Why Are My Peppers Growing So Slow? (3 Ways to Speed Up)


Are you worried about pepper plants that are growing slower than you expected?  If so, you are probably wondering what the problem is, and how to fix it.

So, why are your peppers growing so slow?  Peppers grow slowly in cool temperatures – they are a tropical plant, and grow best at daytime temperatures of 70 to 85 degrees Fahrenheit (21 to 29 degrees Celsius).  Peppers will also grow slowly due to improper watering, soil problems, or transplant shock.

Of course, there are also some less common reasons that peppers will grow slowly.

In this article, we’ll look at several reasons that peppers grow slowly and how to avoid these problems.

Let’s get started.

Why Are Your Peppers Growing So Slow?

There are many possible reasons that your peppers are growing slowly.  One of the most common is low temperatures (cold soil), so we’ll start there.

pepper plant
Low temperatures will slow down pepper growth.

Low Temperatures

Peppers are a warm weather crop – in fact, they are a tropical plant.  As such, they are accustomed to growing in high temperatures and warm soil.

In fact, according to Clemson University:

“Peppers (Capsicum annuum) are warm-season plants that grow best at temperatures of 70 to 85 °F during the day and 60 to 70 °F during the night. Peppers generally require a long growing season and grow very slowly during cool periods.”

https://hgic.clemson.edu/factsheet/pepper/

As such, it would be a mistake to transplant peppers outside too early in the season.  Otherwise, they will be exposed to cold that will harm the plant and stunt its growth.

A frost (temperatures below 32 degrees Fahrenheit or 0 degrees Celsius) will spell the end for pepper plants.  Even more mild temperatures of 55 degrees Fahrenheit (13 degrees Celsius) or below will slow the growth of mature pepper plants.

frost
A frost will spell the end for pepper plants, whether it is in the spring or fall.

According to the University of Maryland Extension, you should start pepper seeds indoors 8 to 10 weeks before the last frost date.

You can use this tool from the Old Farmer’s Almanac to find the last frost date for your area.

Choosing when to plant peppers can be a tricky.  They need warm soil and they also need enough time to grow and produce mature fruit before harvest.

If you plant too early, your peppers face the danger of late spring frost.  If you plant too late, your peppers face the danger of early fall frost.

In an area with a short growing season, you may be in a tough spot.  In that case, there are some steps you can take to keep pepper plants warmer.

You can learn more about how to protect pepper plants from cold in my article here.

Improper Watering

Even if temperatures are warm enough for peppers, they may still suffer from improper watering.  This could mean either too much water or not enough.

Over Watering

When peppers are over watered, their roots do not need to grow and expand to find more water.  When you provide peppers with too much water, they “have it easy” and fail to build up a strong root system.

If dry weather comes along and you forget to water, a pepper plant with weak roots will have a very difficult time surviving.

In extreme cases, over watering will keep the soil too wet for too long.  This can lead to a lack of air in the soil, which will eventually cause root rot.

root rot
Root rot causes roots to turn brown and mushy.

To avoid this problem, always feel the soil with your fingers before watering.

If the soil is still moist at a depth of a few inches, you can wait to water.  If the soil is dry at a depth of a few inches, give the plants a deep drink of water.

Don’t look for a set schedule for watering, since the plant’s water needs vary depending on many factors, such as:

  • Temperature
  • Humidity
  • Plant size
  • Whether you mulched around the plant

If your soil drains poorly, it can make the problem of over watering even worse.  You can learn about how to improve soil drainage in my article here.

Under Watering

Pepper plants will grow slowly if they lack water.  Dry soil can also cause nutrient deficiencies, which will stunt growth and leave plants susceptible to pests and diseases, such as blossom end rot.

Try not to let your soil take on that dusty desert sand appearance.  Check the soil daily and water when needed.

dry soil
Don’t let you soil get this dry!

If dry soil persists, you can learn more about how to treat it in my article here.

Soil Problems

Even with warm temperatures and proper watering, pepper plants will grow slowly if they face soil problems.  Two common soil problems are pH and nutrients.

Soil pH

When soil pH is too low or too high, nutrients become unavailable to plants, as you can see in this chart from Research Gate.

For example, the availability of phosphorus drops rapidly as soil pH drops below 6.5.  In fact, the University of Massachusetts Extension suggests a pH in the range of 6.5 to 6.8 for growing peppers.

If you find that your soil is too acidic (low pH), you can raise it by adding lime (calcium carbonate).  If your soil is too basic (high pH), you can lower it by adding elemental sulfur.

calcium carbonate
Lime will raise soil pH, but get a soil test before adding anything to your garden.

However, you should always get a soil test before adding any treatments to your garden.  Otherwise, you might be trying to solve a problem that you don’t even have!

You can learn more about how to do a soil test in my article here.  A soil test will tell you the soil pH, but also the levels of different nutrients in your garden.

Nutrients

Even at a proper soil pH, certain nutrients may be lacking in the soil.  For example, a lack of nitrogen can lead to slow growth for many plants, including peppers.

Without enough nitrogen, pepper plants may fruit and flower early, which will slow their growth.  According to the Michigan State University Extension:

“Many annual fruiting plants like peppers will slow vegetative growth once they set fruit.”

https://www.canr.msu.edu/news/its_time_to_review_your_pepper_fertilization_program

According to the Michigan State University, to prevent this problem:

“enough fertilizer has to be applied prior to fruit set so sufficient plant growth is produced prior to adding a fruit load.”

https://www.canr.msu.edu/news/its_time_to_review_your_pepper_fertilization_program

This means that you will need to add nitrogen to your soil prior to planting peppers.  You can do this using compost, manure, or other soil additives.

compost bin
Compost will add some nitrogen and other nutrients to your soil.

You can learn more about how to provide nitrogen for pepper plants in my article here.

Just remember that it is possible to over fertilize plants.  Too much nitrogen all at once can burn plants, whether it comes from “hot” manure or artificial fertilizers.

Transplant Shock

If you know you are providing the proper temperature, water, pH, and nutrient levels, then transplant shock might be the cause of slow growth in your pepper plants.

Transplant shock can happen when the roots of plants are damaged during transplant.  It can also happen due to a sudden change in environmental conditions.

Plant Roots
When plant roots get tangled, they are more likely to get damaged during transplant.

Transplant shock occurs when a plant is moved from indoors to outdoors.  This transition often leads to a drastic change in:

  • Light
  • Temperature
  • Water
  • Soil
  • Exposure to elements (wind, rain, insects)

Transplant shock takes an even greater toll on pepper plants.  According to the University of Massachusetts:

“Peppers are slow growing and are susceptible to transplant shock.”

https://ag.umass.edu/home-lawn-garden/fact-sheets/peppers-growing-tips

To avoid the problem of transplant shock for your pepper plants, be sure to harden them off properly.  Hardening off is the process of making gradual changes so that plants can get used to outdoor conditions.

Just be careful not to expose pepper plants to cold air for too long.  According to Cornell University:

“Over-hardened plants grow slowly after transplanting.”

http://www.gardening.cornell.edu/homegardening/scene9c8a.html

Other Reasons

There are a few other reasons that your pepper plants will experience slow growth.  One of them is simple, but easy to overlook: a lack of light.

Lack of Light

In order to grow, all plants need light.  Some plants need more light than others, but all of them use light to produce energy by photosynthesis.

Pepper plants need full sunlight (8 hours or more per day).  Without enough light, peppers will not be able to produce enough energy, and their growth will be stunted.

sunlight through forest
Peppers need full sunlight to grow properly.

The reasons that a pepper plant might not get enough light include:

  • Shade from nearby trees – a spot in the garden may be sunny in the spring, but shaded in the summer after the leaves grow back on nearby trees.  Plan ahead when deciding where to put your garden and where to plant your peppers!
  • Shade from other plants – if you grow peppers next to other plants that grow taller and faster (for example, tomatoes and beans), these other plants can prevent the peppers from getting enough light for growth.
  • Growing indoors – when growing indoors, pepper plants might not get enough light from a window or skylight alone.  Even if you are using grow lights, they may not be bright enough or offer the type of light your plants need.

Pests and Diseases

Pests and diseases can also slow the growth of peppers.  In severe cases, they can spell the end for your plants.

For example, aphids are small insects that like to suck the juices from the stems and leaves of plants, including peppers and tomatoes.

aphids
Aphids are an insect pest that sucks the juices from plant leaves and stems.

With a severe infestation of aphids, the insects will rob a pepper plant of the water and nutrients that it needs for growth.

You can learn more about how to prevent aphids in my article here.

Variety

Finally, the variety of pepper plant you choose will play a role in how fast it grows.  To get an idea, you can check the days to maturity on the seed packet or online.

There is a pretty big variance in how long it takes pepper plants to grow to the point where you will get mature fruit.

purple bell peppers
Sweet peppers will grow much faster than hot peppers.

For example, sweet peppers can take anywhere from 60 to 90 days to produce fruit.  On the other hand, it can take 150 days for hot peppers to produce fruit!

It will take even longer if you are growing from seed.  You can learn more about when pepper plants produce fruit in my article here.

Conclusion

Now you have an idea of why your peppers are growing so slow.  You also have some ideas on how to avoid the common causes of slow growth.

I hope you found this article helpful.  If so, please share it with someone who can use the information.

If you want to read some of my most popular posts, check out the “Best of GreenUpSide” page here.  Enjoy!

~Jonathon

jonathon.david.madore

Hi, I'm Jonathon. I’m the gardening guy (not guru!) who is encouraging everyone to spend more time in the garden. I try to help solve common gardening problems so that you can get the best harvest every year!

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