The 13 Most Likely Reasons Your Jalapenos Didn’t Grow This Summer

Written by Jennifer Hollohan
Updated: August 22, 2023
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You spent so much time and effort planting your jalapeno pepper seeds, ready for a rich harvest at the end of the season. Perhaps you had visions of roasted jalapenos, fresh salsa, or cowboy candy at the end of the summer. Unfortunately, your jalapenos didn’t grow. That is a heartbreaking outcome and can feel very frustrating. Thankfully, there are some common causes for this outcome. Below we will cover the 13 most likely reasons your jalapenos didn’t grow this summer so you can get a killer harvest next year.

1. Poor Germination

Not all seeds will germinate properly. And that doesn’t necessarily mean you did anything wrong. It is just part of nature. However, it is frustrating when seeds don’t germinate. So taking proper steps before you start your seedlings will help.


You can avoid a lot of heartache by testing the seeds before planting them. Pop your jalapeno seeds into a cup of water and leave them for 15 minutes. Scoop off any that remain floating at the end of the test, as they are likely not viable. Feel free to plant those that sink to the bottom.

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Another good option is to add a heat mat underneath your soil blocks to help provide adequate warmth.

Cherry tomato seeds in plant starter pot tray with soil, close up. Dwarf bush tomato seeds "red robin" for small container garden. Early spring planting in greenhouse or window sill. Selective focus.

Not all seeds will germinate properly.


2. Not Enough Sunlight

Proper light exposure is critical for indoor seedlings and once you transplant your jalapeno peppers. Established plants need 6-12 hours of sunlight daily. But seedlings need even more, that is, 14-16 hours of light daily. 

When they don’t get enough light exposure, the result is weak plants, fewer flowers, and less fruit.


When starting seedlings indoors, get a grow light to help supplement the natural light. Leave it on for at least 14 hours every day.

Before transplanting, take some time to determine which part of your garden gets plenty of sunlight. 

Pick the sunniest spot to place your pot if growing in containers. The good news is that you can move containers as needed throughout the growing season.

sunlight​ very​ hot​. summer​ season

Proper light exposure is critical for indoor seedlings.

©enjoy photo/

3. Transplant Shock

Most jalapeno pepper plants do best when they get started indoors and then transplanted. However, if you rush to get your plants in the ground once they are large enough, you could inadvertently kill them. Seedlings started indoors are a little more delicate and are not used to the harsher outdoor environment.


Harden your jalapeno plants off properly over a week or so. 

Preparing garden bed for planting

Harden your starts off before transplanting them.

©Михаил Руденко

4. Low-Quality Soil

Jalapeno plants (and all peppers) need high-quality soil to thrive. Too much soil compaction reduces the amount of necessary nutrients reaching your jalapeno plant’s roots. And poor drainage leaves the roots sitting in a moist environment that can result in yellowing leaves, poor growth, or root rot. Additionally, if your soil is lacking nutrients, it will stunt the plant’s growth.


Amend your soil before the planting season to improve the overall quality, allowing more oxygen and nutrients to reach the roots of your jalapeno plant.

Aerate the soil before planting season so the roots can grow better.

Get a soil test done in the off-season. The results will help you determine which amendments are most appropriate.

Top view of soil in hands for check the quality of the soil for control soil quality before seed plant. Future agriculture concept. Smart farming, using modern technologies in agriculture

Jalapeno plants (and all peppers) need high-quality soil to thrive.

©Deemerwha studio/

5. Planted Too Closely Together

It is so tempting to plant your beloved jalapenos more closely together to try and boost your harvest. Unfortunately, the reality is that the exact opposite will happen if you place them too closely together. Doing so prevents proper air circulation and may reduce sunlight exposure, stunting the plant’s growth.


Plant each jalapeno starting at least 18 inches apart.

Gardener planting broccoli seedlings in freshly ploughed garden beds. Organic gardening, healthy food, nutrition and diet, self-supply and housework concept.

Planting jalapenos too closely together prevents proper air circulation and may reduce sunlight exposure.


6. Improper Watering

Pepper plants need consistently moist (but not damp) soil, especially when they are first developing. When jalapeno plants dry out, their growth becomes stunted, and fruit doesn’t develop properly. Additionally, the less water you give, the hotter the peppers become. On the other hand, too much water prevents oxygen from reaching the roots.


Water deeply when the top 1 inch of the soil dries out.

Amend the bed before planting each year to help aerate the soil.

Mulch around the base of the plant to retain soil moisture.

Photo of a black soaker hose with two holes for watering lying on the ground under a strawberry plant. Drip irrigation system in a garden.

Pepper plants need consistently moist soil, especially when they are first developing.


7. Lack of Pruning

Contrary to popular belief, pruning does not harm your pepper plants. In fact, if you fail to prune your pepper plants back, they will not get enough air circulation between the leaves. In turn, this will lead to increased susceptibility to diseases and pest pressure.


Pinch back new growth to direct the plant upward so it becomes bushier.

Jalapeno pepper tree with group of hanging fruit.

Make sure to prune jalapeno plants to develop bushy plants.

©Quang Ho/

8. Disease

Jalapeno plants are susceptible to disease, especially in hotter and humid climates. This vulnerability grows if the plants are situated too closely together or have not gotten pruned. Taking these preventative measures is a good first step. But it may not solve all the problems. You could need to take additional steps if the disease sets in.


Do not practice overhead watering, especially in the evening or humid climates. Water from below or install irrigation.

Take the time to practice proper spacing.

Remove diseased parts as soon as you see them to prevent any spread.

Discard the whole plant, if necessary, to save others from suffering the same fate.

Diseased pothos leaves

Watch for signs of disease, like yellowing leaves.


9. Pests

Sometimes pest pressure can result in unsightly plants. But other times, pest pressure can overwhelm the plant and prevent it from growing properly. Keeping a close and watchful eye on your jalapeno plants will help you stop problems before they become severe. Growing pest pressure could result in stunted growth, lack of fruit production, or death.


Perform routine inspections to look for holes, discoloration, chewed leaves, and eggs on the underside of leaves.

Practice companion planting to reduce pest pressure.

Use organic insecticidal soap to kill off unwanted visitors.

Milkweed aphids. Aphis nerii

Pests, like the aphids pictured, can plague your jalapeno plants.


10. Flowering Too Early

Those first few flowers that show up on your jalapeno plants are exciting! After all, it means an early harvest, right? Not necessarily. When your jalapeno plants start flowering too early, it could reduce overall pepper production.


Pinch off any early flowers (as hard as it is) until the plant grows larger to help promote a larger harvest.

Jalapeño pepper on plant.

Pluck any early flowers to ensure an abundant jalapeno harvest.

© Ward

11. Bad Companion Plants

While companion planting can help your plants thrive in many cases, other times, plants don’t get along at all. You may hinder its growth f you plant a foe too close to your jalapeno pepper plant.


Research the plants you want to plant near your jalapenos to ensure they will get along.

Jalapeño peppers growing

Plant the right companions for your alapeño peppers.

©Gatis Grinbergs/

12. It’s Too Hot or Too Cold

Jalapeno plants can’t tolerate high heat even though they love warm weather. Your plants will suffer if you have extended stints above 85 degrees Fahrenheit. Likewise, excessive cold or wet environments will stunt the plant.


Protection is your best bet – on both ends of the spectrum. Provide shade cloth during periods of heat and protection during cold spells.

Shade cloth over hydrangea in garden

Use a shade cloth to help protect your jalapeno plants during hot weather (like this one over a flower).


13. Improper Fertilization

Jalapeno plants need nutrient-rich soil to thrive. Their growth (and your harvest) will suffer if they don’t get that. On the flip side, too much fertilizer applied too frequently can also damage your plants. 


Test your soil at the start of the season to discover any deficiencies. Use targeted fertilizer throughout the season to help fix that.

A seed and fertilizer spreader sitting out on a lawn

Make sure to fertilize your jalapeno plants properly for them to thrive.


Summary of the 13 Most Likely Reasons Your Jalapeno Plants Didn’t Grow

1Poor Germination
2Not Enough Sunlight
3Transplant Shock
4Low-Quality Soil
5Planted too Closely Together
6Improper Watering
7Lack of Pruning
10Flowering too Early
11Bad Companion Plants
12It’s Too Hot or Too Cold
13Improper Fertilization

The photo featured at the top of this post is © Svetlana Foote/

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About the Author

Jennifer Hollohan is a writer at A-Z Animals, where her primary focus is on gardening, mammals, and travel. Jennifer has over twenty years of writing experience. She holds a Master of Arts in Anthropology from the University of Colorado at Boulder, which she earned in 2005, and is a Herbalist. Jennifer lives in Colorado with her family. She loves hiking, admiring wildflowers, gardening, and making herbal tea.

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