After nearly two months of waiting for my carrots to mature, I was disappointed when I finally had my first bite. They were not juicy and sweet but rather bitter, and some even tasted like soap. I needed to find out where I went wrong to keep it from happening again.
Here are 8 reasons why your garden carrots aren’t sweet:
- Growing temperatures are too high
- Plant stress
- Harvesting too early
- Improper storage after harvesting
- Exposure to ethylene gas
- The carrot variety is naturally unsweet
- Poor handling during harvest and transportation
- Aster Yellows disease
Carrots have different tastes for various reasons. Sometimes there are multiple causes of the problem. I’ll explore why carrots get bitter in detail and offer solutions to the challenges.
1. Growing Temperatures Are Too High
The sweet taste in carrots is usually due to a perfect balance between terpenoids and the sugars in the root. Terpenoids are naturally occurring metabolites that plants produce. In carrots, terpenes influence the taste and flavor.
Carrots thrive when the temperatures are low, usually around 60°F- 67°F (15.5°C – 18.3°C). Terpenoids are produced when carrots start growing. When the temperatures remain constant, the carrots will have enough sugars to balance the terpenoids. These carrots are usually sweet and juicy.
When carrots grow in hot temperatures (80°F/26.6°C and above), they don’t produce enough sugar, so the terpenoid levels will be higher. Additionally, hot summer nights also cause carrots to lose moisture. In the process, the carrots lose sugars. The result will be bitter carrots.
The best time to plant carrots is during spring, but you need to ensure your timing is right. They need to mature before summer comes along.
If your area has a short spring season, grow carrot varieties that mature quickly. You can also plant carrots in fall if your area experiences mild winters. However, the carrots will freeze when temperatures fall too low, so you must harvest them before the first frost.
2. Plant Stress
Stressful growing conditions cause carrots to produce phenolic acid. Plants use this chemical compound to defend against parasites, pathogens, and predators. Phenolic acid also contributes to the carrots’ color.
When carrots grow in stressful conditions, they react by producing high quantities of phenolic acid, which results in a bitter taste. Such carrots will also have an off-color. For example, some carrots are pale, while others may be discolored.
If you want your carrots to be sweet, you need to eliminate all sources of stress to the plant. Ensure you remove weeds before they damage the roots. You should also control pests and diseases, water the carrots, and fertilize them.
This Down To Earth All Natural Fertilizer (available on Amazon.com) is organic and rich in beneficial bacteria. It stimulates root growth and optimum plant development. Besides its positive effect on the plants, this fertilizer encourages soil colonization. This will result in increased crop yields of superior quality.
3. Harvesting Too Early
Most people harvest carrots early, while others wait for too long. The challenge is sometimes it is difficult to tell carrots are ready, especially if you don’t have a record of when they are likely to mature.
Since carrots start producing terpenoids when they start germinating, it takes time for them to make enough sugar to balance the terpenoid. When you harvest the carrots early, the terpenoids in the carrots may be too high. The result will be bitter carrots.
Carrot varieties mature at different times. Some mature after 50 days, others 80 days, while some even take 96 days to mature. Carrots grow faster in warmer months than in cooler temperatures. So, you need to take this into account when harvesting carrots.
In hindsight, I think I didn’t pay attention to the carrots I planted and when they were due for harvest.
This video analyzes why home grown carrots are sometimes bitter and what you should do to have sweet, juicy carrots.
How To Tell Carrots Are Ready for Harvest
Carrots are ready for harvest in the following conditions:
- The tops are 1-6 inches (10cm-15cm) high. You can get them as baby carrots at this stage, but it is also the ideal time to thin and space them. Give the remaining carrots at least 3 inches (7cm) spacing so they can grow bigger.
- Carrots grow for 3-4 weeks after thinning. Ensure you give them plenty of water in the last month of growth.
- Different carrot varieties have different top lengths. Find out how tall the top gets for the different carrot varieties at maturity.
- A mature carrot has a diameter of 1 inch (2.5cm). Varieties, such as Imperator and Chantenay, are naturally bigger.
Carrot Varieties & Maturity Period
The chart below breaks down many carrot varieties, along with the length of time before they are classified as baby and full-size carrots.
| Carrot Varieties | Baby Carrots | Full-size | Height |
| Adana F1 | 44 days | 58 days | 6-7 inches (15 – 18cm) |
| Bolero | 56 days | 66 days | 6-7 inches (15 – 18cm) |
| Napoli | 40 days | 50 days | 10-12 inches (25.4 – 30.48cm) |
| Canberra | 80 days | 96 days | 18 – 20 inches (45.72 – 50.8cm) |
| Culinary blends | 60 days | 70 days | 10 – 12 inches (254 – 30.48cm) |
| Deep Purple F1 | 60 days | 72 days | 7 – 8 inches (18 – 20cm) |
| Istanbul | 60 days | 75 days | 9 – 11 inches (22.86 – 27.94cm) |
| Scarlet Nantes | 65 days | 75 days | 6 – 8 inches (15 – 20cm) |
| Parano | 50 days | 65 days | 6 – 7 inches (5 – 18cm) |
| White Satin | 55 days | 70 days | 8 inches (20cm) |
| Merida | 200 days | 240 days | 6 – 12 inches (15 – 30cm) |
Most carrot varieties will be okay for another 2 – 3 weeks in the ground after maturity. However, if they stay any longer, they will become woody. It is best to harvest the carrots as soon as they mature.
4. Improper Storage After Harvesting
Poor storage can turn sweet carrots bitter. Before harvesting carrots, you need to know how much you consume and how long you are likely to keep them in the refrigerator. Since carrots can remain in the ground for a few more weeks after maturity, it may be better to harvest what you need.
However, you shouldn’t leave them in the ground for too long. You’d rather harvest all the carrots and use long-term storage methods, such as canning, or take them to the farmers market.
Here’s how to keep carrots fresh and crispy:
- Remove the greens because they will compete with the root for moisture. Unfortunately, the greens always win, so your carrots will not have any moisture left if you refrigerate the carrots with the green top for a long time. If you don’t have the time to remove the green top immediately, you can leave them on for a few days, but no longer than a week.
- Put the carrots in perforated plastic bags. This will allow the carrots to breathe and, at the same time, retain moisture. Perforated plastic bags will keep carrots fresh for at least four weeks when refrigerated.
- Allow the carrot to dry completely before storage. Washed carrots have a higher moisture level, which increases the likelihood of mold growth and decay of carrots.
When storing carrots for a long time, you should;
- Chop, blanch, and freeze the carrots.
- Can the carrots.
- Store the carrots in the vegetable drawer instead of plastic bags to keep them from decaying.
5. Exposure to Ethylene Gas
Ethylene gas causes carrots to produce more terpenoids, even after you harvest them. Most fruits naturally release ethylene gas during the ripening process or when there is physical damage to the fruit.
This is why you are sometimes told not to store certain vegetables and fruits next to others because it affects the ripening process. Ethylene gas can change the texture, color, and ripening process, not just of the fruit itself but any vegetable or fruit placed close to the one releasing ethylene gas.
Apples and pears have high concentrations of ethylene gas, while cherries and blueberries produce very little ethylene gas. Avoid placing your carrots close to apples and other fruits that release high levels of ethylene gas. Whenever possible, keep carrots away from fruits to ensure their taste is not altered.
6. The Carrot Variety Is Naturally Unsweet
Some carrot varieties naturally have high concentrations of terpenoid. Purple carrots are not as sweet as most orange varieties. They have a peppery flavor, and are dark purple or reddish-purple with a yellow or orange core. These carrots have at least 20% less sugar.
Some carrot varieties with a bitter taste include Cosmic Purple, Purple Dragon, and Purple Haze.
7. Poor Handling During Harvest and Transportation
Carrots that are exposed to mechanical stress, whether you have harvested by hand or by machine, tend to have a bitter taste. Exposing carrots to shaking in a transport simulator causes them to produce more ethylene gas. They also lose some sugars through respiration.
8. Aster Yellows Disease
Carrots with aster yellows also turn bitter. Aster yellows is caused by phytoplasma, a bacterium transmitted by the aster leafhopper. Some of the signs that your carrots have aster yellows include;
- Excessively hairy, tapered roots.
- Pale color.
- Bitter flavor.
- Yellowing leaves.
- Carrots will be small in size even at maturity.
- Deformed carrots.
