Lavenders are drought resistant plants that thrive in hot and dry countries that boarder the Mediterranean such as Italy France and Spain, therefore they are well suited to hot weather.
How to water lavender in hot weather in your garden can vary depending on the climate, amount of rainfall, humidity and whether the lavenders are planted in pots, containers, raised beds or garden boarders.
It is important to remember that lavenders are heat tolerant and there is always more risk from over watering lavender then under watering as their roots prefer sandy soil that dries out between bouts of watering to stay healthy:
|Conditions||Watering Lavender in Hot Weather|
|Established Lavender:||Water Established lavender once every 2 weeks during hot weather with a generous soak if there has been no rainfall.|
|Lavenders in Pots and Containers:||Water every two weeks with a generous soak. Ensure the lavender is in a pot 12-16 inches across or the soil can dry too quickly in hot weather.|
|Cool Temperate climates (such as the UK or Washington and Oregon):||Water once every two or three weeks with a generous soak each time.|
|Hot, arid climates (such as Southern Europe or Southern California):||Water every two weeks with a generous soak.|
|Humid climates/ Hot and Humid Weather||Do not water established outdoor lavenders if the weather is humid as this will increase the risk of root rot.|
|Newly Planted lavender:||Water generously after planting and water once every 3 days for the first 2 weeks. Water once a week for the first month and keep watering once per week if the hot weather persists. When the weather cools water once every two weeks.|
Keep reading to learn exactly how to water lavender in hot weather that are in to different conditions and climates…
How Much and How Often? Watering Lavender in Hot Weather
Lavenders are native to the hot, and dry climate of Mediterranean coastal countries where average summer temperatures are comparable to Southern California.
Therefore lavenders are well suited to growing in hot weather with little rainfall and actually thrive in these conditions, producing the most blooms and strongest aromas in the hottest summers.
- Established lavenders often do not require any additional water during hot weather, particularly if there has been rainfall within the last two or three weeks.
- However if there has been no rainfall for more then two weeks and there is has been consistent, blazing sunshine then give the lavender a generous soak.
Watering lavenders generously promotes the roots to grow further into the soil rather then a little and often approach to watering which encourages the roots to grow shallow and stresses the plant.
Do not water established lavender more frequently then once every two weeks as lavenders are adapted to living in well draining sandy soils and actually prefer the soil to dry out between bouts of watering.
Watering too frequently will likely cause root rot. The symptoms of root rot are drooping foliage (for the solutions read my article why is my lavender drooping?), which is often mistaken for a plant that requires more water.
Avoid root rot by planting lavenders in the appropriate well draining soil mix and watering only every two weeks during hot weather.
(Read my article to learn how to amend soil: the optimal soil mix for lavenders).
Watering in Hot, Humid Weather
If the weather has been hot and humid then the lavender won’t require watering. Lavenders tend to struggle in humid climates as they are adapted to an life of breezy coastal conditions in the South of Europe.
Humidity tends to promote fungal disease in lavenders, particularly root rot.
Additional watering during humid weather will promote the conditions that encourage disease and so should be avoided.
If your lavender is in a pot then move the lavender to an area of your garden that receives the most airflow, rather then stuck on a enclosed patio where there is less of a consistent breeze.
Lavenders are drought resistant and heat tolerant so you do not have to worry about under watering your lavender if the weather is humid, despite the hot weather. The lavender will attain all the moisture it require from the surrounding environment.
For climates that are consistently humid, choose lavender ‘Phenomenal‘ which is a hybrid lavender species that can reportedly cope with humidity better then other lavenders.
In Pots and Containers
Lavenders of all varities grow very well in pots due to the favourable drainage conditions and the increase chance of airflow around the foliage which lessens the chance of fungal disease affecting the lavender.
However lavenders in pots and containers require watering more frequently in hot weather then lavender planted in garden soil.
Garden soil typically retains moisture for longer then pots. I would recommend watering a potted lavender once every two weeks during spells of hot weather with a generous soak, so that water trickles out the bottom of the pot (always plant lavenders in pots with drainage holes in the base).
Do not be tempted to water more frequently then once every two weeks as lavenders thrive on relatively neglectful treatment and the lavender is at greater risk of over watering rather then under watering.
There are two main factors which affect watering your potted lavenders in hot weather. These are:
- The size of the pot or container
- The material of the pot or container
It is important to plant lavenders in pots that are 12-16 inches across, even if it is a smaller variety of lavender (such as as lavender ‘Hidcote’ or lavender ‘Anouk’).
This is because a pot or container of this size has the capacity to contain enough soil so that the lavender roots have enough space to grow and establish in the soil and so that the soil contains enough nutrients and moisture.
Lavenders do prefer a well draining soil mix, amended with sand or grit, however if the pot is too small the roots will not have the opportunity to draw up any moisture before it drains away.
Pots that are too small also heat up much quicker in the sun which increase soil evaporation to the point the lavender has less time to access that water it requires.
Metal and plastic pots conduct heat more readily then, clay or terracotta style pots.
If the pot is predisposed to heating up quickly in hot weather then this will heat up the soil and increase the rate of evaporation so that the lavender roots cannot draw up moisture after watering.
If you plant lavenders in the appropriate pots or containers (12-16 inches across and made from terracotta, clay or ceramics) then watering the lavender once every two weeks in hot weather will ensure the roots have the optimal balance of water, so that the plant stays healthy and the soil has a chance to dry out so the roots are not at risk of fungal disease.
(Read my article choosing the best pot for lavenders).
Watering Lavender in Hot weather After Planting
Lavenders are drought resistant plants that thrive on neglect once established in the soil.
However the only time they tend to be vulnerable to under watering is after they have been planted or transplanted, particularly in hot weather.
The best time to plant lavender is in the Fall or early Spring so that the roots can establish with having to contend with overly hot weather which dries out the soil.
Lavenders require a well draining soil mix that emulates the sandy soils of their native range in order to avoid root rot.
The key to watering lavenders after planting when the weather is hot is finding the right balance of moisture so that the roots have a chance to draw up water as the roots establish in their new soil without drowning them.
Watering newly planted lavenders everyday in hot weather will not ensure the plant lives as soil that is consistently moist around the roots will cause root rot and the plant will not live.
Instead, water the plant generously after planting with a good soak. Water again in two or three days time with another good soak and then water every three days for the first two weeks.
After two weeks scale back the watering of the lavender to once per week for the first month after planting. After once month water your lavender once every two weeks for the rest of the Summer/Fall.
Read my article, how to propagate lavender from cuttings.
- Lavenders are drought resistant plants and thrive in hot and dry weather.
- Established lavender only require watering once per week in hot weather with a generous soak, if there has been no significant rainfall.
- Water lavenders in pots and containers once every two weeks. Plant lavenders in the appropriate sized pot as small pots dry out much quicker in hot weather and try to avoid metal or plastic pots or containers.
- Avoid watering if the weather is humid as additional water will increase the risk of root rot which can kill the lavender.
- It is better to plant lavender in the Fall or Spring so that it does not have to establish during hot weather. Water newly planted lavender more frequently until the roots become established in the soil.