15 Worst Gardening Mistakes and How to Avoid Them in 2022

I’ve had this idea for a blog post for months. I wanted to share some of my worst mistakes as a gardener to help you avoid them in your own garden bed. I’ve found that no matter how many years I’ve been gardening, there’s always more to learn and there are always new problems to overcome.

This year I’ve added cruciferous vegetables to my gardens like broccoli, cauliflower, and Brussels sprouts. I’ve been watching over them with some anxiety as the little green worms decimated my leaves and took up residence inside my vegetables.

Next year, should I decide to plant these types again, I will be trying other methods to keep the pests away. My garden is largely organic (meaning I don’t prefer to use pesticides) so some pests are to be expected, but there’s certainly a point at which too much is too much.

All of that to say: As a gardener, I’m ALWAYS learning. I think part of being a gardener is also being humble enough to listen to new advice or new ideas. Last year I had a woefully disappointing tomato crop, while in the same weather conditions my friend had more tomatoes than she knew what to do with. I learned some really helpful ideas from her, and this year my tomatoes already look more promising.

If you’re interested in more help with gardening, we also have a guide teaching you how to start a vegetable garden in 9 steps!

OK so enough setting the stage, on to some of the worst gardening mistakes you can make, and what you can do instead.

Disclosure: As an Amazon Associate we earn from qualifying purchases. 

Gardening Mistake #1: Not Understanding Your Soil

If you’re planting your garden for the first time in a new area, it’s essential that you understand your soil. There are different types of soil that may affect your garden. There are also things to consider like pH levels, nitrogen, potassium, and phosphorous.

Types of Soil

Your soil will be different from mine because there are so many things that makeup soil. One of those differences will be consistency. While there are many types of soil, there are four main types that you may experience at your house. It may also be a combination of these types.

• Sandy Soil. Sandy soil is acidic and is often low in nutrients, but it is light and drains easily.
• Clay Soil. Clay soil is very dense and doesn’t drain well at all. It can be difficult to cultivate this type of soil because it’s heavy and doesn’t turn over easily. One benefit of clay soil is it tends to be high in nutrients.
• Silty Soil. Silty soil is good for a garden. It’s not as nutrient-rich as clay soil, but it does hold moisture and has a higher nutrient content than sandy soil.
• Loamy Soil. Loamy soil is often considered the best type of soil for gardening. It’s a good mix of sand, silt, and clay making it high in nutrients and able to retain moisture. Compared to clay-only soil it’s also easy to cultivate.

The pH Level and Nutrients in Your Soil

Another thing to consider about your soil is the pH level and the nutrients in the soil. You can get a soil test kit online, at a local gardening store, or you may be able to get one from your local extension office. A soil test kid will allow you to understand the makeup of your soil. To learn how to use a home soil test kit, check out our guide.

You can test for the pH level (how acidic it is) only, or you can also test phosphorus, nitrogen, and potassium.

What are pH levels? 

The pH level of your soil ranges from acidic to alkaline. This range is measured in numbers from 1-14 and is referred to as the pH. Soil that is lower than 7 is considered acidic and anything above 7 is considered alkaline.

Depending on what you’re growing, you may want your soil to be more alkaline or more acidic. For instance, blueberries do well in acidic soil, lavender prefers alkaline soil. Most plants grow best in a neutral range of about 6.2 to 7.0.

What are other important nutrients in your soil?

• Nitrogen may be the most important nutrient found in soil. It helps give plants their healthy green color and energy to grow and produce fruit.
• Potassium is considered the second most important nutrient. This nutrient helps with photosynthesis and other physiological processes of plants.
• Phosphorus helps plants grow roots, seeds, fruits, and flowers. Phosphorus also contributes to a plant’s ability to fight disease.

Gardening Mistake #2: Not Providing Your Garden With Good Nutrients

Once you understand the makeup of your soil, you can assess what you might need to add to your garden soil. If the nutrients are too low, you can add organic materials to raise the nutrient levels. Some of the ways you can do this are:

• Compost. We keep a compost pile in our yard and we throw things in it like fruit and veggie scraps, coffee grounds, and other non-meat leftovers. We also include wood ash, wood chips, and leaves to boost our compost.
• Manure. Manure can be another fantastic way to add nutrients to your soil. It does take some research to know what works best for your garden. For example, chicken manure is high in nitrogen but you should compost it a long time before adding it to your garden because the high nitrogen can burn or kill your plants. We often add chicken manure to our compost, mix it in, and let it sit before we introduce it into our garden.
• Vermicompost. Vermicompost means using earthworms to create natural fertilizer in your garden. You can add worms right to your soil or to a compost bin to create fertilized soil that can later be added to your garden.
• Mulch. Adding hay or straw to your garden to make a deep mulch can help retain moisture and add nutrients to the soil.
• Fertilizer. If you’re planning on starting a totally organic garden you may not be interested in using chemical fertilizers. A lot of people There are a LOT of different thoughts about it and people are all over the map. However, if you’ve tested your soil and you’ve discovered that it’s low in phosphorus, potassium, or nitrogen, many people choose to add bagged fertilizer to help. You can also purchase organic fertilizer which is a good alternative to synthetic fertilizer.

How to Get Your pH Balanced

If your soil is too alkaline or too acidic your plants will have a difficult time growing.  After using the pH soil test kit to see where your soil is, you can do some things to raise or lower your pH level.

If you find that your soil is too alkaline, you can add ground or powdered limestone to lower the pH number (remember, the lower the number the more acidic it is). For those of you with acidic soil, you can add sulfur, ferrous sulfate, or aluminum sulfate to make it more alkaline.

Gardening Mistake #3: Planting Seeds Instead of Seedlings

The picture above shows examples of seeds and bulbs that you can sow directly into your garden and expect to reap produce during the growing season. Things like lettuce, spinach, snow peas, and onion sets are things you can plant in early spring even in places that expect frost until May (like where we live in Pennsylvania).

When we planted our first garden in 2009, we went to the store and bought a bunch of seeds and planted those seeds directly in the ground. We waited until May to plant, but we didn’t realize we didn’t give these plants enough time to mature. Many plants such as tomatoes and peppers will be killed during a frost, which is why you can’t sow these seeds in the soil in March. If you wait until May, you may not get any produce at all or you’ll greatly restrict the harvest you would grow had you started sooner.

What’s the solution? You have a few options.

1. Start seeds indoors using flats and growing lights (or a window with good lighting). 
2. Grow seedlings in a greenhouse if you have access to one or have bought or built one of your own.
3. Grow plants in milk jug greenhouses, such as the one described by Trudi Davidoff of Wintersown.org 
4. Purchase seedlings from local greenhouses after danger of frost. 

Gardening Mistake #4: Planting Too Soon (Or Too Late)

This goes along with the topic above. For every plant you’re growing it will have a specific time to plant. This will be different depending on where you live as some places have longer growing seasons than others.

For a quick reference, here is a list of things you can plant in early spring when you’re still expecting frost:

• Lettuce (seeds)
• Spinach (seeds)
• Parsley (seeds)
• Onions (onion sets)
• Carrots (seeds)
• Peas (seeds)
• Kale (seeds) 
• Radishes (seeds) 
• Broccoli (plants)
• Turnips (seeds)

Things you can plant after danger of frost in late spring or early summer:

• Tomatoes (transplants)
• Peppers (transplants) 
• Cauliflower (transplants)
• Strawberries (transplants)
• Beans (seeds)
• Beets (seeds)
• Cabbage (transplant or seeds)
• Corn (seeds)
• Cucumbers (transplants or seeds)
• Summer Squash (transplants or seeds)
• Melons (transplants or seeds)
• Eggplants (transplanted)
• Pumpkins (seeds)
• Cilantro (seeds)
• Potatoes (seed potatoes) 
• Raspberries (transplants)

Things you can plant in the fall:

• Blueberries (transplants)
• Flowers (flower bulbs)
• Garlic (garlic bulbs)
• Asparagus (this takes several years to mature and needs to be winterized)
• Lettuce (seeds)
• Spinach (seeds)
• Carrots (seeds)

Keep in mind this list is primarily for those who live in a similar growing zone to us. If you live in a more tropical or warm area, your growing season will look different.

Gardening Mistake #5: Choosing Plants that Can’t Grow in Your Zone

Speaking of growing zones…You can’t grow every plant you want to in every part of the world. Sadly. If we could, I’d have an orange tree in my backyard because once I had the privilege of going to California and eating an orange right from a tree. It was delicious, and it was memorable, but I can’t grow one in Pennsylvania.

So for your garden, it’s essential that you know what you can actually grow in your zone. In the United States, the USDA created a growing zone map that shows plant hardiness and it’s split into 13 zones. You can type in your zip code to see what your growing zone is, and you can match that to the seeds or plants that you order.

For example, we live in zone 6 which means the minimum temperature we experience in a 30-year average is between -5 and -10 degrees Fahrenheit. Any perennials you plant will have to be able to survive the winter, and any annual you plant will have to have enough time to mature bloom, or produce fruit. Annuals that aren’t winter hardy will also have to be planted after the danger of frost (which is usually the end of May in Pennsylvania).

If you’re picking up seedlings from your local gardening store, you probably won’t be finding very many plants that you can’t grow in your garden. Plus, they can give you some good advice about what would be the best plants to grow in your area.

There are also some plants that might be perennials in warmer climates, but they won’t survive cold winters. I learned this when I planted rosemary in my garden thinking it would return the following year. Yes, rosemary can come back year after year and develop into a giant plant. Just not outside in Pennsylvania.

Gardening Mistake #6: Improperly Spacing Plants

I’ve done it before, and I’ll probably do it again, but one of the biggest gardening mistakes I make is not giving my plants enough room to grow. When you put in your little baby tomato plants it doesn’t look like they could really be a bother, but I currently have a tomato jungle in my garden that would negate that kind of thinking.

Most seeds or seedlings bought at the garden store will tell you how far apart you need to space the plants. Don’t ignore this information as I have in the past. You will regret it later, and you won’t be very happy when your plants are overcrowding each other and you have to either watch them grow poorly or rip out the plants you put so much hard work into.

In a small garden, it’s especially important that you think about how big a plant is going to get and space appropriately. You can’t plant a row of zucchini or pumpkins and NOT expect them to start taking over a small garden space.

Gardening Mistake #7: Planting Plants Where They Can’t Thrive

Each plant has a different need. Some need sun, some need shade, some need more water while others need less. Pay careful attention to where you plant your plants. Your sun-friendly plants might grow in the shade but they’re unlikely to produce a lot. Same with your shade-loving plants. They aren’t going to do as well if they’re placed in direct sunlight.

Some plants also shouldn’t be planted near other plants. A big one to remember is that tomato plants shouldn’t be growing next to black walnut trees. Walnut trees produce something called juglone which is toxic to tomato plants.

Gardening Mistake #8: Forgetting to Mark Off or Label Your Plants

This is another common mistake I make. I plant my seeds. I put in my seedlings. And I fail to label anything. I don’t know why I expect my memory to be so good when time and time again I’ve proven to myself what a lousy memory I have. I only remember doctor’s appointments when I write them on the calendar and they call me to remind me the day before.

There are quite a few garden labels to choose from on Amazon, or you can make your own if you’re feeling the DIY itch.

Gardening Mistake #9: Failing to Plant Diversity

A garden does better when you grow a diverse offering. Your diverse garden can attract pollinators and other beneficial bugs and insects more easily than one with only one type of plant. A garden with a variety of plants can also help repel unwanted pests. Basil is supposed to repel flies and mosquitos, and lavender is thought to keep away moths as well. Alliums are believed to repel a myriad of harmful pests like slugs, cabbage worms, and aphids.

Another good reason to plant different types of plants is that you can extend the time when you’re getting food from your yard. Strawberries are the first type of berry that ripens at our house, followed by raspberries, then blueberries, and finally blackberries. This keeps the berries comin’ and comin’ during the summer and we love it.

Gardening Mistake #10: Ignoring Planting Depth

This is another one of those “pay attention to the label” situations. Some plants need to be planted shallowly while others need to be planted more deeply. Roses need to be planted deeply, while lettuce seeds should be barely covered.

Another thing to pay attention to is how hard or difficult the soil is. Plants need to grow deep roots in order to survive. Sometimes gardeners will plant a seedling or seed in the soil without thinking about the plant breaking through the hard ground beneath. You can fix this by tilling up the soil or breaking it up by hand deeper than your plant or seeds.

Gardening Mistake #11: Planting Invasive Plants in Your Garden

It’s happened to the best of gardeners. They plant something directly in their flower bed, herb garden, or vegetable garden, and are excited to see it really taking off. Little do they know that it’s so prolific that it actually begins to take over the garden. Not only that, but it’s a perennial so you’ll be fighting off the plant for years if it gets out of control.

Often you’ll hear of “invasive” plants as those that are non-native but spread rapidly and aggressively. In this instance, it could be a native plant or it could be a non-native. The connecting factor is that it spreads aggressively and will overtake your landscape or gardens.

Here are some examples of plants that will grow aggressively and will be difficult to remove once they take hold:

1. Bamboo
2. Soapwort
3. Japanese honeysuckle
4. Balsam plants
5. Lemon balm
6. Mint
7. Catnip
8. Oregano
9. Bee balm
10. Lily-of-the-valley

Last year I started an herb garden and was pleased by how well the oregano was growing. This year I noticed that the oregano was kind of sort of TAKING OVER my herb garden. I was not aware that oregano grows shoots under the ground and spreads rapidly through the garden. I decided to pull the healthy plant out (yes, it was kind of sad) and replace it with a potted oregano plant instead. Unless you need an enormous amount of oregano, this will probably work for you as well.

Gardening Mistake #12: Forgetting About Garden Maintenance

If I had to pick one gardening mistake that I consistently make, it would be this one. I tend to live and let live with my garden which is not the best way to grow enough vegetables to eat, and especially not if you’re planning on using them for canning (such as canning homemade tomato sauce).

In order for a garden to thrive, it takes continued maintenance and care. You can plant it and forget it, but you won’t achieve maximum potential. You can also end up with a host of issues like pests, mold, and overgrowth.

A major lack of maintenance that we’ve committed is growing tomato plants without staking or pruning. Our tomato plants last year appeared to be one the healthiest tomato plants I’d ever grown, but we only got a handful of tomatoes. The problem was they weren’t getting enough sunlight and they took over the garden choking out other plants. We should have staked them when they were little and got them off the ground and growing upright towards the sun. This year we did stake our tomatoes and we have a whole bunch of tomatoes that we’re just waiting to ripen.

Here is some regular garden maintenance you can do to ensure that your garden stays happy and healthy:

• Prune
• Water
• Weed
• Mulch
• Fertilize
• Harvest

Gardening Mistake #13: Having No Plan to Keep Out Pests and Critters

We live in Pennsylvania next to the woods. We have an issue with critters.

Last year we set up a partial fence around the parameter of our garden but we didn’t get it finished. At first, I thought the animals would leave it alone. I was wrong. They did not. They ate everything, including our hot pepper plants which frankly was a bit of a surprise to me. Every time the hot peppers would start to establish themselves, something would come and eat the tops off. Some wild animal was willing to burn its mouths to establish its dominance in my yard.

This year Ned finished the fence and we’ve had a much better time keeping the animals away. (With the exception of my Brussel sprout plant that a deer ate by reaching over the fence and eating the top off every night).

Keeping out wild animals is one thing, but keeping out pests is another. This topic can become a bit more controversial since there are some who are totally fine with using pesticides in the garden and others that want to keep things as organic as possible. I fall into the organic side of the spectrum and try to avoid using pesticides in the garden. It’s one of the reasons I choose to garden, so it isn’t something I really want to concede on.

On the other hand, if you’re unable to protect your garden from invasive pests, it’s understandable why you’d turn to commercial pesticides.

For those who want to keep it natural and organic, there are some options.

1. Choose plants that aren’t prone to pests. This would include things like garlic, onions, rhubarb, or radishes. You may also be able to purchase plants that have been cultivated to resist pests in your area.
2. Plant things that repel pests. Certain plants actually repel pests from your garden. Examples include basil, lavender, rosemary, and marigolds.
3. Keep your garden healthy. A healthy plant is naturally more resistant to pests.
4. Use physical barriers to keep pests off. We had a real problem with our Brussel’s sprouts plants and worms. Next year, I’d like to try using a net (or floating row cover) to keep out these pests.
5. Plant diversely and attract beneficial bugs. Planting diversely will attract beneficial bugs to your garden. I also recommend planting flowers that will bring in other beneficial bugs and insects.
6. Remove pests by hand. There are some pests that are large enough that they can be removed by hand. Tomato hornworms would be a classic example of this.
7. Make an organic spray or use Neem oil. I haven’t had much experience with this, but there are a lot of tutorials online for homemade natural organic sprays that are meant to kill or repel pests. Neem oil is often used by organic farmers as an insecticide spray.

Gardening Mistake #14: Improperly Watering

Improperly watering is another mistake that many gardeners make.

It’s easy to forget about your garden when life is busy. While you can’t do anything about the weather, you can take care of your plants when the weather is dry and they’re going to get parched. You don’t need to water every day, but you can tell that your plants need some help when the ground is dry and the plants are at risk of wilting.

When you do water your plants, water them at the base of the plant and water them deeply. Providing a good bit of water every few days as opposed to a little water every day will help your plants develop deep strong roots.

Originally I had said not to water your plants during the day because you risk scorching them. Many sources now say this is a myth and that it doesn’t matter what time of day you water your plants. I would say watering them when you can is better than not watering at all, regardless of the time of day.

However, I would say it’s important to try to water at the base of the plant. Water on the leaves of the plant can lead to things like fungal infections which can be very detrimental to the plants. They don’t absorb water through their leaves, so a good soaking at the bottom of the plant will give it what it needs.

Gardening Mistake #15: Harvesting at the Wrong Time

If you’re new to gardening, you may not have a good sense of when it’s time to harvest your produce. Different plants. have different harvest times, so familiarize yourself with each type you’ve planted.

As an example, tomatoes are ready to harvest when the tomato is fully ripe and slightly soft when you press on them. You can pick them a bit early and let them ripen off the vine, but they do best when they’re able to fully ripen on the vine. Onions are ready to pull up when their tops fall over and become limp (or you can pull them up earlier if you like green onions as much as I do. Which is a lot).

Each plant has its own harvest time, so spend some time researching the plants you’ve chosen.

Get Your Hands Dirty and Get Started

I’ve given you a long list of things you can do wrong in the garden, but nothing beats trying things out for yourself and just getting started. Despite the many gardening mistakes we’ve made, we’ve also enjoyed lots of wonderful produce that we’ve been able to enjoy and we’ve often had enough extras to can or freeze and eat later.

Don’t let these common gardening mistakes stop you from getting started in your own garden. Pretty soon you’ll be the expert telling other people the best methods you’ve used to grow amazing vegetables in your garden.