Why are my carrots so small? Here’s the quick answer.

Your carrots are small for one or more of the following reasons:

  1. You grew your carrots in heavy, compacted soil.
  2. Your carrots didn’t get enough water.
  3. Your carrots didn’t get enough sunlight.
  4. Your carrots received too much nitrogen.
  5. Your carrots were overcrowded.
  6. You harvested your carrots too soon.

I’ve had my fair share of failed carrot harvests in the past. Carrots are easy to grow once you understand how to grow them, but they’ll usually disappoint you if you drop some seeds in the ground and hope for the best.

In this post I’ll explain the most common reasons home growers end up with small carrots and I’ll tell you how to avoid making the same mistakes when you grow your next carrot crop.

why are my carrots so small

#1 – Don’t Grow Carrots In Compacted Soil

Compacted soil and carrots are not a match made in heaven.

Carrots need deep, loose soil, and if you want your carrots to grow well, you’ll need to do some “ground work”.

Compacted soil tends to be soil that has a high clay percentage. Even if you dig and work clay soil to loosen it up, once it gets wet, it begins to compact and carrots struggle to push through the dense soil.

Heavy soil can sometimes still give you usable carrots, though. You’ll get small, fat carrots because even though the carrots can’t grow as deep in heavy soil, as long as their roots can mine the soil for nutrients, they’ll make short stubby carrots.

(I’ve covered short fat carrots in another post, so if your carrots are small and stubby, there’s plenty of information there to help you fix your soil problems.)

Fix – Dig your carrot bed to loosen the soil and add compost.

How deep should you dig?

Find out the mature length of the carrot variety you want to grow and add another 2″ to 3″ (5 cm to 8 cm).

The longest carrot varieties are Imperator types. These carrots grow up to 12″ long (30 cm) and need a soil depth of 14″ to 15″ (35 cm to 38 cm).

To provide a better growing medium for your carrots, add compost to your soil.

Compost increases the organic matter in your soil. It adds fertility, improves drainage, and helps prevent compaction.

To make the addition of compost more affordable, dig out the soil from the rows where you’ll sow (or plant) your carrots. Rows should be around 18″ to 24″ wide (45 cm to 60 cm) for best results.

There’s no need to amend the soil between the rows, but that soil should be loose.

Drop the soil into your wheelbarrow (or a large bucket) and add the compost and mix it in with your hands.

Remove any stones you find as you mix the compost into the soil.

Before you put the amended soil back onto your carrot bed, carry out a squeeze test to evaluate the texture of your soil.

Here’s how to do a soil squeeze test

  • Pop some soil into a bucket and wet the soil enough to make it damp.
  • Scoop up a handful of soil.
  • Squeeze the soil in your hand to make a clump.
  • Poke the soil clump with your fingers.

If the clump holds together when you poke it, it’s still too heavy for carrots. Add some more compost.

You’ll know you’ve got a good soil texture for growing carrots when the clump holds its shape when you squeeze it, but falls apart when you poke it.

Before you put the amended soil on your carrot bed, work it through with your fingers so it’s nice and loose and free from big lumps. The extra time you take preparing your soil at this stage will pay dividends later on.

Put the soil back on your bed and place a marker on each row so you know where your good soil is.

#2 – Make Sure Your Carrots Get Enough Water

Don’t let your carrot bed dry out. Carrots like to grow in moist soil.

Fix – Water once or twice a week giving at least 1 inch of water.

If you’re growing carrots in soil with a good texture that holds moisture, it’s usually sufficient to water once a week, giving carrots 1 inch (2.5 cm) of water.

If your soil is sandy, you’ll need to water twice a week because sandy soil doesn’t hold water very well.

(Improve the water holding capacity of sandy soil by mixing in some compost.)

Keep an eye on the moisture level in your soil, especially during dry periods. It’s crucial to make sure that the soil doesn’t dry out! Carrots stressed by drought conditions will be small at harvest time and they tend to be bitter instead of sweet.

Do you know this famous nugget of gardening wisdom?

The best fertilizer is the gardener’s shadow

No, that’s not a brand of fertilizer. The gardener’s shadow is you.

When you’re out in your garden, sowing, planting, digging, watering, pruning, weeding and harvesting, you cast a shadow.

The more time you spend working in your garden, the more time your shadow is present.

When you’re in your garden every day, you notice when things are going wrong, and you fix problems before they get out of control.

For your carrots, you’ll cast your shadow when you pluck out weeds, and you’ll cast your shadow when you quickly push your fingers into the soil to check the moisture level 3 or 4 inches down.

If the soil is dry at that depth, you need to water again, even if you watered the day before.

We can use a rough watering timetable for the vegetables in our garden but that timetable isn’t set in stone because the dehydrating effects of the sun and the wind have an enormous impact on soil moisture.

Often soil that looks wet on the surface after you’ve watered is still dry a few inches down.

Never take a guess on soil moisture levels. Use your fingers to know for sure.

When you’re growing carrots in a dry climate, or during a dry, warm spell, a layer of mulch around your carrots will reduce surface evaporation and do wonders for the amount of moisture your soil can hold on to.

Mulch materials you can use include dry grass clippings, dry leaves, and straw.

#3 – Grow Carrots Where They’ll Get Plenty Of Sunlight

Carrots thrive in a sunny location. Sunlight is energy and when your carrots don’t get enough of that energy, they’ll produce small roots instead of long ones.

If your carrots grew in a shady spot, lack of sunlight is probably the reason they’re so small.

Fix – Make sure your carrots receive 6 to 10 hours of sunlight each day.

When you plan your vegetable garden, consider the mature height of the plants you want to grow and plant the taller crops where they won’t cast a shadow over your carrots.

Avoid planting carrots in areas where trees, buildings or fences will block sunlight.

#4 – Why Are My Carrots So Small? Nitrogen Could Be Your Problem

While carrots are growing, you only see the above ground foliage, you don’t see the growth of the carrots themselves down in the soil.

The foliage often looks fantastic, and all of that lush, green growth tricks you into believing that your carrots are growing like gangbusters under the surface.

But sometimes the abundant foliage is all you get and when you pull up your carrots they’re small and thin, and incredibly disappointing.

So what went wrong?

How can the above surface growth look so healthy while the carrots themselves are so small?

The answer lies in the nitrogen level in your soil.

Nitrogen is essential for plant growth, but carrots aren’t heavy feeders and too much nitrogen results in a forest of foliage above a crop of smaller carrots.

Excess nitrogen can also result in insect infestations and in a higher susceptibility to diseases.

Fix – Before you fertilize carrots, find out the nitrogen level in your soil, otherwise you’re fertilizing blind.

Use a DIY soil testing kit to find out your baseline nitrogen (N), phosphorus (P), and potash (K) levels.

If the soil test shows you’ve got sufficient nitrogen in your soil, then you won’t need to add any more for your carrots. Remember, too much nitrogen results in lots of leaf growth and small carrots.

When you do need to add fertilizer, look for a fertilizer with a 10 -10 -10 ratio. 10 -10 -10 is the carrot fertilizer ratio recommended by the Department of Horticulture at Iowa State University extension service.

#5 – Thin Carrot Seedlings Twice To Prevent Overcrowding

Carrots need room below ground to spread their roots, and their foliage needs room above ground to receive enough sunlight.

When carrots are crowded together, you’ll get a few big carrots and lots of small carrots.

Fix – Thin carrots twice.

Go through your carrots when they’re about 3″ (8 cm) tall. Remove the weakest carrot seedlings, leaving 3/4″ to 1.5″ (2 cm to 4 cm) between the remaining plants.

Thin your carrots a second time, 3 to 4 weeks later. This time, take out the weakest plants in the row, leaving 1.5″ to 3″ (4 cm to 7 cm) between the carrots.

The small carrots you pull out at this stage are the perfect size for a snack.

#6 – Give Your Carrots Time To Grow – Don’t Harvest Too Soon

Carrots are ready to harvest anywhere from 55 to 100 days after sowing. It all depends on the type of carrots you grow and your growing conditions.

You can’t tell when carrots are ready to harvest by looking at the carrot foliage. If you harvest too soon, your carrots will be small.

Fix – Don’t harvest until carrot shoulders are at least half an inch wide.

Close up view of carrot shoulders.
Carrot shoulders should be at least 1/2 inch wide before you harvest.

Before you pull up your carrots, brush away some soil with your fingers to expose the carrot shoulders (the top of the carrot).

Start harvesting your first carrots when the shoulders are at least 1/2″ (1.5 cm) wide. These will be baby carrots – super sweet and bursting with flavor.

Wait until carrot shoulders are roughly 1.5″ (3.5 cm) wide before you harvest your main crop.

Quick Recap

To get a good harvest of carrots, make sure the soil in your carrot bed is deep, loose, and able to hold moisture.

Keep the soil in your carrot bed moist, never let it dry out.

Plant carrots in an open, sunny location and don’t grow taller plants that will cast shade nearby.

Test your soil to find out the nitrogen level. Too much nitrogen produces lots of leaf growth but small carrots.

Thin carrots twice to give each carrot the room it needs to grow.

Check the width of your carrot shoulders before you harvest.

Thanks for reading: Why are my carrots so small. I hope this post helps you figure out what went wrong with your carrots so you can grow a better crop next time 🙂