What Can I Plant in August Before My First Frost?

Think you've missed your chance to plant a garden this year?

You're not alone. By August, many gardeners assume the growing season is winding down and start pulling plants instead of planting new ones.

But here's the surprise:

For many parts of the country, August is actually one of the best times to start a fall garden.

Whether you've just harvested garlic, cleared out spent bean plants, or have an empty raised bed waiting for something new, there's still plenty of time to grow a delicious harvest before your first frost.

The key isn't where you live—it's knowing how many growing days you have left.

In this guide, I'll show you exactly how to figure out what you can still plant in August and which vegetables, herbs, and flowers have plenty of time to thrive before cold weather arrives.

Why Your First Frost Date Matters More Than Your Growing Zone

One of the biggest misconceptions in gardening is that your USDA Hardiness Zone tells you when to plant vegetables.

It doesn't.

Hardiness zones tell you which perennial plants can survive winter temperatures. When it comes to annual vegetables, your average first frost date is far more important.

Think of your first frost date as your gardening deadline.

If carrots take about 70 days to mature and your average first frost is still 90 days away, you have plenty of time.

If frost is only 40 days away, you'll want to choose faster-growing crops instead.

Learning this one simple concept will make planning your fall garden much easier every year.

Before You Grab Your Seed Packets...

 Not sure when your first frost is? Check your average first frost date with the Old Farmer's Almanac, then come back here to see what you can still plant.

👉 Check Your Average First Frost Date Here

What Can You Plant Before Your First Frost?

Instead of worrying about states or regions, simply figure out how many growing days you have left before your average first frost.

Then choose crops that mature within that timeframe.

If You Have 90+ Days Before Frost

You still have enough time to grow many warm-season vegetables.

Good choices include:

• Bush beans

• Cucumbers (fast-maturing varieties)

• Summer squash

• Potatoes

• Mini pumpkins

• Winter squash (quick varieties)

• Sweet corn (early varieties)

Toward the end of August, you can also begin sowing cool-season crops for an extended harvest.

If You Have 60–90 Days Before Frost

This is the sweet spot for planting a productive fall garden.

Excellent choices include:

• Carrots

• Beets

• Turnips

• Broccoli

• Cabbage

• Kale

• Swiss chard

• Kohlrabi

• Bok choy

• Chinese cabbage

Many of these vegetables actually develop sweeter flavor after experiencing a light frost.

If You Have Less Than 60 Days Before Frost

Don't give up on gardening just yet.

Many fast-growing vegetables can still provide a wonderful harvest.

Plant:

• Radishes

• Leaf lettuce

• Spinach

• Arugula

• Mustard greens

• Baby kale

• Green onions

• Asian greens

Many of these crops can be harvested multiple times using the cut-and-come-again method.

Don't Forget Herbs!

Herbs often appreciate the cooler temperatures that arrive toward the end of summer.

Consider planting:

• Cilantro

• Dill

• Parsley

• Chives

• Chervil

If you already grow perennial herbs like thyme, oregano, or sage, August is also a great time to tidy them up and prepare them for fall.

Flowers You Can Still Plant in August

August isn't just for vegetables.

Depending on your climate, you can also plant flowers that brighten your fall garden or establish themselves for next spring.

Good choices include:

• Calendula

• Nasturtiums

• Sweet Alyssum

• Pansies

• Snapdragons (transplants)

• Bachelor's Buttons (warmer climates)

Many of these flowers continue attracting pollinators long after summer begins fading.

Tips for Success When Planting in August

Late summer gardening comes with a few unique challenges.

Water Consistently

August heat dries soil much faster than spring weather. Keep newly planted seeds evenly moist until seedlings become established.

Mulch Your Beds

Adding straw, shredded leaves, or untreated grass clippings helps keep the soil cooler while reducing moisture loss.

Give Seedlings Afternoon Shade

If temperatures are still extremely hot where you live, consider providing temporary shade during the hottest part of the day.

Refresh Your Soil

After removing summer crops, add compost before planting again. Fresh nutrients will give your fall vegetables a healthy start.

Common Mistakes When Planting in August

Even experienced gardeners make these mistakes.

• Waiting too long to plant.

• Forgetting to check the "days to maturity" on seed packets.

• Underwatering during hot weather.

• Planting warm-season vegetables that won't mature before frost.

• Forgetting to mulch.

Avoid these simple mistakes and you'll greatly improve your chances of a successful fall harvest.

Frequently Asked Questions

Is August too late to start a garden?

Not at all. In many parts of the country, August is the perfect time to begin a productive fall garden.

What vegetables grow the fastest before frost?

Radishes, lettuce, spinach, arugula, mustard greens, and green onions are among the quickest crops to mature.

Should I plant seeds or transplants?

Both work well. Fast-growing greens are easy to sow directly, while broccoli, cabbage, and cauliflower often perform better as transplants.

Can vegetables survive a light frost?

Yes. Many cool-season vegetables—including kale, spinach, carrots, and Brussels sprouts—actually become sweeter after a light frost.

One Last Thought

One of my favorite things about gardening is that nature constantly reminds us it's never too late to grow something new.

Every season offers another opportunity.

If you still have warm days ahead before your first frost, don't let those empty garden beds sit unused.

Plant a few seeds.

Try something you've never grown before.

You might discover that your favorite harvest of the year comes after summer is over.

Happy planting!

— Theresa

Plan Ahead

✔️ Check your average first frost date.

✔️ Read the "days to maturity" on every seed packet.

✔️ Refresh harvested beds with compost.

✔️ Try one new cool-season crop this year.

✔️ Bookmark this guide so you can return every August.

🌿What's In This Guide

I'll be honest...

This wasn't part of some carefully planned garden design.

It started as the place where I dumped everything I didn't know what to do with.

Grass clippings.

Half-finished compost.

Old leaves.

Aged horse manure I got for free from a single horse owner on Craigslist.

Garden trimmings.

Cardboard from our recent move cross country from Texas to now Vermont.

Even poor heavy clay soil that seemed too lifeless to grow much of anything.

What looked like a messy pile slowly transformed into one of the healthiest tomato beds I've ever grown.

It wasn't luck.

It was biology.

Looking back, I accidentally created exactly the kind of environment nature uses to build healthy soil on a forest floor. I just didn't realize it at the time. 

Without realizing it at the time, I had built a variation of what's commonly known as lasagna gardening, a simple no-dig gardening technique that lets nature build rich, living soil from the ground up.

If you've been struggling with poor soil, expensive raised beds, or worn-out gardens, this Dump Garden Bed method may completely change how you think about growing food.

By the end of the season, this messy little experiment produced one of the healthiest tomato harvests I'd ever grown!

What Is a Dump Garden Bed?

I jokingly call mine a Dump Garden Bed because that's exactly how it started.

Instead of hauling away organic waste, I layered it directly where I wanted to grow vegetables.

Although I gave it my own nickname, the idea shares principles with:

• No-Dig Gardening

• Lasagna Gardening

• Sheet Composting

• Hugelkultur (to a lesser extent)

The goal is simple:

Build healthy soil by feeding the organisms that create it.

I’ve always loved the concept of no-dig gardening, especially when I have lived for years in areas with hard clay soil. I thought when I moved to VT that I would hit the black gold soil jackpot. 

Nope, I could start my own pottery business strictly from my yard soil.

This garden bed method is THE BEST and cheapest way to work with what you have. The idea of building raised beds and then having spend hundreds on making pretty little raised beds was just absolutely ridiculous.

For me, gardening has always been about growing more while spending less. If I'm investing hundreds of dollars into lumber, imported soil, and expensive raised beds before I even plant a tomato, I'm missing one of the biggest benefits of gardening. 

You negate most of that advantage by spending an arm and a leg just getting the beds ready.

So I worked with what I had on hand, and that is the entire concept of my no-dig dump garden bed. 

Use whatever trimmings, manure, compost, poor soil, YOU HAVE, and make it work for you in layers. That poor soil as it breaks down with the green scraps, will turn into over time a crumbly masterpiece.

Everything I Layered

• Cardboard

• Grass clippings (both dry and green)

• Garden trimmings

• Leaves

• Half-finished plus fresh compost

• Aged horse manure

• Native clay soil

This is by no means a strict recipe for your garden, this is just what I had available to me to use. 

If you are concerned about how to secure manure there are almost always people giving it away for free on craigslist. 

Search your community and surrounding areas. I drove at first for over an hour and just put a tarp in the back of my car to haul some home and did multiple trips from a lady who owned a single, yet highly productive, horse. 

Why Lasagna Gardening Works

When people first see a dump garden bed, it can look like nothing more than a pile of yard waste and compost. But underneath the surface, something remarkable is happening.

Every layer of organic matter—whether it's leaves, grass clippings, cardboard, compost, or aged manure—becomes food for billions of beneficial microorganisms living in the soil. These bacteria and fungi begin breaking everything down, turning what was once waste into nutrients your plants can actually use.

As this process continues, earthworms and other beneficial soil creatures move in, tunneling through the layers and naturally mixing everything together. Their activity improves airflow, creates channels for water to penetrate the soil, and leaves behind nutrient-rich castings that help feed your plants.

Over time, all of this biological activity transforms poor, compacted soil into loose, dark, living soil that's full of life.

One of the biggest benefits I noticed was moisture retention. Because the bed contained so much organic material, it held onto water much longer than my traditional garden beds. During the heat of summer, that meant less frequent watering and healthier, less-stressed tomato plants.

As the materials continue to decompose, they also release nutrients gradually instead of all at once. Rather than depending on frequent fertilizer applications, the bed becomes a slow, steady source of nutrition that supports healthy root development throughout the growing season.

In many ways, this is exactly how nature builds fertile soil on a forest floor. Year after year, fallen leaves and plant debris decompose, feeding the underground ecosystem and creating rich, healthy earth. A no-dig garden simply works with that natural process instead of fighting against it.

By focusing on soil biology rather than constantly feeding the plant itself, you're creating a healthier ecosystem where tomatoes—and many other vegetables—can develop stronger root systems, better drought tolerance, and long-term productivity.

🌱 Before You Begin...

You don't need perfect ingredients to build a successful dump garden bed. One of the biggest lessons I learned is that nature isn't looking for perfection—it's looking for diversity. 

Use what you have, work with your local materials, and let the soil biology do the rest. 

🌱Compare and Contrast Garden Beds

Lay down cardboard. Soak with the garden hose to aid the breakdown process

Step 2

Add any rough organic material. This can be twigs, pulled yard/garden weeds that you have on hand. I sometimes use stinging nettle since I remove it for my pets and kids anyways. A great soil addition! So in other words, bulky organic material of some kind.

Step 3

Add whatever soil you have in your area. Dig it up from the edge of your yard, or an older garden bed you don’t use, wherever you see fit to use some soil.

Step 4

Add your manure, this can be fresh or aged. See my article here all about sources of manure and what stage they need to be in to use!

Step 5

Add anything you can from your compost pile. Mine was partially broken down, I sifted out the really rotten items to keep decomposing in my pile, and took any of the broken down goodies to use in my bed. Eggshells and coffee grounds, by the way, are amazing for your tomato plants. Want tips on composting? Click here!

Step 6

Add green fresh grass clippings. This will create great heat to break down your bottom layers.

Step 7

Add more poor soil from your yard.

Step 8 

Add dry organic material. You can spread your fresh grass clippings out in the sun to dry them to add this layer or if you have leftover dry leaves to add as a layer. 

Step 9 

Repeat with whatever you have available, fresh cow manure, or more compost material.

Step 10

Add top layer of whatever soil you have on hand or if you actually have some composted soil, this would be the best one. But if you are like me, and have limited options, I put a layer of clay soil on top a few inches mixed with more compost and horse manure.

Step 11

Plant your tomato transplants directly into this. You can do this right away after you build the bed, or if you are doing this bed in early spring, let it sit for a month or 2 to break down and then put your tomato transplants in after all danger of frost is gone!

Step 12

Water deeply to get all the way to the bottom layer.

Think of each layer as another ingredient in a recipe. You don't need every single one, but the more diverse your organic materials are, the richer your finished soil will become. 

I repeat THERE ARE NO RULES!! Only ask yourself this for your layers, is it clean and organic? Can it break down over time? If you answered yes to this, then by all means, start layering a mix of organic items to make your best soil of all time! The only real rule is the larger items that take the longest to break down (twigs, etc.) should always be on the bottom layer! Keep your new bed evenly moist to fuel the breakdown process and you are well on your way to a glorious production of tomatoes. 

The Results

I'll admit...

Even I wasn't expecting this much growth.

By midsummer, the tomato plants had exploded with healthy green foliage.

The soil underneath had transformed from heavy clay into something dark, crumbly, and full of earthworms.

Instead of drying out every afternoon, the bed stayed moist for days after watering.

By harvest time...

       

🎥 Want to see the entire transformation? Click here to watch the full video on Instagram. 

🌿 Rustic Tip

If you have neighbors who rake leaves every fall, ask if you can take them. They'll usually be thrilled that someone wants them, and your future garden will thank you.

Pro Tip: Be sure to continuously push up the soil at the base of tomato plants to expand their root systems.

What I'd Do Differently

I was really greatly surprised by how well this did in its first season. I had started really late, but it still gave me a TON of healthy tomatoes. 

I think the only thing I would do differently this year is to keep building up more and more layers, even after the plants are grown. 

It’s always good to push up soil in a mound around the base of your tomato plants, those create additional root systems to further nourish your plant. 

What I would do would be to mound it further up around the base and keep the layering going all season long to create continuous feeding.

Mistakes to Avoid

❌ Too much fresh manure not aged properly that burn plants

❌ Using glossy cardboard and not removing packaging tape

❌ Not watering enough

❌ Layering everything too thick

Common Questions 

Can I plant immediately? I recommend already having tomato transplants with at least their true leaves sprouted, ready to go in. This will ensure greater success than trying to start from seed in this bed.

Can I use fresh grass clippings? Yes! And I did this in layers; it helps the overall bed to stay warm and break down. 

Does it smell? It does not have an odor, as most of your composted items are partly broken down and the manure is aged. 

Will it attract rodents? No, make sure your compost is purely veggie scraps and do not include any meat in there. I had zero rodent issues.

Can I use kitchen scraps? Yes! Absolutely, the more the merrier!

Can I build one over grass? I built all of my no-dig beds, including the dump garden bed over grass. The cardboard that you put as your bottom layer kills off the grass growth, preserves the natural microbial layer of the topsoil, and creates a very healthy garden for your crop.

Does this work in clay soil? Yes! I have only had clay soil, and it works really well. I even used mixed thin layers of clay soil in my dump garden bed.

How long does it last? This garden bed will last you the life of your property. Each season I would add more layers to it, feeding it to keep the soil diversity healthy and your team of microorganisms and earthworms well fed.

Final Thoughts

When I first started building this bed, I wasn't trying to invent a new gardening method.

I was simply trying to grow food with the materials I already had.

Looking back, that's exactly why it worked.

Nature doesn't care whether your garden is expensive.

It doesn't care if your raised beds are perfectly square.

Healthy soil is built one layer at a time.

Feed the soil, and the soil will feed your garden.

And if this little "Dump Garden Bed" taught me anything, it's that sometimes the messiest ideas grow into the biggest harvests.

🌱 I'd Love to Hear From You

Have you ever tried lasagna gardening or built your own version of a dump garden bed?

What materials did you use?

Did you discover something that worked surprisingly well?

Share your experience in the comments. Some of my favorite gardening tips have come from conversations with other gardeners.