my Resource Library.

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Quick Answer: When Should You Start Fall Garden Cleanup in Zone 5b?

In Zone 5b, the first frost usually arrives in early to mid-October, and the ground typically freezes sometime in late November or early December. That gives you three natural windows:

• September to early October (before the first frost): Divide, transplant, plant, collect seeds, and tag anything you plan to dig up later. Clean up the vegetable garden.
• Mid-October to early November (right after the first frost): Pull frost-killed annuals, dig tender tubers, finish any cleanup that still needs to be done. Cut down perennials that should be cleaned up in fall, and plant garlic and spring bulbs.
• November (before the ground freezes): Keep watering, mulch, put away hoses, and get your tools and shed ready for winter.

Check your own average frost date (your local extension office or the Farmers’ Almanac frost date tool will give you one by zip code), since even within Zone 5b it can vary by a couple of weeks. Here along the river, we often get frost a little earlier than the folks in town.

Don’t Clean Up Too Much

The biggest change in how I do fall cleanup over the years is that I leave a lot more standing. Hollow stems and seed heads shelter native bees and beneficial insects over the winter, and the birds love the seeds. There are some plants that I don’t cut back until spring as they add visual interest to your gardens during the winter. They also can provide food and shelter for insects and wildlife. Some of those include:

• Ornamental grasses
• Sedum
• Coneflowers
• Black-eyed Susans
• Hydrangeas

Wondering what to cut down and what to leave? I’ve put together a full plant-by-plant guide to which perennials to cut back in the fall, including the ones you should always leave for spring.

My Zone 5b Fall Garden Cleanup Checklist: 21 Tasks

You don’t have to do all 21 autumn garden tasks in one weekend (I certainly don’t). Work through this fall garden maintenance list in order as the weather turns, and use the printable checklist to keep track.

Part 1: Before the First Frost (Tasks 1 to 10)

1. Walk the Garden and Make a List
   • We should start by taking a close look at our garden. This means checking the soil quality, noting any weeds, and identifying plants that need attention. I jot down what did well, what struggled, and anything that needs to move. That list becomes next spring’s plan.
2. Keep Pulling Weeds
   • Weeds compete for nutrients and water. They also reseed, so don’t stop pulling the weeds, even as your garden is starting to die back. Every weed you pull before it sets seed this fall is hundreds you won’t be pulling next June.
3. Plant and Transplant While the Sales Are On
   • Hardy perennials, such as asters, sedums, and mums, can withstand cooler temperatures and bloom beautifully before winter sets in. At this time of year many trees, shrubs, and perennials are 50% off. If you plant in September or even early October in Illinois, it gives roots time to get established before the first frost. Here’s my full list of what to plant in your garden in the fall for a beautiful spring garden.
   • Cool-season vegetables like kale, spinach, radishes, and lettuce thrive in the fall. If it’s still September, there’s time to sow one more crop before winter. Radishes and spinach are very fast-growing.

Some of my favorite fall blooming plants

4. Divide Overgrown Perennials
   • Fall is an excellent time to divide perennials. This not only promotes a healthier plant, but it also allows you to add to your garden for free! We start by identifying clumps that have grown too large, are crowding other plants, or are telling you they need to be divided. Iris is one of those kinds of plants. When they need to be divided, they have a ring in the center where nothing is growing.
   • Using a spade, we carefully lift the clump and separate it into smaller sections. Each section should ideally contain roots and shoots. Replant these divisions immediately at the same depth they were previously growing. This process rejuvenates the existing plants and fills gaps in our garden. Remember to water well after replanting to encourage root establishment. In Zone 5b, try to finish dividing about four to six weeks before the ground freezes so the roots can get established.
5. Dig Out the Plants That Wandered
   • This is also a time when I dig out plants that have either spread or reseeded into areas where I don’t want them. I have black-eyed Susans that I didn’t plant in my yard, but a few years ago they started blooming. They have become a bit invasive, so I’m digging out the clumps that shouldn’t be where they are.
   • I also have common milkweed in my yard. I didn’t plant it, and I’ve been pulling it out for the last two years. Nothing has gone to seed this year that I’m aware of, so I’m hoping it stops coming back. Don’t worry; I still have monarch butterflies that live in my gardens. I have butterfly milkweed, which is very pretty and doesn’t take over the garden.

6. Collect Seeds
   • This is also the time of year when we are collecting seeds. I collect seeds from my snapdragons, sweet peas, and zinnias. I would like to learn how to collect impatiens seed, as I have trouble finding the kind of impatiens I love in seed form.
   • I let my seed heads dry on the plant, then store the seeds in labeled paper envelopes somewhere cool and dry.

7. Tag Your Dahlias and Tender Tubers
   • This is the time of year when you need to start thinking about digging up tubers. Before frost takes the foliage, I tag the bottom of each stalk so I know the varieties once everything turns brown and looks the same.
8. Aerate and Overseed the Lawn
   • Aeration is vital to promote a healthy lawn. We can improve air circulation and nutrient absorption by perforating the soil with holes. Ideally, we should aerate when the soil is moist but not overly wet.
   • After aerating, seeding our lawn is essential. We can select a seed mix appropriate for our climate. Spreading seeds evenly helps fill in bare spots and enhance overall lawn density. Using a broadcast spreader allows for precise seed distribution. Following up with light watering ensures seeds are established effectively. In northern Illinois, late August through mid-September is the sweet spot. If you’ve missed that window, wait until spring.
9. Refresh Your Porch Pots
   • We can breathe new life into our flower pots by selecting autumn-themed plants. One year I used a mix of mums, ornamental cabbage, chard, and dwarf pepper plants. You can also use pansies, asters, and kale. They all offer vibrant colors that resonate with the season. Don’t forget to change the potting soil, ensuring our plants have the nutrients they need as the weather cools. Keep deadheading the mums and pansies, and they’ll carry your porch right through to Thanksgiving. For more ideas, see my simple fall porch decor ideas.

10. Clean Up the Vegetable Garden
    • Pull spent tomato, squash, bean, pea, and cucumber plants. Toss any diseased vines rather than composting them.
    • Harvest carrots, beets, potatoes, and any other root plants that you might have in your garden.
    • Once my vegetable garden is cleaned up, I add a layer of compost, shredded leaves, or straw over the empty beds so the soil is ready for spring. Here are my tips for growing a successful vegetable garden if you’re already dreaming about next year.

Part 2: Right After the First Frost (Tasks 11 to 16)

11. Pull Frost-Killed Annuals and Diseased Foliage
    • Once the first frost hits, annuals like impatiens, zinnias, and marigolds turn to mush overnight. Pull them and add them to the compost. Anything with powdery mildew or other disease goes in the trash, not the compost pile, so it doesn’t come back next year. For perennials, I follow my fall perennial cutback guide and leave the rest standing for winter.

12. Dig and Store Dahlia Tubers
    • Dahlia tubers actually have to die back after a frost, and then they are ready to dig up. I wait about a week after frost blackens the foliage, cut the stalks down to a few inches, then lift the clumps with a garden fork, let them dry, and store them somewhere cool (40 to 50 °F) that won’t freeze. Digging up tubers and storing them will be a whole post of its own.
13. Plant Garlic
    • I also plant my garlic in my vegetable garden in the fall. In Zone 5b, mid-October to early November is ideal, once the daytime temperatures are in the mid-50s (roughly two to four weeks after the first frost). Plant cloves pointy end up, about 2 inches deep and 6 inches apart, then cover with straw.
14. Plant Spring Bulbs
    • For vibrant spring blooms, fall planting is essential. You should consider bulbs like tulips, daffodils, hyacinths, crocuses, alliums, and muscari, which need to be planted before the ground freezes. In Zone 5b, that’s usually mid-October through mid-November once the soil has cooled.
      • Choose a sunny spot with well-drained soil.
      • Plant bulbs at the appropriate depth, usually three times the height of the bulb.
      • Space bulbs adequately to allow for growth.
      • Water them in well, then add a layer of mulch to regulate soil temperature and retain moisture.
      • I cover the bulbs with blood meal to keep the squirrels from digging them up.
    • If deer are a problem in your area, I would stay away from tulips and crocus, as the deer start to eat them from the minute they poke their heads through the soil.

15. Prune Shrubs (Only the Right Ones)
    • Pruning shrubs in the fall helps maintain their shape and encourages healthy growth. We want to start by using clean, sharp tools to avoid damaging the plants.
      • Assess the Plant: Look for dead, damaged, or diseased branches.
      • Remove Deadwood: Cut back to healthy wood, ensuring cuts are at a 45-degree angle.
      • Thin Out: Open up the center of dense shrubs and branches that are crossing each other for better air circulation.
    • It’s also crucial not to over-prune; we should aim to remove no more than one-third of the plant at a time. And hold off on spring bloomers like lilacs, forsythia, and bigleaf hydrangeas. They’ve already set next year’s buds, so a fall trim cuts off your spring flowers.
16. Mow and Bag the Leaves for Mulch
    • Dealing with fallen leaves can feel overwhelming, but there are efficient ways to manage them. We use our lawn mower with the bagger attached. The leaves from the bag are what we use to mulch our perennial garden. Shredded leaves break down faster than whole ones, won’t mat down and smother your plants, and they are FREE.
    • Regardless of the method, you should aim to clear leaves off the lawn regularly. Leaving them on the lawn can block sunlight and smother grass. A rake or leaf blower works too if you don’t have a bagger.
    • Leaf removal for us starts in late August and doesn’t seem to end. We are still cleaning up leaves the next spring.

Part 3: Before the Ground Freezes (Tasks 17 to 21)

17. Keep Watering Until the Ground Freezes
    • A tendency to stop watering in the fall is not good for your gardens. Even as the plants are dying back, they still need to be watered for healthy root systems to withstand the winter. This matters most for anything planted this year and for evergreens, which lose moisture all winter.
      • Monitor Soil Moisture: Before watering, check the soil’s moisture level. If it’s still damp, wait a few days.
      • Timing: Water early in the day to minimize evaporation. This allows plants to absorb moisture before evening temperatures drop.
      • Deep Watering: Instead of frequent light watering, we should strive for deep watering less often. This encourages root growth and resilience.

18. Mulch Your Beds
    • When we lay down mulch, it acts as an insulating layer for our garden beds. We should use materials like shredded leaves, straw, or pine needles, as these help maintain soil temperature and moisture levels. If you’re deciding what to buy, here’s how I weigh bagged or bulk mulch.
      • Clean the Area: Remove any debris or dead plants from the garden.
      • Layer Thickness: Aim for a thickness of 2 to 4 inches. This helps prevent weeds while maintaining moisture.
      • Keep Away from Stems: Ensure the mulch is placed a few inches away from plant stems to avoid rot.
    • For anything you have planted or divided this fall, add an extra layer after the ground freezes. It keeps the soil frozen, which prevents the freeze and thaw cycles that heave new plants right out of the ground.

19. Drain and Store Hoses (and Empty Your Pots)
    • Before the first hard freeze, disconnect and drain hoses, shut off outdoor spigots from inside if you can, and empty rain barrels. Bring in clay and terracotta pots or turn them upside down, because water trapped inside will crack them over a Zone 5b winter.
20. Clean, Sharpen, and Store Your Tools
    • Before storing our tools, we need to clean them thoroughly. A mix of soap and water can do wonders for removing dirt and residue. For metal tools, we should dry them completely to prevent rust.
    • Next, you should sharpen blades on pruners and hoes. This step ensures that they’re ready for use next season. Applying a light coat of oil to prevent rust on metal parts is also beneficial. This is also a great time to get the blade on your lawnmower sharpened. Our local hardware store and lawn mower repair shop both offer this service.
    • Once cleaned and sharpened, we can store tools in a dry, accessible location. Hanging them on hooks keeps them off the floor and helps keep them in good condition.
21. Organize the Outdoor Storage Areas (Garage, Shed, Greenhouse)
    • The fall is also a great time to organize your outdoor storage areas. Remove any unused items and expired products like fertilizers and pesticides. It’s essential to safely dispose of the materials according to local guidelines.
    • Categorize your tools and supplies. Consider using shelves, hooks, and bins to organize items. Labeling containers and shelves helps us find everything quickly in the future. Try grouping similar items together. For example, keep watering cans, pots, and soil in the same space.
    • This is also a good time to take inventory of what needs to be replaced. Every year we lose a few things to either breakage or accidental discard, so I make a list to purchase in early spring or put them on my holiday gift list 🙂

Essential Fall Garden Cleanup Tools

To complete your fall garden tasks effectively, having the right tools on hand is essential. These are the ones I reach for every fall:

• Rake: A sturdy rake is vital for clearing leaves and debris. My favorite rake is a telescoping rake, as I can get into narrow and large areas with the same rake.
• Hand Tools: Tools like trowels and pruners will be important for any planting or pruning we plan to do.
• Spade and Garden Fork: For dividing perennials and lifting dahlia tubers.
• Watering Can or Hose: You’ll need a watering can or hose to provide adequate moisture, especially if rain is sparse.
• Lawn Mower with a Bagger: Our secret to FREE leaf mulch.
• Wheelbarrow and Gloves: For hauling and for saving your hands.

Making sure your tools are working and clean will help you work efficiently and effectively, making your fall gardening tasks more enjoyable and productive.

After the Work: Make Your Outdoor Space Cozy for Fall

Once the chores are done, I love to enjoy the garden for a few more weeks. Transforming our patios and porches into cozy retreats for fall can be easy. We can add comfortable seating paired with plaid blankets for warmth, string lights or lanterns for a warm glow, and pumpkins tucked around the space. Grasses, cattails, and fall weeds from the side of the road all make beautiful outdoor floral arrangements.

We enjoy using hay bales in our outdoor living space as additional seating in the fall months. It’s not only functional, it adds a bit of whimsy to your space. You can find more of my fall decorating ideas here.

Get Your Free Zone 5b Fall Garden Cleanup Checklist

Do you want all 21 tasks on one page? Grab my FREE printable Zone 5b Fall Garden Cleanup Checklist, organized by timing so you know exactly what to do before the first frost, right after it, and before the ground freezes. It’s the perfect partner to my 23 Simple Spring Garden Cleanup Tips (+ Free Checklist).

Final Thoughts

It seems like just yesterday I was getting ready to plant my new seedlings and get the gardens started, and here we are, another fall! A little work now means a garden that wakes up healthy and ready in the spring. Truth be told, I’m ready for the cooler weather and heading indoors to enjoy my cozy fall home.

Peace and Love,

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