Even the pickiest eaters can be convinced to enjoy a carrot with dinner! So these root vegetables are a must-grow in any home garden patch.
You don’t need a ton of experience to cultivate high-quality carrots. The most important thing is ensuring that the carrots have plenty of space to grow within the soil. The second most important thing, at least in my experience, is providing the right type of nutrition at the right time of year. For that, a little expert advice can go a long way in getting you the results you crave.
Choosing Fertilizers For Carrots
If you’re in a hurry to select a fertilizer, then here are my two top picks for the best fertilizer for carrots. Otherwise, be sure to read the entire article for all the best advice on different fertilizer options plus when, how, and why you need to fertilize carrots.
Best Slow-Release Granules
Burpee Granular Organic Food 4-4-4
Evenly balanced NPK and slow releasing granules, suitable for carrot plants as well as many other vegetable growing needs.
Best Organic Fertilizer
Down to Earth Organic Fertilizer 5-4-2
100% organic with all-natural ingredients, designed to encourage strong and vigorous root growth and development.
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Carrot Fertilizer N-P-K Ratio
To determine whether or not a particular fertilizer is suitable for carrots, look for the N-P-K ratio and the rate of release. The N-P-K ratio is a sequence of 3 numbers that show you how much nitrogen, phosphorus, and potassium are inside. This will be clearly stated on the product packaging, for example, 5-3-5
For carrots, I recommend selecting a slow-release fertilizer with a balanced NPK ratio such as a 4-4-4 or similar. Applying early in the growing season will allow the green vegetative tops of the plant a chance to get well established. It is however important not to choose a high nitrogen fertilizer (e.g. 10-2-2), as this will lead to excessive vegetative growth at the detriment to root development.
As the season progresses you can consider fertilizing carrots with root development in mind. So a feed with bonemeal is a good option, offering phosphorus and potassium for healthy root growth.
I would emphasize that if the soil is too rich carrots can have a tendency to fork into peculiar shapes, So apply your fertilizer early in the season as part of your standard vegetable bed fertilizer application. Then once mid-summer with a low dosage to support strong root development.
Soil pH And Nutrients
Carrots will tolerate a soil pH between 5.5 and 7.0. For most varieties, the ideal pH is between 6.0 and 7.0.
It’s easy to mistake unbalanced soil for a regular nutrient deficiency. If you’re working to address malnutrition in your carrot crop, I always recommend conducting a pH test before applying further amendments.
Bonemeal Fertilizer for Carrots
Bone meal is high in phosphorus which helps promote healthy root growth. It is quite low in nitrogen and does not contain potassium.
If you know your garden’s soil profile and amend it with other nutrients as necessary, bone meal can be the core of your carrot fertilizing routine.
Fish Fertilizer for Carrots
When selecting fertilizer for carrots, it’s important to distinguish between fish emulsions and cold-pressed fish fertilizers. The former is very high in nitrogen and, in my opinion, not suited for carrots’ nutritional needs unless your soil is nitrogen deficient and needs attention.
Fish fertilizer on the other hand is a great source of phosphorus that won’t burn your carrots. Thus, fish fertilizer is a great way to boost strong and healthy root growth and a great ‘booster’ to use one or twice mid-season if you feel your carrots are not developing roots as well as you would expect. Think of this as a corrective feed application, if things aren’t going to plan.
Granular Vs Liquid Fertilizer
There’s a time and place for both granular and liquid fertilizer when growing carrots. However, I think granules are the more versatile of the two.
Granules can be applied in the spring before planting carrots. They can also be added to the soil via side-dressing throughout the growing season.
Liquid fertilizers, on the other hand, are only really effective for mid-season feedings. I don’t recommend relying on liquids to prepare the soil in the spring.
Foliar Fertilizer for Carrots
Not everyone knows that plants can absorb many nutrients through their leaves as well as their roots. For carrots, however, I find that foliar feeding makes a minimal difference in performance. While you can apply diluted liquid fertilizer to carrot tops without much issue, it really isn’t necessary.
Synthetic Vs Organic Fertilizer for Carrots
While some people feel more comfortable using exclusively organic fertilizers for edible plants like carrots, I’m a strong proponent of using what works best for you and your garden.
As long as you are choosing quality products and applying them according to the manufacturer’s guidelines, there is little need to worry about synthetic fertilizers and their potential effect on your carrot crop.
6 Best Fertilizers For Carrots
Rest assured, carrots are pretty easy to fertilize in the garden. There are a number of great options — many of them organic — out there that will meet the basic needs of carrots.
Below you’ll find my personal favorites and how I recommend using them for the best carrot harvest possible.
Pros
- Listed for organic production by OMRI
- Releases nutrients immediately and over several months
- Contains a variety of nutrients and microbes
Cons
- Can increase leafy top growth
Burpee All-Purpose Plant Food is an excellent organic granular formula to keep on hand for all veggies and herbs including carrot plants.
In the vegetable garden, timing is everything. One of my favorite features of this fertilizer is that it delivers nutrients instantly as well as over time. A single dose can feed the soil for up to 3 months (though Burpee recommends applying this fertilizer every 2 months for the best results).
This is a great fertilizer to get new plantings off to a flying start at the beginning of the growing season when everything is getting established. Plus, it’s a relatively low ratio of NPK and – when used in conjunction with the manufacturer’s guidelines – will not cause fertilizer burn.
How To Use: To feed carrot plants throughout the growing season, I recommend side-dressing with up to 1 cup of fertilizer per 10 feet.
Pros
- Designed for use on rooting crops
- Suitable for use throughout the growing season
- Improves root growth potential and crop size
Cons
- ‘Organic’ odor
This slow-release organic fertilizer is specifically designed for use on rooting vegetables. It helps to stimulate root growth and improve crop size and yield thanks to NPK ratio balance as well as the addition of beneficial bacteria and mycorrhizal fungi.
The soil in which I plant my carrots tends to dry out quickly causing cracks to appear in my carrot crops. But NPK ratio in this feed with decent amounts of both phosphorous and potassium means that my carrot crop has a strong root system and improved tolerance to drought.
For that reason, I’m happy to put my trust in their products. Not only because their products are 100% natural and OMRI certified, but because I’ve never had a bad crop having used this or any other products in their range.
How To Use: Mix up to 5 pounds per 100 square feet of soil to prepare new garden beds. Side-dress established carrots with 2 ounces of fertilizer. Use from the start of the growing season and throughout. Repeat every 4 months.
Pros
- Made with high-quality cold-pressed fish
- Ideal for mid-season feeding
Cons
- Has a slight fishy smell
Neptune’s Harvest is a great brand for cold-pressed fish fertilizer. While many emulsion-style fertilizers contain too much nitrogen for carrots, that’s not the case for this liquid formula!
I recommend using this fertilizer throughout the growing season as you notice your carrots’ growth lag. It will work best when paired with an organic, slow-release fertilizer earlier in the spring.
This is a concentrate, so make sure you dilute it before applying. I like to add this fertilizer to a hose-end sprayer but you can also mix it in a watering can for smaller areas.
How To Use: Mix up to 1 ounce of fertilizer per gallon of water. Fully saturate the soil around your carrots.
Pros
- Made from registered organic ingredients
- Does not have an offensive odor
- High in phosphorus
Cons
- Not a source of potassium
If you don’t already have a go-to bone meal brand, I recommend this formula from Espoma. It’s an excellent soil amendment for the start of the growing season, especially if your garden soil needs an extra dose of phosphorus.
Since root vegetable plants such as carrots benefit from phosphorus for their ‘below ground’ development, this bone meal may be the only supplement your garden needs to produce big, juicy carrots. In most cases,
Where a phosphorous deficiency isn’t an issue, however, I recommend pairing it with other fertilizers that address your soil’s specific nutrient profile.
How To Use: Mix into the soil prior to sowing carrot seeds. Apply up to 10 pounds per 100 square feet.
Pros
- Made with certified organic and non-GMO ingredients
- Versatile enough to use on many veggie plants
- Won’t cause fertilizer burn if used as directed
Cons
- Does not have a strong odor
Another of my favorite organic vegetable fertilizers is made by Dr. Earth. And with its 4-6-5 NPK formula, this is a granular fertilizer with the right proportions but not overly concentrated N-P-K ratio.
While there are many excellent organic fertilizers available to choose from, this one stands out because it is also certified non-GMO and designed to be people- and pet-safe. (Of course, you should always use caution when applying and storing any fertilizer around kids or pets!)
How To Use: The recommended application rate for established plants is up to ¾ cup of fertilizer per 12 feet. If your carrots are not planted in rows, apply up to 1 cup per 10 square feet of garden area.
Pros
- Balanced source of macronutrients
- Formulated for edible plants
- Supports root development
Cons
- Excessive use may damage carrot crops
Osmocote’s Smart-Release fertilizer is a nice alternative to aged manure or compost for early spring soil amendment. While the latter options are still my favorite, I can also admit this fertilizer has a lot to offer.
Since this formula is quite concentrated for carrots, it’s important to measure carefully and provide plenty of water. Personally, I like to add this type of fertilizer early and let it break down in the soil for a couple of weeks before planting if possible.
How To Use: Apply at a rate of one (included) scoopful per 10 feet of garden row. Mix into the top layer of soil and water.
How To Fertilize Carrots
Supplementing the soil with an organic or slow-release granular fertilizer prior to planting carrots is far more important than any mid-season feeding. This preparatory application is all many gardens need to produce large, delicious carrots.
Pockets of granular fertilizer too close to carrots can burn the taproot. Any fertilizer applied before planting should be evenly mixed at least 3 or 4 inches into the soil. I recommend leaving a small margin around each plant when side-dressing carrots.
Fertilizing Carrots in Pots & Containers
All of the advice given for in-ground carrots also applies to those growing in containers. My one piece of advice specifically for container-grown carrots is that you’ll likely need to fertilize more often since the soil can’t hold onto nutrients for as long.
Avoiding Fertilizer Burn
Fertilizer burn is rarely a problem when growing carrots because they don’t need much nitrogen in the first place. I most often see this issue occur when gardeners apply fresh (rather than aged) manure or compost to the soil.
Even if fertilizer burn doesn’t occur, excess nitrogen will create misshapen or stunted carrot roots. Overfed carrots also don’t taste as good!
When To Fertilize Carrots
You can mix a slow-release fertilizer or aged manure into the soil in the spring. Alternatively, you can add compost or manure to the soil in the fall so it has time to start breaking down before spring.
How Often to Fertilize
I prefer fertilizing based on the height of carrot tops versus following the calendar. It’s best to apply a liquid fertilizer or side-dress with granules when the tops reach 3 to 4 inches tall. You can fertilize again when the tops are 6 to 8 inches tall.
Fertilizing Carrots Final Thoughts
A rich, slow-release fertilizer is going to be your greatest tool for raising carrots in the garden.
One of the best fertilizers for carrots is Burpee Natural Purpose Granular Organic Food 4-4-4. It’s an organic formula that will set your garden up for months of good nutrition and microbial health.
Best Slow-Release Granules
Burpee Granular Organic Food 4-4-4
Evenly balanced NPK and slow releasing granules, suitable for carrot plants as well as many other vegetable growing needs.
For stronger roots and bigger, better carrot crop harvests, I recommend Down to Earth Organic Bio-Live Fertilizer.
Best Organic Fertilizer
Down to Earth Organic Fertilizer 5-4-2
100% organic with all-natural ingredients, designed to encourage strong and vigorous root growth and development.
