Grow Big Sweet Carrots

Carrots are picky! Plant them in soil that is too heavy and they come out stubby. Plant them in too much shade and they are all top with a thread-thin root. If you don’t do everything just right, some of them can come out of the ground looking downright pornographic. (Seriously, who knew carrots could grow in such anatomically correct ways?) In this article I share a collection of the absolute best growing tips from gardeners across the internet when it comes to growing these popular veggies. Here is how to grow big, sweet carrots:

Carrots like daytime temperatures in the low 70’s and night time temps that are dropping to 55°F or cooler. The seeds can germinate in temperatures ranging from a chilly 45°F to a balmy 85°F. They may be grown in the early spring in your zone but many US gardeners sow them in the fall where cooler temps allow them to stay in the ground and sweeten through a couple of frosts.

Carrots grown in anything but the fluffiest, most aerated soil will come out small, stubby and/or appearing deformed. They are very sensitive to soil consistency and being crowded by weeds or other carrots can stunt them.

Carrots are Soooo Picky About their Soil!

Seriously. These fussy little roots like extremely loose soil. Like the lightest, fluffiest, most aerated soil you can hand craft for them.

Hand Mixing Soil for Growing Carrots

“Hand crafting” your future carrot crop’s soil is not a joke – I use a kitchen colander or soil screen to sift store bought organic compost to get the absolute finest texture for my carrots. I then mix it by hand with good quality play sand in equal parts until I have enough to fill a deep, 3 gallon, 5 gallon or 7 gallon grow bag. One 50 lb bag of play sand is usually enough to fill ONE of the 7 gallon grow bags or three of the 3 gallon bags when mixed with compost. Repeat this soil mixing for however many grow bags of carrots you want to have that season. Note that a 7 gallon grow bag filled with soil will weigh around 50 pounds so opt for the 3 or 5 gallon size if this is too heavy for you to move. (Affiliate links.)

Both of these options work but I found a kitchen colander sifts faster! Carrots don’t like a wood chip texture in their soil so I want the mulch-like compost pieces removed.

How store bought compost looks after passing through a soil sifter or colander. It is a very fine, fluffy, crumbly texture.

Play sand and sifted compost in buckets before mixing. I do roughly 1 part play sand to 1 part sifted compost.

Here is how the grow bags look after being filled with the sand & compost mix. I’m experimenting to see if carrots can tell the difference between 60% compost (largest grow bag) and 50% compost (two smallest bags on the right).

Keep It Clean

You do NOT want any manure that is too fresh to be in the carrot growing soil. I prefer to use very well aged compost for my carrots, which I then finely sift. There should not be any obvious chunks of poo from any animal in the compost you want to use for carrots. Because we eat the root of the carrot – and kids sometimes gobble them down fresh from the garden – you may find it best to use only well aged compost and play sand as your growing medium. I also prefer to grow them in fabric grow bags because it allows me to control how “clean” the soil is that I start with.

Bags & Buckets: The Secret to Long, Straight Carrots

Your carrots need a minimum of ten inches of incredibly loose, soft soil all the way to the bottom of their bucket or grow bag. If you give them this, they will reward you with (mostly) picture-perfect roots. I use 7 gallon grow bags which are 13 inches deep, 5 gallon grow bags which are 12 inches deep and 3 gallon grow bags which are 11 inches deep. (I am experimenting with 2 gallon grow bags, which are only 8 inches deep, to see if carrots will still grow to a usable size.)

The largest grow bag is 7 gallons. Three 3 gallon grow bags are shown next to a 2 gallon grow bag being used as an experiment. 1 extra large bag of organic compost and two 50 pound bags of play sand were required to fill these all up.

The Burlap Trick for Getting Carrot Seeds to Germinate

Carrot seeds are itty bitty tiny. They need consistent moisture in order to germinate but will completely wash away in the smallest trickle of water. To combat this, follow these steps to use garden burlap to your advantage:

1. Make sure your screened compost + sand mixture is watered and moistened BEFORE adding the carrot seeds.

2. If you plan to add a fertilizer into the soil, do it now. I use Big Ass Carrot fertilizer, mixed by hand into the top two inches of the grow bag soil.

3. Sow the carrot seeds carefully on top of the sandy compost. There is no need to bury them or sprinkle soil over the seeds in any way – the burlap will take care of covering them.

Carrot seeds are so tiny that it is hard to see the dozens of them on the wet sandy compost surface in this image.

3. Place a piece of burlap over the carrot seeds. This can be as easy as placing a square of burlap over the bucket or fabric grow bag or spreading a length of burlap over the garden bed. Use clothes pins to clip the burlap into place over the bucket/bag so there is an inch of room (or more) between the burlap and soil surface. The burlap is going to act as both a shade cloth and a type of cover that will not crush the seedlings.

4. Water OVER the burlap, getting it wet and letting the water strain through. It will stop the water from splashing the teensy carrot seeds out of the way and keep them uniformly moist while also allowing airflow.

5. Leave the burlap in place for the 6-10 days carrots need to germinate, watering it when the burlap is dry to the touch, usually every day, until the carrot seeds germinate and green seedlings are seen.

6. Once the carrot seedlings are up, remove the burlap and lay it out to dry in the sun. The burlap square can be re-used for multiple growing seasons if kept dry in storage.

7. Thin the carrot seedlings to the strongest growing 1 seedling every 1-2 inches.

Phosphorous Needed

When carrot seeds germinate, they need phosphorous to help them establish strong roots. If nitrogen is too high, they will stop growing. This is another reason that fresh, un-composted poop is a bad idea around your carrots; it simply has way too much nitrogen. Properly aged compost is an excellent source of phosphorous. Additional sources of phosphorus I use are the liquid fish foliar feed and “Big Ass Carrots” organic fertilizers mentioned below. (Affiliate links.)

Mix this powdery organic fertilizer with your soil BEFORE sowing carrot seeds. Use 1 Tbsp for 3-5 gallon grow bags and 2 Tbsp for 7 gallon grow bags, lightly mixed into the first two inches of soil. This small bag holds about 27 Tbsp of fertilizer and is easy to store. This carrot fertilizer also works for potatoes.

Calcium Hungry Carrots

Carrots benefit from calcium and magnesium fertilizers. Adding egg shells to the soil does not work, they need the calcium in a form they can immediately absorb. I use liquid Cal-Mag as a foliar feed to ensure I get large carrot root development.

Organic Carrot Fertilizers that Work!

This is the foliar feed recipe I use on my carrots, potatoes, onions, peppers, tomatoes and all of my garden veggies to get incredible results. The plant uses exactly what it needs and the foliar feed liquid that falls to the ground nourishes nearby soil microbes, which in turn boost nutrients that are available to the plants.

I add 1 Tbsp liquid fish foliar feed plus 1 Tbsp liquid organic kelp plus 1 tsp of Cal-Mag to a 2 gallon watering can and fill to the top with water. I then deliberately water the leaves of my vegetable plants for explosive growth.

In a 2 to 2.5 gallon watering can (I use Behrens) combine 1 Tablespoon Trident’s Pride Fish Foliar Feed, 1 Tablespoon Organic Liquid Kelp and 1 teaspoon Cal-Mag. Exact measurements are not needed – just eyeball it as your pour it into the bottom of an empty watering can then fill with water to mix the solutions. Use this as a foliar feed by deliberately watering the leaves of your plants in the morning. Plants will absorb the nutrients within 15 minutes. Works beautifully on all vegetable plants as well as onions, herbs, flowers, flowering shrubs and vines.

If you would like to qualify as 100% certified organic, opt for this organic Cal-Mag product.

No Need to Over-Feed

Once your carrot seeds have germinated, they appreciate regular watering, needing it daily in hot weather, and a foliar feeding 1 to 2 times per week. Carrot seedlings should have 3 or more real leaves (the ones that look feathery) before you begin foliar feeding them.

The carrot seedlings in the center pot have multiple feathery leaves and are old enough for foliar feeding.

Watering Needs Vary

Carrot seedlings need constant, comfortable moisture in order to germinate. The top of the soil should NOT dry out. Many gardeners use a piece of wood or burlap to cover their carrot seeds for the first 7-10 days. The soil should stay constantly moist but never soggy with standing water. If growing in fabric bags, place them in a large terracotta saucer or pan of water if they are drying out too quickly. I keep mine in a Gorilla Garden Cart.

Once the carrots are up and growing multiple-leafed tops, they need deep watering that is less frequent but the soil should be kept comfortably moist. Giving less water more frequently is ideal for carrots if the weather is warm or the top of the soil seems to be drying out between watering.

Hot Weather Tip: If you are sowing carrot seeds and it is still 100°F outside, keep the carrot grow bags in your garage! They do not need sunlight to germinate, only warmth, but they MUST have consistent moisture. The warmth of your garage will speed germination and it will be easy to reach them for their twice a day sprinkling of water.

Grow Big Sweet Carrots funny leg — This pair of carrot “legs” is a G-rated example of what happens to carrots that are not thinned. You’ll notice the carrots to the immediate left and right grew larger as well as straighter, which makes them easier to both scrub and peel for kitchen use.

Seedling Thinning Required

Carrot seedlings need to be thinned to 1 seedling every 1-2 inches so they do not grow in crowded conditions. Crowded carrots are skinny carrots at best. At worst, they go positively pornographic, meaning you’ll uproot some curvy lady shapes and…more masculine looking individuals. Use very loose, aerated soil and thin the seedlings if you want long, large, straight carrots. If the local farmer’s market has a thriving inappropriately-shaped-foods business, don’t thin them. If thinning feels wasteful, you can use the seedling dibber that came in your garden set or a pencil to carefully prick out and re-plant the seedlings elsewhere in the soil if you’d like. It does not always work but is worth a try if thinning really bothers you.

These carrots are growing too close together and have weeds popping up. They need to be thinned and weeded.

Weeding Is Required

Tiny young carrot seedlings can be very easily crowded out by any weed growing nearby. Weed around them carefully, plucking weeds when they are still extremely small. You won’t grow big, sweet carrots if nearby weeds are sucking nutrients away from the carrot root!

How to Get a Longer Harvest

If you live in an area where you have a month-long window in which to sow your carrot seeds, consider sowing your first batch as early as possible followed by a second planting 3 weeks later. This allows you to extend your harvest instead of being overwhelmed with a number of carrots all at once. If you’re using grow bags, you can also experiment with planting dates and varieties to determine what works best for your area.

Keep Their Shoulders Covered

Carrot “shoulders” that pop up above the ground will turn green and bitter when exposed to sunlight. Cover them with compost as a mulch to prevent this.

Do not let your carrots flower or they become bitter. Clip the flower heads off as soon as you begin to see them develop. The carrot on the right has also developed green shoulders. These will taste bitter.

Do Not Let Carrots Flower

When carrot tops begin to flower, it can make the carrot bitter. Clip off any flower heads as soon as you see them (or anything resembling a flower head that begins to grow up) so your carrots stay sweet.

Purple, orange and yellow carrot varieties. Skinny carrots after 75-100 days of growing may mean they did not get enough phosphorus and calcium.

A Rainbow of Color

Classic orange carrots are likely to be the sweetest but there are so many colors to try! Yellow carrots tend to be more mild while purples can have a richer flavor. Colorful carrot seed mixes are fun or you can buy vibrant varieties individually. Scarlet Nantes is one of the most popular heirloom varieties for backyard gardeners because they produce well. Many people claim Kuroda carrots are the sweetest tasting they have grown. If you can’t decide, craft your own seed mix and try them all!

Carrots are not an easy beginner vegetable to grow. It requires skill and patience.

Patience Required

Most seed packets will tell you the carrots germinate in 7 days and mature in 70-75 days. Experienced home gardeners will encourage you to allow up to 21 days for your carrots to germinate in cool weather, to thin your carrots properly within 14 days of germination and then wait around 100 days. A light frost actually sweetens carrots so don’t be in a rush to pull them all. Fall planted carrots can stay in the ground until hard freezes solidify the ground. In zone 5-10 they can stay in the ground almost all winter, being pulled as needed in the kitchen. Just remember to clip any flowering heads you may see form in early spring.

Nothing tastes better than sweet carrots from the garden!

Grow Big, Sweet Carrots in Texas

I’m growing carrots in Magnolia, Texas zone 9a where carrot seeds should be sown September 1-31 but daytime temperatures are still sizzling hot, almost always 90-105°F. Keeping the seeds moist with daily watering is a must and morning + evening watering is likely required. I use fabric grow bags in a garden cart because I can move them around. Seedlings don’t need full sun so I place them in a spot where they will get some morning sun, filtered mid-day sun and afternoon shade. They germinate quickly, in about 4 days. Once they are established, I will let them have progressively more sun as October (and it’s 80-90°F days) passes. When the first cool fronts hit in early November, the carrot bags are moved to full sun on 70°F and cooler days so they can take advantage of the sunlight and better ambient temperatures. Seeds sown near September 1 reach 100 days after December 10 but I’ll ensure they experience at least one light frost before harvesting for kitchen use. The leafy carrot tops then go to the chickens.

A carrot experiment is currently underway in Fall 2023 to show how carrots grow with BOTH foliar feeding AND Big Ass Carrot organic fertilizer mixed into the grow bag soil. I’m also experimenting to see if carrots will grow in the eight inch tall 2 gallon grow bags. Check back for more updates!

I hope this article has helped give you some new techniques to use to grow big, sweet carrots in your garden!

Grow Big Sweet Carrots