Lavender is one of those plants that can send you a world away. Down a country lane in Provence or a quiet, village cafe’ in Tuscany, just by running your fingers through it, just enough for its perfume to be released. 

450 different varieties, worldwide, carry the benefit of not being fussy when it comes to Fertilizer. These plants aren’t heavy feeders. But, there will be times when the best fertilizer for lavender will be needed to supplement any soil deficiencies or adjust the soil pH to ensure proper nutrient absorption. 

Choosing The Best Fertilizer For Lavender 

If you are in rush to seek out the best fertilizer for your lavender, then here are my top picks at a glance.

Best Organic Fertilizer

Down to Earth Tree & Shrub Fertilizer 4-2-4 

100% natural ingredients, suitable for new plantings, and established lavender to encourage flowering. 

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Best Slow-Release Fertilizer

Espoma Organic Garden-tone 3-4-4 

Slow-release granules are the ideal choice for a single application in spring.

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Best Liquid Fertilizer

Superthrive Organic Natural Liquid Fertilizer 4-1-1 

A fast-acting, liquid formula with a high nitrogen ratio, intended for ailing plants and to enhance flower yield.

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Granular Vs Liquid Fertilizer 

The difference between these is simply a matter of what works best for you. Each carries different benefits and risk levels.

Liquids work faster yet need to be applied more frequently. Slow-release granules provide consistent nutrition for several months at a time. With few applications needed. 

Liquid Concentrate 

A water-diluted mixture of concentrated nutrients works through either quick root absorption or as a foliar spray. This can prove a cost-effective choice. A little liquid concentrate goes a long way and water-soluble cakes can be stored, with no mess, until you’re ready to use them. 

Slow-Release Granules 

Granules release nutrients gradually, triggered by warming temperatures. These are then consumed and converted into an easily absorbed form by soil microbes. Making nutrients available in the soil for much longer timeframes. 

This ultimately means less toil when it comes to the application of the fertilizer and more time enjoying your green space for you. Slow-release granules are also far less likely to cause root burn.

Effect of Soil pH on Lavender 

Despite being warm-climate natives, some lavender varieties tolerate cold-winter zones better than others. Each may also have slightly different needs. It’s best to do a soil test to determine present nutrients and current pH levels. These results will help point you toward the right fertilizer. Lavender thrives in a 6.5 to 7.5 pH range. This is important because when soil pH is too low, nutrients are overly absorbed, causing plant damage. Too high and the opposite happens. Nutrients are locked in the soil and unavailable to roots.

Lavender Fertilizer N-P-K 

Choosing a low NPK ratio is key to properly nourishing lavender plants.  What is an NPK ratio? You might ask. Well, every brand displays a three-numbered formula, indicating its proportions of nitrogen, phosphorus, and potassium.

A 4-2-4 NPK has 4% nitrogen, 2% phosphorus and 4% potassium. These low percentages will ensure proper nourishment without risking plant damage.

Best Fertilizer For Lavender Reviews 

Product research and testing take time and money. For your convenience, I’ve done that for you. Comparing a wide range of fertilizers, on several different lavender varieties. 

These are my picks for the top 6 best fertilizers for abundant blooms on lavender plants. 

1. Down to Earth Tree & Shrub Fertilizer 4-2-4

Best Organic Fertilizer

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Pros    

• Effective on all flowering plants and trees.
• Formulated for vigorous growth and abundant flowers.

Cons

• May attract pets and wildlife with the organic smell. 

Fortified with 11 types of mycorrhizal fungi, this is my pick for the best Organic fertilizer. It’s a slow-release formula that is suitable for use both for new, tender plantings and also established lavender shrubs.

Despite this being marketed for trees, I was so pleased to see how quickly new growth had sprouted on my own Spanish lavender. This completely organic and mild NPK facilitated robust foliage, bud development, and new root growth. 

How To Use: For both new and established lavender plants, side dress with the recommended dosage, roughly ¼ cup, each month during the growing season.

2. Espoma Organic Garden-tone 3-4-4 

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Pros    

• High flowering results from an organic product
• Results after just one week

Cons

• An organic odor may be attractive to pets 

These Garden-Tone granules are my next slow-releasing option and work well for lavender grown in nitrogen-rich soil. As is the case for all Espoma products, their Trademark Bio-Tone microbes formula ensures an increased disbursement of nutrients throughout the soil. 

I regularly add aged compost to all my perennial beds, and I was relieved to see that this didn’t overwhelm them or cause the growth of excess foliage vs flowers. In fact, the flowering period of a border of English lavender I used this on lasted much longer than usual.

How To Use: Mix the recommended amount into the soil prior to planting or apply to seedlings 7-10 days after planting. Repeat monthly from May to August.

3. Superthrive Organic Natural Liquid Fertilizer 4-1-1 

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Pros    

• Gentle and non-burning solution
• Reduces transplanting stress

Cons

• May lead to excess foliage in nitrogen-rich soil 

This gentle, pre-mixed liquid solution from Superthrive is formulated to replenish nitrogen deficiencies, in poor soil, that can cause foliage chlorosis (yellowing of leaves) and weakened photosynthesis capabilities in all lavender varieties.

The natural and non-toxic ingredients in this liquid concentrate immediately perked up some struggling Portuguese lavender I worked with. New growth and bud numbers rapidly increased with easier access to vital nitrogen.

How To Use: Add 4tbsp (or 1tsp for new plantings) of SUPERThrive to each gallon of water you apply to your plants, every 2-4 weeks.

4. Espoma Organic Bone Meal 4-12-0

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Pros

• All-natural source of organic phosphorus and nitrogen
• Helps to loosen heavy, clay soil

Cons

• Not recommended for plants that require higher potassium 

Espoma’s organic bone meal will prove highly effective at increasing available phosphorus in your soil. 

The natural phosphorus and nitrogen this provides can’t be beaten for providing flowering plants in less-than-fertile soil with the kind of growing power they need for abundant blooms. Especially if you’re an organic gardener. 

How To Use: Apply 1 or 2 pounds depending upon the size of your ground surface area. Apply 2 oz or one heaping tablespoon per potted plant and work into the soil. 

5. Neptune’s Harvest Fish & Seaweed Fertilizer 2-3-1 

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Pros

• A mix of nutrients from both fish and kelp
• Organic results without harmful chemicals

Cons

• Overfeeding may cause plant burn 

This OMRI-certified, organic fish emulsion and seaweed concentrate provide all the nutrient coverage your lavender plants need for abundant blooming. Plants will also be more fragrant and longer lasting. 

The hydrolyzed formulation means essential oils and proteins are left intact making this suitable for use as an all-purpose fertilizer that will benefit everything in your garden.  

How To Use: Indoor plants – Use 1 tablespoon per gallon of water, every 1-2 weeks. Outdoors –  Use 1/8 Cup (1 fl. oz.) per gallon of water, every 1-2 weeks. 

6. Miracle-Gro Performance Organics Edibles 7-6-9 

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Pros

• Vigorous growth and plant vitality with consistent use
• Increased yield from a focused NPK

Cons

• Not recommended for use as a water-soluble 

Of course, I have to include this new, slow-release, organic option from a brand well-known for its dependability. 

With an endorsement from the OMRI, Miracle-Gro’s biotic formula gave me an increased bloom yield (more typical of inorganics) plus the peace of mind that comes from feeding plants that I’m going to either eat or do projects with. 

How To Use: Shake granules evenly around plants per the recommended amount and water regularly. Then, repeat every 4-6 weeks for continuous feeding. 

How To Fertilize Lavender Step-By-Step 

No matter which hardiness zone you live in, how to fertilize lavender (all varieties included) and how to protect them from the effects of over-fertilization, remain the same. 

The following steps apply to those grown in garden beds, pots and containers and even hanging baskets. 

Fertilizing Lavender in Pots and Containers 

Nutrients leach out of contained soil rather quickly given the more frequent watering that potted plants typically require. 

For most other plants, this can be problematic. But lavender actually prefers low amounts of nutrients. So, there’s no need to increase fertilizing, here.

Over Fertilizing Lavender 

Adding compost and other organic materials to your soil will provide lavender with all the nutrients it needs. Thus, adding fertilizer to already fertile soil may actually kill your plants. 

If applying traditional fertilizers is more your style, keep to a low NPK. Anything higher could damage your plants. 

Achieving Better Lavender Blooms 

The best lavender fertilizer is but one part of a larger effort toward healthy plants. Lavender also needs 6-8 daily hours of full sun and well-draining soil. 

Most importantly, lavender blooms on new growth. Pruning away old growth, in early spring, will stimulate more flowers.

When To Fertilize Lavender 

Because lavender only needs a small number of nutrients in order to thrive, the number of times you apply fertilizer will be low, too. 

When using slow-releasing granules, only one application in spring is needed. Liquid fertilizers will recommend a few more throughout the season. 

How Often To Fertilize Lavender 

If you live in a harsh-winter region, a second granule application, in fall, can increase tolerance against the cold. Yet, liquid options like Neptune’s Harvest and SuperThrive, recommend applications every 2-4 weeks. This is because these work to improve soil fertility as well as nourish plants. 

Verdict: Best Lavender Fertilizers 

The best fertilizer for lavender is those with low ratios. Decide which application method will work best for you such as granules like Down to Earth for Trees and Shrubs or Espoma Organic Garden-tone if you prefer the slow-release option that means you don’t need to re-apply too often. 

Best Organic Fertilizer

Down to Earth Tree & Shrub Fertilizer 4-2-4 

100% natural ingredients, suitable for new plantings, and established lavender to encourage flowering and protect against stresses. 

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Best Slow-Release Fertilizer

Espoma Organic Garden-tone 3-4-4 

Slow-release granules are the ideal choice for providing an ongoing source of nutrients while also improving the soil.

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Or if a zippy fast-acting liquid option is more your gardening style, choose Superthrive Organic or even, Neptune’s harvest. 

No matter which, if used according to manufacturers’ recommendations and if pruned well to remove old growth in order to promote flowering from new growth, you can expect your lavender to be lush, healthy, and fragrant. 

Best Liquid Fertilizer

Superthrive Organic Natural Liquid Fertilizer 4-1-1 

A fast-acting, liquid formula with a high nitrogen ratio, intended for ailing plants and to enhance lavender flower size and yield.

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FAQs Fertilizing Lavender Plants