After teaching gardening for over 20 years, I can confidently say that many gardeners in colder climates like mine have difficulty growing peppers. The problems often begin in late winter when gardeners are starting peppers indoors and continue into the summer when they wonder why are their pepper plants not growing.
I used to struggle with growing peppers as well, until I figured out the various factors that can negatively affect peppers. Once you can identify and solve for these issues, you’ll be well on your way to abundant and colorful pepper harvests every summer.
Let’s get started exploring the reasons why your pepper plants might not be growing as well as you’d like.
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Why Are Your Pepper Plants Not Growing?
Unfortunately, there isn’t one simple answer to this question. You’ll have to be your own garden detective and look for clues using the following factors. We’ll also talk about the solutions once you identify the problems.
Pepper Plants Not Growing – Factor #1: Lack of heat
First, whether we’re talking about pepper plants that are still indoors or pepper plants that have already been planted in your garden, what pepper plants love the most is heat!
Starting peppers indoors
I’ve been growing peppers in my garden successfully for many years, but I’ve had trouble during the seed starting process with getting them to germinate. And in the past, when they did germinate, the plants grew very slowly.
Peppers like very warm temperatures for germination. A soil temperature of 85 degrees F is ideal. This high temperature is difficult to provide during the seed starting process in most homes during winter.
I’ve found that providing supplemental heat to my peppers during germination ensures a quick and even sprouting of almost 100% of the seeds I planted. I also leave the heat on the peppers after germination to coax the plants to grow more quickly.
Over the years I’ve had the best success with using either a seedling heat mat underneath newly planted seed trays or an electric soil warming cable buried in the soil of the tray.
Read my in depth article about starting peppers indoors for the exact process I use that yields consistent results year after year.
Growing peppers outdoors
Once you plant your peppers in the garden, you’ll need nature to provide the plants with the heat they need to grow well. Peppers grow best at daytime temperatures of 70-80 degrees F. The ideal temperature range for plants to set fruit is between 75-86 F.
Pepper plants are very sensitive to low temperatures. They should not be planted in your garden until you’re certain the last frost has passed. It’s better to delay planting than risk death from frost. And I’ve found that my plants don’t grow very much in the cool spring weather, so there’s not much benefit to trying to get them out into the garden early.
If you’re not sure when to plant your peppers in your gardening zone, this article features a printable planting schedule and shows you how to figure out your average last frost.
If you live in an area where the summers are cool, you may have trouble growing peppers if you don’t have consistently hot temperatures. Daytime temperatures below 72 F will inhibit the plant from setting fruit well. Try using a greenhouse, low tunnel or high tunnel to trap in extra heat.
Pepper Plants Not Growing – Factor #2: Excessive heat or low temperatures.
Yes, peppers love heat, but, there is a point where it can cross the line into too much. When the temperature is above 90 F during the day, peppers often drop their flowers. The flowers are what turn into the fruit, so less flowers = less fruit. If your garden is experiencing an extended heat wave right around the time when your peppers are flowering, you may notice lower numbers of peppers on your plants.
On the flip side, if your garden is experiencing cooler than normal temperatures, less than 55 degrees F at night, while the plants are flowering they will also often drop their flowers. This unfortunate timing might result in less overall fruit to harvest.
Pepper Plants Not Growing – Factor #3: Lack of soil nutrients.
The health of your soil is one of the main factors that affects how successful your garden will be each season. In fact, you should be spending time and effort to build the best soil for a vegetable garden.
When your soil contains all of the nutrients the pepper plants need, they’ll grow larger and be more productive, the fruit they produce will be higher quality, and the plants will better resist disease and pest pressure.
If you keep puzzling over why are your pepper plants not growing, one of the first steps I would take would be to work some fertilizer into the soil around each plant. You’ll learn more about the best fertilizer for peppers later in the article.
Pepper Plants Not Growing – Factor #4: Sun
Peppers do best in full sun – eight or more hours per day. If your plants aren’t growing to full size or producing as much as you think they should, lack of sun might be the reason.
Relocate your pepper plants into a full sun area of your yard if possible. That’s the best option. If you don’t have a section of your yard with full sun, peppers might not be the best choice for your garden. Consider focusing on growing vegetables that need less sunlight: root vegetables like carrots and beets, and leafy vegetables such as spinach, salad mix, cilantro, and kale.
Jimmy Nardello’s Sweet Pepper – one of my favs!
Pepper Plants Not Growing – Factor #5: Variety
Vegetable variety is a very important ingredient in the success of your garden. And not all varieties are created equal! I find this to be very much true with peppers, especially sweet varieties.
Each year I grow around 35 pepper plants. I try new varieties every year in the hopes of finding new successes. More often than not, I’m unimpressed with the trials. Year after year, my two favorite sweet pepper varieties – Carmen and Jimmy Nardello’s – outperform all the rest. Without fail, both of these varieties produce reliable crops of beautiful, sweet red peppers.
None of my best performing varieties are bell peppers. I think that’s the most common mistake gardeners are making – trying to grow the bell peppers they see in the grocery store.
I haven’t had much success with them over the years, so I’ve abandoned that pursuit for one that’s much more successful – growing varieties that are all not bell peppers! Read all about my favorites and learn my best tips on growing sweet peppers.
My experiment with black soil coverings.
How to Make Peppers Grow Faster
I chuckled when I wrote this headline because who doesn’t want everything in our gardens to grow faster! Gardening in not for the impatient, that’s for sure.
To make peppers grow faster, you’ll need to provide more heat earlier in the season, and possibly the whole season, depending on what kind of climate you live in.
The most common options are black plastic, a greenhouse, or a low or high tunnel.
In my area of Wisconsin, many farmers use black plastic to grow peppers because it heats up the soil more quickly in our cooler climate. I’m not a huge fan of using plastic in the garden, but I did manage to find an old billboard that I use to cover the soil. I cut holes in the vinyl at every 18 inches, three rows to the bed, which is the spacing I use for my pepper plants.
I then planted a pepper in each hole. I’ve done some experiments where I planted half of my peppers in the bed covered in black plastic and the other half in a bed covered with mulch. I haven’t seen a remarkable difference between the two, but I’m going to keep experimenting.
If you’re lucky enough to have a greenhouse or a low or high tunnel, you may already be experimenting with growing peppers inside. This isn’t something I have experience with since our summers in Madison seem to be hot enough to get a good crop of peppers.
Best Fertilizer for Peppers
In general, the best fertilizer for peppers is what I recommend for your entire garden, no matter what vegetables you’re growing. I’ve found that most gardeners benefit from adding an organic garden fertilizer to their garden beds every time they plant. Even if you’ve ordered soil and installed a new garden, the soil might not be as healthy as it should be.
This is the simplest and saftest option. You shouldn’t be adding amendments willy nilly to your garden unless you’re educated about your soil and what each of those nutrients do. If you’re interested in the subject, you can geek out on soil nutrient issues (I have!) and travel down the road of getting an npk test to figure out the exact makeup of your soil.
Don’t overfeed your plants with nitrogen or your peppers will produce a lot of leaves but not much fruit. That’s why I recommend only using a complete organic garden fertilizer, unless you have soil test results in hand to support you making educated decisions about other actions to take.
One of my hot pepper varieties grew to almost the same height as me!
Pepper Plant Leaves Turning Yellow
While we’re on the subject of soil health, if your peppers aren’t growing well, you may notice that the pepper plant leaves are turning yellow. The most common reason for any leaves of vegetable plants turning yellow is lack of nitrogen.
Nitrogen is considered one of the most important nutrients for plant growth. Nitrogen is part of the photosynthesis process, which is responsible for giving plant leaves their green color.
In areas of my garden with poor soil, I have experienced yellowing plants. My advice is to work some complete organic fertilizer into the soil around each plant. Be careful not to add too much nitrogen or you could create an imbalance. A complete organic garden fertilizer will deliver a range of macro and micronutrients, not just nitrogen.
If nitrogen isn’t the culprit, it’s also possible your plants are deficient in magnesium or iron. This can also be the cause of pepper plant leaves turning yellow. A complete organic fertilizer will help address these nutrient deficiencies as well. Check the back of the fertilizer package before purchasing to make sure it contains magnesium and iron.
You should see improved plant health within a week or two of adding fertilizer. Sometimes it happens in mere days! Observe the new leaves growing from the plant to see if they’re a darker green. The yellowing leaves should also start to turn back to green.
If this doesn’t fix it after a few weeks, I’d suggest taking the next step of sending in a soil sample for an npk test to get a fuller picture of your soil.
Overwatering and underwatering can also cause the leaves of pepper plants to turn yellow. Overly dry soil can inhibit the roots’ ability to uptake nutrients from the soil. Roots also need air, so if your soil is soggy and never dries out, that will affect the nutrient absorption as well.
Most vegetable plants do best with about 1 inch of water per week, more if you have sandy soil. If it doesn’t rain around an inch during the week, water your plants deeply with a hose or install a drip irrigation system. Read more about the best ways to go about watering your vegetable garden.
As you can see, there are several factors that contribute to pepper plants not growing. Experimentation and observation are important parts of the gardening experience. As you improve your knowledge and skills around growing peppers, I feel confident that one of these years you’ll surprise yourself with a very successful season of pepper growing!
More Resources for Growing Peppers
Here’s the complete suite of pepper articles I’ve written over the years: