8 Best Fertilizers For Herbs | How And When To Use

In culinary terms, herbs are aromatic leaves that add immense flavor to the dishes they’re used
in. Some of the most popular herbs (at least in the US) include things like basil, cilantro, oregano, thyme, rosemary, and chives.

It’s super common to see these plants all growing together outdoors in a vegetable patch or container, but they are also plants that can thrive indoors too.

Herbs are easy to grow but that doesn’t make them maintenance-free. In my experience, the most significant difference between a successful lush herb garden and one that falls short is nutrition…or lack of it!

Here are my personal tips for growing an herb garden you can be proud of, plus the fertilizers for herbs, I recommend most.

Best Fertilizers for Herbs

In a hurry? Here are the herb fertilizers I recommend most often:

Espoma Organic Indoor Plant Food 2-2-2

Best Organic Fertilizer for Herbs

Espoma Organic Indoor Plant Food 2-2-2

A fast-acting liquid concentrate feed. Great for edibles such as herbs because it’s 100% organic and has a perfect NPK ratio.

Dr. Earth Organic 5 Tomato, Vegetable & Herb Fertilizer 4-6-3

Best Fertilizer Granules

Dr. Earth Vegetable & Herb Fertilizer 4-6-3

Organic, slow-release granules that help to improve soil and can be used for a range of garden herbs and vegetables.  

Jobe's Herb Fertilizer Spikes 4-3-3

Best Fertilizer for Herbs in Pots

Jobe’s Herb Fertilizer Spikes 4-3-3

Convenient, mess-free fertilizing that has been specifically blended for herbs. Ideal for containers, or indoor grown plants. 

Choosing the Best Fertilizers for Herbs

It is true that most herbs can survive without the need for fertilizer, but whether they grow to their full potential without the addition of nutrients is a different matter. In my opinion, adequate nutrition is an excellent way to improve flavor and harvest output with minimal added labor.

Some herbs need far more nutritional support than others. Regardless of which herbs you plan to grow, I recommend choosing a low-concentration, balanced fertilizer when first starting out.

Fertilizer for Slow Growing Herbs

Many culinary herbs are native to the Mediterranean where they are accustomed to relatively dry, infertile soil conditions. 

It is easy to identify these slow-growing herbs by the presence of woody stems and thick, sometimes needle-like leaves. Popular examples include thyme, rosemary, sage, and oregano.

Fertilizer for Fast Growing Herbs

There are also plenty of herbs that grow quickly and are adapted to rich, moist soil. These herbs require a steady source of nutrition to support their rapid growth. 

In contrast to the slow-growing herbs I mentioned above, these tend to boast large, thin leaves on herbaceous stalks. Some examples include basil, cilantro, dill, and chives.

Herb Fertilizer N-P-K Ratio

The main thing that sets one fertilizer formula apart from another is something called an N-P-K ratio. This is a sequence of 3 numbers that represent the percentage of nitrogen, phosphorus, and potassium in the fertilizer.

For example, a fertilizer labeled 6-4-4 would contain 6% nitrogen, 4% phosphorus, and 4% potassium. 

I recommend choosing fertilizer with a relatively balanced N-P-K ratio to feed herb plants. While all 3 numbers don’t need to be identical to get good results, they should be very close to each other.

Nutrient Uptake & Soil pH for Herb Plants

Most garden herbs grow well in neutral or slightly acidic soil with a pH between 6.0 and 7.5.

Something to keep in mind is that an incorrect soil pH often manifests in plants as nutritional deficiencies. This is because pH affects how easily plant roots can absorb certain key nutrients from the soil. For the best results, I suggest looking up the ideal pH levels for the exact type of herbs you plant to grow.

Granular Vs Liquid Fertilizer

Whether to use granular or liquid fertilizer for your herbs is largely a personal choice. Most gardeners have a strong preference for one or the other, and they each boast their own pros and cons.

Liquid Fertilizer for Herb Plants

Liquid fertilizers excel at delivering nutrients quickly and efficiently. If you want to give your perennial herbs a jumpstart in early spring, a dose of liquid fertilizer may be the best option. It also works well as an extra source of nitrogen for particularly vigorous fast-growing herbs.

Slow-Release Fertilizer Granules for Herbs

Granular fertilizer is almost always my preferred choice when feeding garden herbs. It works well on both slow- and fast-growing herbs and carries less risk of fertilizer burn when measured properly.

Fertilizer Spikes for Container Herbs

These are another interesting option for container-grown herbs. Fertilizer spikes are essentially granules that have been pressed into a pellet or spike shape. Like granules, they release nutrients into the soil very slowly.

Synthetic Vs Organic Herb Plant Fertilizers

Personally, I feel comfortable using both synthetic and organic fertilizers on my kitchen herbs. But there are also many gardeners that feel differently (and that’s totally fine)!

At the end of the day, what matters most is that you are using and storing your chosen fertilizer according to the safety label. And it’s always a good idea to thoroughly wash your herbs before use, no matter what type of fertilizer you use.

Best Fertilizer for Herbs Reviews

Fertilizing herbs isn’t hard as long as you have the right tools at your disposal. These formulas are my personal favorites in terms of efficacy AND ease of use (regardless of experience level).

1. Espoma Organic Indoor Plant Food 2-2-2

Best Organic Fertilizer for Herbs

1. Espoma Organic Indoor Plant Food 2-2-2

Pros

  • Safe for indoor use
  • Includes a convenient measuring cap

Cons

  • Not a slow-release formula

A convenient option for indoor herbs is this liquid concentrate from Espoma. It’s organic and has a perfectly balanced NPK so you can be sure your herbs are getting the correct ratio of nutrients at any one time. 

I especially like that it contains a variety of nutrients and microbes your herb garden will love. Plus, it is safe for use in a home with pets or young children (regardless, you should always store fertilizer in a secure location).

While it can be a pain to fertilize small potted herbs growing somewhere like a kitchen windowsill, this fertilizer earns my recommendation because it’s super convenient to use. The bottle has a built-in measuring cap and can be stored in your pantry or broom closet between feedings. 

How To Use: Dilute up to ½ capful of fertilizer per quart of water. Saturate the soil fully.

Pros

  • Feeds herbs and vegetables for up to 2 months
  • Promotes a healthy soil biome
  • Made with organic, feed-grade ingredients

Cons

  • It May have a strong odor

One of my favorite fertilizers for kitchen herbs comes from Dr. Earth. It’s an organic formula containing beneficial microbes that support plant health and can improve soil quality over time.

While this fertilizer isn’t perfectly balanced, the N-P-K ratio is close enough that you can use it on both slow- and fast-growing herbs. But you may want to supplement particularly vigorous herbs with an extra dose of nitrogen in the spring.

If you’re still unsure about applying fertilizer to your edible herbs, this formula is a great starting point. It’s made from feed-grade ingredients that are certified organic by multiple institutions.

How To Use: To feed in-ground herbs, apply 1 cup of fertilizer per 10 square feet of garden soil. For potted herbs, mix in ¼ cup of fertilizer per 5 gallons of container capacity.

3. Jobe’s Herb Fertilizer Spikes 4-3-3

Best Fertilizer for Herbs in Pots

3. Jobe's Herb Fertilizer Spikes 4-3-3

Pros

  • No measuring or mixing required
  • Conveniently feed for up to 8 weeks
  • Releases beneficial microbes into the soil

Cons

  • Does not evenly distribute nutrients in the soil

I love seeing new and experienced gardeners try their hands at growing herbs indoors! And Jobe’s fertilizer spikes are a great alternative to messy granular or liquid formulas. I tend to recommend spikes for fertilizing smaller plants and since herbs are in that small plant category – especially when grown indoors – these are just the ticket. 

The relatively even NPK ratio means that they are great for fertilizing herbs, plus are also odor free once inserted beneath the soil. In addition, they also help to improve soil conditions which can become easily depleted in containers and pots.

Not only do they work particularly well on herbs when used correctly, but they’re also a godsend for those of us — I’m certainly guilty of that — who have trouble sticking to a frequent fertilizing schedule. 

How To Use: Push fertilizer spikes into the soil until fully submerged. Avoid placing spikes directly next to plants to prevent root damage. For in-ground and potted herbs, reference the product label for the correct number of spikes to use.

Pros

  • Made with organic ingredients
  • Compatible with handheld sprayers and drip lines

Cons

  • May have a fish-like odor

Neptune’s Harvest is a small fertilizer brand that offers several unique organic formulas for herbs and more. Just don’t let the ingredients scare you!

I recommend this fertilizer for large vegetable and herb gardens because it can be applied with a hose sprayer attachment and the concentrated liquid formula makes it easy to mix to the exact strength your plants need.

The one big downside to this formula is the (unsurprisingly) fishy smell. For that reason, you probably won’t want to use this fertilizer for indoor herbs.

How To Use: Mix up to 1 ounce of fertilizer per gallon of water. Water thoroughly from above until the soil is saturated.

Pros

  • Releases nutrients into the soil for up to 3 weeks
  • Safe for all houseplants
  • Made with organic, vegan ingredients

Cons

  • Low nitrogen content

EarthPods is another brand that offers high-quality slow-release fertilizer capsules for potted herbs. Again, I recommend using these in small indoor containers to get the most bang for your buck.

These capsules are filled with organic ingredients that are safe to use on all indoor plants. So if you have a large houseplant collection, this fertilizer could be a wonderful investment.

While the low N-P-K ratio means there’s little risk of overfeeding, you may find that fast-growing herbs crave a bit more nitrogen than this fertilizer provides.

How To Use: Push fertilizer capsules into the soil around herbs. Check the product label for the recommended number of capsules to use per plant.

Pros

  • Comes in an easy-to-use pump bottle
  • Certified for organic production by OMRI

Cons

  • Does not contain any micronutrients

This Dr. Earth liquid fertilizer is a no-fuss option for all kinds of herbs. It can be applied directly to the soil or diluted in water depending on your preferences.

One important thing to note about this fertilizer is the lack of micronutrients. It only contains nitrogen, phosphorus, and potassium. This isn’t necessarily a bad thing but I recommend keeping an eye out for nutritional deficiencies if you use this on perennial herbs.

How To Use: Apply directly to the soil at a rate of 1 pump per gallon of container capacity. Alternatively, mix 8 pumps per gallon of water. Water from above until the soil is saturated.

Pros

  • Fortified with many micronutrients
  • Slow-release granules feed for 6 months

Cons

  • Highly concentrated formula

Normally I’d to shy away from using a fertilizer with so much nitrogen on delicate garden herbs. But this Osmocote fertilizer offers tons of benefits if you know the right way to use it.

The best thing about this formula — at least in my opinion — is that it feeds for 6 months. It’s perfect for the hands-off gardener who still wants to enjoy yummy veggies and herbs.

To counteract how concentrated this formula is, I recommend applying it at half of the recommended rate. You can always adjust as needed depending on how your herbs respond.

How To Use: Sprinkle ½ scoop of fertilizer on soil per 2 gallons of container capacity. Gently rake into the surface before watering thoroughly.

Pros

  • Releases nutrients for up to 3 months
  • Convenient packaging
  • Can be used on in-ground beds and containers

Cons

  • Too concentrated for some herbs

Miracle-Gro is one of the most recognizable and accessible fertilizer brands for home gardeners. For vegetables and herbs, in particular, I recommend this granular plant food.

Miracle-Gro Shake N’ Feed products are very easy to apply and store. You can use this fertilizer on in-ground garden beds and containers. 

To prevent overfeeding, I suggest applying this fertilizer at a rate of ½ tablespoon per square foot to start. Fast-growing herbs may crave more.

How To Use: Shake granules evenly over the soil, avoiding the plant itself. Gently rake the fertilizer into the surface before watering the soil thoroughly.

How to Fertilize Herb Plants

Granular fertilizers should be applied directly to the soil without touching the plant itself. Work the granules into the top layer of soil with a rake or trowel to prevent run-off. Always water immediately after applying dry fertilizers.

Apply concentrated liquid fertilizer directly to the soil. Fertilizer diluted in water can be used as a foliar feed.

Avoiding Fertilizer Burn

Fertilizer burn is a common ailment caused by too much nitrogen in the soil. It can also occur when fertilizer touches the plant directly and damages leaf or stem tissue. 

The best way to prevent it is to measure all fertilizer applications carefully and stick to a consistent watering schedule.

Fertilizing Indoor Potted Herbs

In general, potted herbs need more frequent feedings than in-ground ones. This is because nutrients are flushed out of the container with each watering. 

If not watered enough, container-grown herbs are also more likely to experience fertilizer burn caused by salt buildup so it is important to water at least twice between feeding your herbs.

Fertilizing Ground-Planted Herbs

In-ground gardens receive some nutrients from the natural soil, so fertilizing is not as crucial as potted herbs. While you may need to apply more fertilizer overall, the time between feedings will be much longer when compared to container-grown herbs.

When to Fertilize Herbs

Nearly all herbs benefit from an application of slow-release fertilizer at the beginning of the growing season. For perennial herbs, be sure to wait until the plant exits winter dormancy before applying any fertilizer.

How Often to Fertilize Herb Plants

Fast-growing herbs may need more than one application of fertilizer per year. Continue fertilizing every 2 to 8 weeks (depending on your chosen formula) throughout the growing season.

Fertilizing Herbs During Winter

Winter fertilizer isn’t necessary for herbs growing outdoors. However, you can continue fertilizing fast-growing herbs grown indoors as long as they are actively growing. Simply apply a liquid feed once a month, or use a fertilizer spike placed near the root ball.

Verdict: Best Fertilizers for Herbs

Choosing the right fertilizer for your herb garden can increase yield and improve flavor. Just be aware of what types of herbs are growing in your garden and how their needs might align with your go-to feeding routine.

Espoma Organic Indoor Plant Food 2-2-2

Best Organic Fertilizer for Herbs

Espoma Organic Indoor Plant Food 2-2-2

A fast-acting liquid concentrate feed. Great for edibles such as herbs because it’s 100% organic and has a perfect NPK ratio.

If you’re interested in using organic fertilizer for your small, container-grown herbs, I suggest using Espoma Organic Indoor Plant Food 2-2-2. A gentle well balanced liquid concentrate that makes feeding less of a chore. 

Dr. Earth Organic 5 Tomato, Vegetable & Herb Fertilizer 4-6-3

Best Fertilizer Granules

Dr. Earth Organic 5 Vegetable & Herb Fertilizer 4-6-3

Organic, slow-release granules that help to improve soil and can be used for a range of garden herbs and vegetables.  

An alternative option is using fertilizer granules such as Dr. Earth Organic 5 Tomato, Vegetable & Herb Fertilizer 4-6-3. It features feed-grade ingredients that can benefit both fast- and slow-growing herbs and offer a slow release of nutrients for up to two months.

Jobe's Herb Fertilizer Spikes 4-3-3

Best Fertilizer for Herbs in Pots

Jobe’s Herb Fertilizer Spikes 4-3-3

Convenient, mess-free fertilizing that has been specifically blended for herbs. Ideal for containers, or indoor grown plants. 

Or, you can dip your toes into the world of fertilizer spikes with Jobe’s Herb Fertilizer Spikes 4-3-3. These offer a relatively even balanced NPK ratio and are ideal for smaller containers or indoor-grown plants.