Lavenders should produce a beautiful bloom, and waft its distinctive aroma throughout your garden every growing season. However Lavenders will only bloom successfully if you have replicated some of the conditions of its natural Mediterranean range.
Lavenders love full sun, sandy soils with medium to low fertility and almost drought like conditions with infrequent watering.
If your Lavender has failed to bloom or has produced relatively few flowers then go through the check list and identify the problem so that you can find out what to do to make your lavender display a spectacular bloom in the next growing season, but don’t worry, growing lavender that blooms is very easy once you have made some adjustments.
The most common reasons for lavenders not blooming…
- The soil is too fertile for lavenders
- Adding fertilizer to the soil
- Not enough sunlight (Lavender needs full sun)
- Wrong soil pH
- Too much water
- Soil drains too slowly
- Over pruning lavender foliage
- Lavender not yet mature
- Wrong lavender for your climate
1. Soil is too Fertile for Lavenders
Lavenders grow in their native Mediterranean range in sandy soils, which are low to medium in terms of fertility in Spain, Italy and France.
It is under these soil conditions that they naturally produce the most flowers and the best fragrance.
If there is an abundance of nutrients in the soil then the lavenders tend to grow more foliage and produce little to no flowers.
Lavenders actually thrive in these seemingly harsh conditions and gardeners often provide them with rich, fertile soils with a high organic content as this is what many popular garden plants love.
Garden soil that is naturally high in fertility is great for growing heavy feeding plants such as roses but it does not replicate the natural growing conditions of lavender and consequently they will not to bloom to their full potential.
What to do about it. The solution is to either plant lavenders in pots or raised beds, or amend the soil that they are currently in.
Lavenders produce the best blooms in the sandy or rocky soils of Italy, France and Spain. Therefore you have to emulate these conditions by adding plenty of sand or grit to the soil they are in.
Sand and grit is naturally low in nutrients so it will counteract the high fertility of rich soils.
You need to amend the soil so that it is 30-50% sand and grit, with the rest of it as soil or well rotted compost (if you are planting in pots.
Amending soil for lavenders is not an exact science and may require some trial and error depending on the specific conditions of your garden, but the more naturally fertile your soil is, the closer to a 50:50 mixture of sand (or grit) to soil you should aim for to counter the effect of high fertility.
The best time of year to transplant or amend the soil for lavenders is late winter or very early spring. This is the period when the lavender is emerging for its winter dormancy and this will minimise transplant shock.
If the lavender is already in the ground then you can gently work the ground with a fork and tease the plant out, making sure all the roots are intact. Try not to use a spade or shovel as this can cut through the roots.
At this point you can remove a significant quantity of fertile soil and redistribute around your garden as mulch. Replace some of the soil with sand or grit (both work well) aiming for at least a third grit to two thirds soil.
Replant the lavender in the amended soil and water back in, giving the soil a good soak. This will help to mitigate any transplant shock and should give your lavender a better chance at blooming in the coming spring and summer months.
2. Adding Fertilizer to Lavenders
Adding fertilizer to lavenders reduces the chance a spectacular purple bloom.
This may seem counter intuitive as many plants in the garden will only produce a strong bloom with the assistance of fertilizer, but lavenders are the exception.
Lavenders actually require relatively low fertility conditions in order to bloom successfully.
Adding fertilizer (much like high nutrient soils) will encourage plenty of foliage growth and very few flowers.
Adding more fertility to the soil is contrary to the lavenders naturally preferred conditions and can even burn the roots.
What to do about it. This one is really easy…don’t use any fertilizer! Let lavenders enjoy their sandy soils and soon enough they will display a spectacular bloom.
Lavenders do not need any mulch or fertilizer from a fertility perspective although its okay to add a wood chip mulch or similar mulches simply for aesthetic purposes or to keep the weeds down.
The fact that lavenders live in low fertility sandy soils means that the conditions are not as favourable for weeds, so there will be less work for you to do in the summer and more time to enjoy your lavenders!
If you have already added fertilizer then try to recover it if possible (if it is in granular form and hasn’t broken down into the soil yet) but if you have used liquid fertilizer you will have to endure a season with sub standard flowering a remember not to use any fertilizer the following year!
The lavender should recover and produce a bloom the following season, as long as the conditions are right and there is plenty of sunshine.
3. Not Enough Sunlight (Lavenders Need at least 6 Hours of Sun)
Lavenders that do not receive enough sunlight is a common cause for a poor bloom.
Lavenders are native to sun drenched countries where they receive full sun all day. Lavenders will not grow at all well in the shade let alone bloom well and require at least 6 hours of direct sunlight per day so make sure you position them in the sunniest location of your garden.
There is a direct correlation with lavenders, that the less sunlight the receive the less they will bloom. If the weather during spring and summer is less then ideal with plenty of overcast days then all lavenders in the area will not produce a good flower display, which is the luck of the draw.
In the long term however, the lavender should be unaffected by just one poor growing season and they should be able to bloom next year if the conditions are right and the sun is shining.
What to do. It is essential that lavenders are in at least (preferably more) 6 hours of sun per day to bloom well.
Make sure you keep any overhanging vegetation or trees branches in check so you don’t deprive your lavenders of light. Alternatively you can transplant your lavender into pots and move them if they are not in a position to receive enough light.
Otherwise you may have to move house for a sunnier garden!
English lavender varieties will grow well in cooler, temperate climates and can tolerate frosts in winter but they will still need lots of sunlight to be able to bloom.
4. The Correct Soil pH for Lavenders
If your lavender is not flowering and shows poor growth in general then it may be stressed due to excessive soil acidity.
Lavender can tolerate mild soil acidity but prefer a soil that is pH neutral (7) or slightly alkaline (up to pH 7.5).
Most garden soils are either pH neutral or slightly alkaline as this is the pH level that most organic matter will be once it is full decayed.
However due to a number of factors garden soil can be too acidic for lavenders to thrive.
What to do. Fortunately it is very easy and inexpensive to test the soil pH of you garden soil. All you need is a soil test from amazon. The soil test kit will give you a nice, uncomplicated reading of your soil pH.
Once you have tested you soil you may be able to rule out soil acidity as a cause of poor blooms.
If the reading is between 6.7 to 7.5 pH for your soil, then you are in the ideal range for lavenders.
If you have found your soil is too acidic (lower then pH 6.7) then you will need to amend you soil with garden lime. You can buy garden lime for your local garden store or online.
Garden lime is simply a soil amendment that will raise the pH of the soil when it is applied, so you can turn acidic soil to alkaline soil.
In my experience it is very easy and safe to use, but you must diligently follow the manufacturers instructions to achieve the desired result. Changing the pH of the soil is a gradual process and may take some time to bring about a lasting change.
If you have established you have acidic soil and the lavender is showing signs of stress then I would transplant the lavender as a matter of urgency to a pot that is once third sand and two thirds multipurpose compost and water it in well (see my guide to watering lavenders in pots for details).
5. Too Much Water for Lavenders to Bloom
Over watering is the most common mistake gardens make when caring for lavenders. The Mediterranean countries where lavenders originate (France, Spain, Italy) have very hot and dry summers with infrequent rainfall.
If lavenders are watered too frequently their soil will be too wet for the roots which will lead to the disease root rot.
Lavenders will show signs of stress such as a wilting appearance and a browning of the foliage if exposed to too much water, which is often interpreted as a sign of under watering and a gardener may compound the problem by increasing the frequency of watering.
The signs of stress from over watering will stop your lavender from blooming in the summer.
What to do.
Lavenders thrive in seemingly harsh, almost drought-like conditions, so to grow lavenders successfully in your garden should only water them once every two weeks during hot weather in the spring and summer months.
If there has been significant rainfall or many over cast days within a two week period, then you should skip watering for another two weeks.
This may seem like neglectful treatment compared to the demands of other plants in your garden but lavenders are drought resistant and their roots enjoy dry, fast draining soil.
Your lavender should recover from over watering after about two weeks of drier conditions. Over watering is a problem that is often in associated with slow draining soils.
6. Soil Drains too Slowly
Lavenders need to grow in soil that has a porous texture and drains freely without retaining water for too long. This is because of lavenders love of dry roots. If their roots are exposed to moist material for any length of time then root rot can occur.
Slow draining soil will cause stress to the lavenders with the same symptoms as over watering (drooping appearance and either a browning or yellowing of the leaves) and this will cause it ultimately not to bloom, or produce a sub standard display of flowers.
Clay soils, heavy compacted soils or soils that are too rich in organic content can all cause water or rainfall to pool and retain too much moisture surrounding the roots of lavender.
With a bit of care you can amend the soil, so that it drains quicker and change its structure so that it is more favourable for lavenders.
What to do. The soil in the Mediterranean home range of lavenders is sandy, with a good structure that allows water to drain relatively quickly and it is porous enough so that roots can grow and establish into the soil with ease (clay or compacted soil can be too slick for roots to establish properly).
If your soil drains slowly or stays damp for a long time then you will need to amend the soil to create the right conditions for lavender.
Lavenders do well with a soil profile that is roughly 30% sand or grit (both work well) to 70% compost. However this ratio may rise to 50:50 if the soil is particularly slow draining or your garden is in an climate that receives a lot of rainfall.
It is best to amend the soil by digging in the sand or grit to the planting area prior to planting. However if your lavenders are already in the ground (or in pots) that is noticeably slow draining then you can lift them out of the soil carefully with a fork and add your sand or grit before replanting.
The best time to do this is late winter or very early spring as this will minimise any transplant shock. The sand and grit will improve the soil texture, increase the drainage and sand is relatively low in fertility which is perfect for lavender as they will not bloom in nutrient dense soils.
Amending the soil to improve drainage is not an exact science and every garden will have its own individual conditions to adhere to. As long as you have a good proportion of sand or grit mixed in and the soil doesn’t feel wet or overly moist and observably drains well, then lavenders will be able to thrive and most importantly produce the best display of flowers.
For more information on the best soil for lavenders, take a look at my article What Soil do Lavenders Like?
7. Over Pruning Lavender Foliage
The golden rule of pruning lavenders is to not cut back into the old wood stems as this will more then likely kill the lavender or heavily impact blooms. If the lavender survives been cut back to the wood then it will not display a good bloom. You should always leave a few inches of soft wood when pruning lavenders.
The best time to prune is in late summer after the flowers have bloomed and a tidy up prune in Spring to stimulate new growth.
What to do.
Pruning lavenders is best explained with a visual guide so check out what to do with this YouTube video.
8. Lavender Not Mature Enough to Fully Bloom
If you have gone down the list and checked all the boxes yet your lavender still has produced a good bloom this year then it is possible it is not fully mature yet.
Lavenders always produce better blooms in their second year of growth and should continue to bloom well for a few more years.
It should be noted that lavender is a relatively short lived plant, with some lavenders hybrids producing blooms for only fours years.
However, thanks to their hardiness and love of minimal conditions, lavenders are very easy to propagate so you can produce a production line of new lavenders to replace any that are past their best.
This video shows exactly what to do to propagate lavender and how easy it is.
What to do. This solution requires no extra effort. Simply, follow the best practices of growing lavender and by the next growing season, if its a good summer with plenty of sun, you will be enjoying the sight and smell of lavender in bloom.
In my experience the second and third years always produce the most exuberant blooms.
Remember there is no need to add fertilizer or enrich the soil, the more you neglect lavender the better, even if it goes against your instincts as a gardener!
9. Wrong Lavender for Your Climate
All lavenders require the same sort of conditions to bloom successfully, with full sun, well draining soil and infrequent watering being essential.
This applies whether the lavender its French, English, Italian, Spanish or any of the various hybrids that have been cultivated for garden centres.
However there is one distinct difference. English lavender (and its varieties) are the only types of lavender that can tolerate frosts. They also fair better in more temperate climates then the French, Spanish and Italian lavenders.
French Spanish and Italian lavenders do far better in arid climates that have mild winters, hence there popularity in California and other arid states that do not typically experience significant winter frosts.
What to do. If you are in a climate that experiences cold winters then ensure you plant English lavenders in your garden.
The importance of well draining soil increases with gardens that experience frost in winter, so water can drain away from the roots and not accumulate in the soil and cause root rot as temperatures fluctuate at the point of frost.
English lavenders still produce spectacular blooms and fragrance despite cool winters whereas continental Europe varieties tend to suffer in the cold and either show signs of stress or even die when the temperature warms up for the growing season.
If you’re garden is in a climate that has mild winters then you have greater choice of lavenders to plant as all varieties should do well and produce a good bloom.
If your garden experiences frosts in the winter it is best to stick with planting English lavenders.
The most important factors for ensuring a good lavender bloom is to place them in full sun, water infrequently and ensure they’re in well drained, low nutrient soil.
Lavenders are very easy to take care of because they actually thrive when they are not subject to overly attentive care.
If you are having trouble with your lavenders, just go through each step like a checklist and ensure all the lavenders needs are being met.
With the right adjustments you can ensure your lavender produces flowers and a strong aroma by the next growing season and for many years to come.