Why Are Your Carrots Growing So Small? 6 Causes

Most people expect their carrots to be big and lusciously orange when they pull them from the soil, so it can be frustrating when they haven’t grown as much as expected. So, why are your carrots growing so small?

Here are the six leading causes of carrots growing too small:

  1. Heavy or clay soil
  2. Insufficient water supply
  3. Hot Weather
  4. Overcrowding
  5. Nematodes
  6. Rocky soil

This article will discuss these leading causes in greater detail, so keep reading if you want to learn more about why your carrots might be growing too small.

1. Heavy or Clay Soil

Carrots thrive in loose, well-drained soil. When soil is heavy and dense, your carrots will have difficulty moving and grow much slower. Additionally, the roots will look unsightly if the soil is too heavy. 

Clay soils are hard to work with because they retain water and block many vegetables from growing correctly. Root vegetables need loose, well-drained, and aerated soil, so you should always try to avoid your soil becoming too heavy if you’re trying to grow root vegetables.

One of the signs of heavy soil is carrots growing small. But if you’re still unsure whether your soil is too heavy or not, you should examine it. One thing you can do is pick some up in your hand. If it crumbles easily, it’s not heavy. It is heavy if it remains clumpy, even when you try to break it apart.

Heavy, clay soil is also much more challenging to dig into. If you find it strenuous to dig into the soil, there’s a high chance that it’s heavy rather than loose. 

The two leading causes of heavy or clay soil are:

  • Applying pressure on the soil when it’s wet (such as standing or walking)
  • Too much clay and not enough earthy materials

Applying Too Much Pressure on the Soil 

If you walk on your soil a lot, mainly when it’s wet, you will make it too compact; this eventually leads to a hardened, heavy soil that carrots cannot grow efficiently in. When soil is compacted, the particles are so close together that there is little or no pore space between them.

The soil also becomes harder to drain and aerate due to its density, affecting the growth of your carrots and other root vegetables.

To avoid soil compaction, you should avoid applying heavy pressure on the area, mainly when it’s wet; this includes standing, walking, or using heavy machinery like a tractor.

Too Much Clay and Not Enough Earthy Materials

Soil that doesn’t have enough organic materials will become heavy and dense, so you should fix this if you want to grow carrots or other vegetables that require loose soil. The best thing you can do to loosen clay soil is to add organic materials back into the soil, such as compost or peat moss.

Mixing sand in will also help improve drainage and aeration, but you would need to use a lot of it to have the right effect; this is why using organic materials is the best option. 

Although compost is the best organic and earthy material for carrot soil, you can use other materials, such as peat moss, manure, grass clippings, bark, and leaves. 

Another way to break up clay soil is to aerate it with a pitchfork. All you need to do is dig into the soil and break it up until you’ve broken up all the soil. This method is best for smaller areas because it can be time-consuming, especially if the soil is very dense and heavy.

2. Insufficient Water Supply

Carrots need a minimum of 1 inch (2.54 cm) of water every week, so it’s essential to water them regularly if you don’t get much rain in your region. If they don’t get watered enough, they won’t grow as big as they should. They may also develop into odd shapes and won’t be as enjoyable to eat (or look at) if they’re dehydrated.

Sprinkling a small amount of water over the carrots won’t be enough to keep them hydrated; you need to soak them so that the water can penetrate down to the roots. This is highly important because if the roots beneath the soil don’t receive any water, the carrots won’t grow big enough, and they may experience additional problems.

There are different ways to water carrots, and one of the best ways is to use automatic sprinklers. This way, you won’t have to remember to water them and risk dehydration if you ever forget. Of course, not everyone has sprinklers, so you can also water by hand.  

You may not need to water your carrots during the rainy season. If it rains heavily every day, you will risk over-watering your carrots by adding extra water. Over-watered carrots tend to fork and crack, so it’s always best to avoid over-watering.

You Generally Don’t Have to Water Carrots Every Day

Thankfully, carrots are low maintenance and super easy to grow once they’re in the right conditions. Since they require approximately 1 inch (2.54 cm) of water per week, there’s no need to water them every day. You can generally water your carrots once a week, making sure to drench them each time.

You can choose to water the carrots more frequently if the soil is quite dry. Dry soil is prevalent in warm regions that don’t get much rainfall during the summer, so it’s a good idea to water the soil more often if the weather is warm and dry.

Too Much Rain or Watering Can Cause Over-Saturation

Although carrots need water to grow and thrive, too much water can be a problem. Certain regions may experience heavy rainfall during the winter, for example, and this can often lead to over-saturated carrots.

To avoid this, you can shelter your carrots in a greenhouse or other transparent shelter during the rainy seasons. However, carrots grow best in cool weather, so you shouldn’t use a greenhouse if the weather is hot and the sun is shining. 

It would be best to cover the carrots with a transparent covering because they need direct sunlight every day (at least six hours) to grow. Carrots that don’t receive enough sunlight every day will experience growth problems and likely come out of the soil smaller than expected. 

You may not own a greenhouse or clear soil covering. If you don’t, you can cover the carrots with a non-clear cover once they’ve received at least 6 hours of sunlight during the day. If you’re expecting a lot of heavy rainfall during the night, you should consider covering your carrots before you go to sleep.

3. Hot Weather

Carrots germinate best in cool climates, with temperatures between 55 and 75 °F (13-24 °C). If the weather is too hot, particularly during germination, it could be causing your carrots to grow smaller than you’d like. 

If you live in a region with a hot climate during the summer, it might be a good idea to avoid planting carrot seeds at the peak of summer; planting in hot weather could cause them to grow slower and smaller.

Hot weather is one thing, but if the region is dry, your carrots will be even more likely to grow small without proper care. As I mentioned earlier, carrots need a lot of water and loose soil to grow big. Therefore, growing them in a dry and hot climate will require more effort on your part.

You must water your carrots adequately to make up for the dryness and lack of rainfall. It’s best to water your carrots in the evenings with cold water because this helps cool the soil for the night. 

Be Sure to Mulch the Soil if the Weather Is Extremely Hot

A layer of mulch over your soil will help prevent overheating, so it’s a great idea to do this if you want to insulate the soil and prevent your carrots from growing small in hot weather.

Since it will help keep the soil cool, carrots will be more likely to grow bigger. You can use bark mulch to insulate the soil. Soil is more likely to become hardened in hot weather, so it’s also essential to keep it loose and aerated as much as you can.

How Hot Is Too Hot for Carrots?

Temperatures above 80 °F (27 °C) should be considered too hot for carrots. However, the recommended soil temperature for carrots to grow is between 60 and 70 °F (16 and 21 °C).

If you try to grow carrots in temperatures above 80 °F (27 °C), they will likely turn out smaller than you’d like. They also won’t be as high quality or vibrant as carrots grown in cooler weather.

To avoid hot weather affecting your carrots, you should try to grow them in late fall and early spring; this will give you the best possible results and lessen the chances of underground carrots.

4. Overcrowding

Carrot roots that don’t have enough space to grow may end up stunted and deformed. It is pretty easy to accidentally plant your carrot seeds too close together because of how small they are, so you should always keep that in mind when planting.

When you sow carrot seeds too close together, the roots won’t have enough space as they grow down. They will grow into each other and often won’t grow to their maximum size, giving you small, disappointing carrots. 

So, if you notice your carrots are disappointingly small after harvesting, you should consider how much space you left between each seedling. If you didn’t leave enough space, that could be the reason why your carrots are so small.

At least 3 inches (7.62 cm) of space between each seed is a reasonable distance and should eliminate any overcrowding issues. Of course, smaller carrots require less space, and larger carrots require more than 3 inches (7.62 cm). It all depends on how big your carrots are!

If you have already planted your carrots and are only now realizing that they’re overcrowded, you don’t have to worry too much. Luckily, you can fix the issue without having to waste all your crop. 

So, how do you fix this overcrowding? Well, it’s a method called thinning, and I will talk more about it below!

What Is Carrot Thinning?

Carrot thinning is the act of removing some of the carrot seedlings to give more space to the other, more mature carrot seedlings. It is carried out when carrots seeds have been sown too close together, a common occurrence in the carrot-planting world.

Thinning is best carried out once germination has occurred, and you should repeat it a few weeks after the first thinning (approximately four weeks after).

How to Thin Carrots

For the first thinning, you should remove every second seedling or remove the puniest-looking ones. You should leave approximately 1.5 inches (3.81 cm) between each seedling during the first thinning because the plants are tiny at this point, so they don’t need much space yet.

To remove the little seedlings, all you need to do is grab them with your fingers and gently pull them out. They should come out easily if your soil is soft and loose (which is the best type of soil for carrots).

You should wait approximately four weeks after completing the first thinning to carry out the second thinning; this gives the carrots a chance to grow some more before removing anything. 

Like the first time, you should remove every second seedling or every seedling that looks puny. When you pull out the seedlings, you’ll notice that they will have grown into miniature carrots. Luckily, the carrots are edible at this point, so you won’t have to throw out the ones you’ve removed. 

You can use these newly removed carrots in plenty of dishes once they haven’t been damaged, so be sure that you’re extra careful when removing them! Additionally, you can attempt to replant them if you want them to grow to regular-sized carrots.

5. Nematodes

Nematodes are parasites that live in the soil. If they are present in your soil, they will usually damage the roots of your carrots, causing stumping and forking. They are most commonly found in the upper layers of the soil; this is how they can do so much damage to carrots and other plants.

Since they damage the roots, they will cause your carrots to appear small and underdeveloped.

Common symptoms of nematode damaged carrots include:

  • Deformed roots
  • Knotted roots
  • Stumped roots
  • Hairy roots
  • Discoloration
  • Thicker skin
  • Forked roots

Carrots are highly susceptible to nematode attacks, and they tend to attract them more than many other vegetables and plants. The best way to avoid nematodes is to rotate your crops each time you plant more (or rotate them once a year). 

So, if there’s a specific area where you always plant your carrots, you should plant them in a different location after a year (or less). This will significantly reduce the chances of nematode damage and is a cost-effective preventative measure.

It can be challenging to fix nematode-infested soil, especially across a large section. A method that many people use to combat nematodes in the soil is solarization

Soil solarization uses the heat from the sun to kill bacteria and parasites within the soil. It’s an eco-friendly way to kill nematodes because it doesn’t involve any harmful chemicals, and it is an entirely natural process.

How to Kill Nematodes Using Soil Solarization

Before carrying out soil solarization, you should make sure to remove any weeds or old plants. You should also drench the soil in water before applying the cover, which will help with heat retention.

To kill nematodes using soil solarization, you should completely cover the affected area with a transparent material that absorbs the heat from the sun. This will trap the heat within the soil, and the heat will then kill the nematodes. It’s best to use transparent plastic material when covering the soil.

Once you have covered the affected soil, you should ensure that each side of the plastic is buried in the soil. This will ensure the heat stays trapped inside the soil, which will be more likely to kill the parasites.

You should leave the plastic cover over the soil for at least four weeks, but ideally more than that. The longer you leave the plastic cover over the soil in the heat, the higher the chance of the nematodes dying.

Although soil solarization works well and is highly cost-effective, it should only be carried out during the summer when the weather is hot, and the sun is shining all day. Solarization won’t work during the winter because it relies on heat and sunlight. 

So, if you have a nematode problem during the winter, unfortunately, you’ll need to wait until summer to use the solarization method.


If you can’t use the soil solarization method or don’t want to use it, you can also try using nematicides to kill the nematodes. Nematicides are chemicals that kill or disturb nematodes in the soil.

Nematicides only work in the top layers of the soil, so some nematodes may end up escaping deeper down and survive the chemicals. Additionally, they aren’t environmentally friendly due to the chemicals, so solarization is more eco-friendly. 

If you choose to use a nematicide, it’s essential to follow the instructions on the packaging. Some products will tell you to leave a few weeks between using the nematicide and planting your seeds to avoid poisoning, so you must pay attention to the instructions.

You should also keep animals and children away from the soil once you’ve applied the chemicals.

If you’ve taken the necessary steps to combat nematodes and notice that your carrots are now growing to a bigger size, you’ve likely fixed the problem and can enjoy your freshly grown carrots!

6. Rocky Soil

Since carrots grow downward in the soil, it’s essential to ensure your soil isn’t rocky and uneven. You want the carrots to grow smoothly with no interruptions, and rocks or stones in the ground will get in the way of your carrots and can cause stumping and forking.

If your carrots come out of the soil looking more petite than you expected, it could be due to rocky soil. Be sure to examine the soil to see if there are many stones and bumps. It would be best to try and dig down a bit and review the soil with your hands. 

The ideal soil for carrots should be light and primarily sandy, and it should easily crumble between your fingers. If you notice it’s rocky and doesn’t crumble so easily, your soil is likely too rocky for carrots to grow well.

The soil will generally become rocky naturally as the ground beneath it moves upward, but there are ways to fix it.

Fixing Rocky Soil

If you think rocky soil is why your carrots are growing small, you should try to fix it as soon as possible. 

Here is how you can fix your rocky soil:

Remove Large Rocks

Remove any visible oversized rocks and stones from the soil. Firstly, you’ll want to remove any large obstructions. Big or giant rocks are a big no-no when it comes to the soil for carrots, so you should get rid of them straight away.

Clear Small Rocks

Remove any smaller rocks and debris. Using a rake to remove stones and debris helps break everything up and creates smoother soil. 

Add Organic Materials

Apply organic materials on top of the soil. Once you’ve removed as many smaller stones as you can, you should layer organic material on top to push the rockier ground downward.

You should apply approximately 4 or 5 inches (10.16-12.7 cm) of organic material over the soil. The best materials include grass clippings, well-rotted manure, and peat moss. 

Consider a Raised Bed

Another viable option would be to plant your carrots in a raised bed instead of directly in the soil. You can choose to make your own raised bed, or you can choose to buy one. You can make your own out of wood or plastic, which is handy if you have any leftover materials lying around.

Once you’ve bought or made your raised bed, you can fill it up with the required materials. It would be best if you filled it up with organic materials, such as grass clippings, leaves, and well-rotted manure. Since you’ll be using it for carrots, you’ll want to make sure the soil is light and aerated rather than heavy and dense.

Since raised beds are not connected to the soil, there will be no chance of rocks or stones getting in the way and causing growth problems for your carrots. Many people choose to use raised beds for this reason, and it truly is one of the best ways to grow big, healthy, and delicious carrots!

Alexander Picot

Alexander Picot is the founder of TheGrowingLeaf.com and its lead content writer. He created the website in 2022 as a resource for horticulture lovers and beginners alike, compiling all the gardening tips he discovered over the years. Alex has a passion for caring for plants, turning backyards into feel-good places, and sharing his knowledge with the rest of the world.

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