Due to their adaptation to surviving in sandy, rather low fertility soils in the Mediterranean region of Europe, lavender plants do not require supplementary feeding or fertilization. The lavender will produce fewer blooms, less smell, and a lanky, untidy appearance if fertilizer is added.
In nutrient-poor, sandy soils that mimic their natural environment, lavenders will yield the most oil, aroma, flowers, and other products, as well as the best-looking plants.
Adding fertilizer will result in an unhealthy plant that may turn yellow or droop in appearance, which is against lavender’s intended lower to medium fertility levels.
In opposition of your intentions, fertilizer ph and too-moisturized organic matter lead to worse flowers.
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Why you Shouldn’t Add Fertilizer to Lavenders
Although they can withstand mild acidity, they prefer to live in rocky or sandy soils that are somewhat alkaline. Lavenders may grow in soils with a pH of 6.5 to 7.5.
Although they have little to no nutritional value, sand and gravel offer the best soil structure for lavender plants. Lavenders need soils with good drainage and low water retention. Lavenders struggle to grow in compacted soil, so the sandy, open, porous texture helps the roots take hold properly.
When modifying soil for lavender planting, a blend of around 30% sand and 70% compost will provide the proper drainage and a small quantity of nutrients. Lavenders will obtain all the nutrients they require from organic material that is already in the soil. (For further information on modifying soil, see my article on transplanting lavenders.)
If you fertilize lavender plants with nitrogen-based fertilizer, the plant’s foliage will turn yellow and take on a lanky, messy appearance. (For advice on what to do if this has occurred to your lavender, check my guide.) Sometimes nitrogen can cause the roots of the lavender plant to burn, ultimately killing the entire plant.
Less is more in terms of fertilizer and watering is the key to growing lavender successfully. Growing lavender can be very little maintenance as long as the conditions are suitable.
The quality of lavender blossoms and the potency of the smell will be significantly more positively impacted by following the proper watering procedures and placing your lavender in the sunniest area in your garden (preferably more than 6 hours of sun each day) than by the fertility of the soil.
It’s more important to mimic the Mediterranean environment where lavender grows successfully, therefore a low- to medium-fertility soil without additional fertilizer will produce better results.
Balancing Fertile Soils for Lavenders
To get the most out of your lavender plants, avoid using garden soils that are heavy in organic matter or clay because they tend to be overly nutrient- and water-retentive.
The purpose of growing lavender is to produce blooms, thus having too many nutrients in the soil would encourage foliage growth at the expense of that.
You can modify the soil with sand or gravel to lower the fertility if you’ve already added fertilizer or have naturally rich soil.
Sand or gravel should be incorporated into the soil to a depth of 18 inches and a breadth of 12 inches in order to accommodate a lavender plant’s mature root system.
To ensure the optimal soil structure and level of fertility, try to strive for a 30% sand to 70% compost mix.
In order to keep the soil sufficiently porous so that the roots may take root, it is usually preferable to supplement clay soil with gravel rather than sand. (For further details, see my post Growing Lavender in Clay Soils.)
Transferring the lavenders into pots is an alternative if changing the soil is difficult.
Because they can give optimal drainage conditions and you can add your compost/sand combination more precisely without having to perform the labor-intensive chore of digging down into soil, lavenders grow very well in pots.
If the lavender is not a cold hardy type, potted lavenders can also be taken indoors to be protected from winter frost (English lavenders will survive cold winters, whereas Spanish, Italian and French lavenders need mild winters and cannot tolerate frosts).
It is better to have too much sand or gravel than not enough because both are crucial for ensuring proper drainage and balancing fertile soils. Lavender will not survive in overly fertile or saturated soils; rather, they will flourish on less fertile, well-draining soils.
Should I Apply Mulch to Lavenders?
Mulch can break down slowly and release nutrients over time, unlike a quick-acting liquid fertilizer, which would overwhelm the roots of the lavender plant. This makes it a wonderful option to add nutrients to the soil.
You will need to exercise caution for two reasons, though:
- Applying an excessive amount of organic mulch, such as compost, leaf mold, or manure, could make lavender plants more susceptible to the fungus that causes root rot. In order to maintain good health, lavender plants require intervals of dryness between waterings. Water can be retained and stored by organic material for a long time. The propensity of the lavender roots to developing root rot will dramatically rise if they are exposed to this constant wetness.
- Mulch with a high nitrogen content, such manure, encourages the growth of foliage at the expense of blossoms, giving the plant a droopy aspect or yellowing leaves. Lavenders prefer alkaline soils, whereas manure can be somewhat acidic.
Growing lavender requires a balance between organic matter and sand or grit to offer some nutrients as well as the structure and lower to medium fertility levels that lavenders require to create blossoms.
The easiest approach to achieve this balance is to add around 70% well-rotted compost and 30% sand to the soil before planting the lavender. If you already planted your lavender, you can remove the plant with a fork and improve the soil before replanting.
A mulch made of wood chips or bark can contribute nutrients to the soil as it decomposes, assist control weed growth, and maintain a healthy soil structure.
Applying a layer of white stone (preferably lime stone) around the growing space is a wonderful substitute and organic mulch for lavenders.
In order to promote flowers and oil production, commercial lavender producers scatter white colored stone around their plants. This will reflect light back onto the plant. The additional benefit of lime stone is that it keeps the soil’s alkalinity high, which protects lavender plants against acidic conditions.
- Lavenders don’t require additional fertilizer because too much nitrogen would turn the plant yellow, result in fewer flowers, and make it appear lanky.
- The sandy, low- to medium-fertility soil conditions of the Mediterranean region of Europe are ideal for lavender cultivation.
- When gardeners mimic the arid soil conditions of their original habitat, lavenders bloom at their finest.
- Before planting lavenders, amend the soil with sand and gravel to help balance out rich, fertile soils and make them more conducive to producing lavender.
- The ideal mulch components are lime stone or wood bark. Over time, wood bark reduces weed growth and gradually improves the soil’s natural fertility. In addition to maintaining the ideal soil pH, limestone will reflect sunlight back onto the lavender, promoting blossoms and aroma.
How do you increase lavender growth?
Plant lavender in full sun, in sandy soil, then cut it in the spring to encourage new growth that will sustain more blossoms. Lavender plants can become stressed from excessive watering and fertilizer application, which results in fewer blooms.
Is Miracle Grow good for lavender?
It’s also crucial to routinely feed lavender with a quality plant food like Miracle-Gro® Performance Organics® Blooms Plant Nutrition for the greatest results—think lots of lovely, fragrant blooms.
What fertilizer is best for lavender?
The ideal fertilizer for lavender is a low nitrogen one designed to promote blooming, but general-purpose fertilizer will also work if diluted. Only fertilizing with a 7-9-5 or 15-15-15 fertilizer in the spring and summer, according to Logee’s Plants, is advised.
When should I fertilize lavender?