The scorching temperatures we’ve seen this summer have been tough on our gardens, with even the most drought-resistant plants struggling with the extreme heat. While lavender is one of the best drought-tolerant plants you can add to your outdoor space, it’s not invincible - and garden experts have revealed two reasons why yours may have gone brown during the July heatwave.
Many gardeners will have a vested interest in growing lavender. This stunning Mediterranean-garden staple will make your patio smell gorgeous, deter pests and attract pollinators, all while withstanding hot, drought conditions.
But if you’ve noticed your lavender plant has been turning brown during the July heatwave, don’t panic. This is why it could be happening.
1. Heat stress
Even the best drought-tolerant plants can succumb to heat stress, especially when you consider that parts of the UK have reached the high thirties this summer.
‘Potted lavender plants may struggle in hot weather and turn brown due to heat stress on the roots. This happens because the plant can be too hot if potted in a dark container or left in direct sunlight all day, causing the roots to turn brown or die off,’ says Richard Barker, horticultural expert and commercial director of LBS Horticulture.
‘For potted lavender plants that you think are suffering from heat stress, repot them into a lighter coloured container or move them into a spot where they will have shade from the intense afternoon sun.’
2. Overwatering
On the flipside, your lavender might be turning brown because you’ve watered it too much. In a heatwave, it can be tempting to offer plenty of water to your plants to keep them hydrated. But lavender doesn't like this.
‘The reason your Lavender plants are turning brown in hot weather could be because their roots could be overly wet, due to overwatering or poor-drainage soil, which causes root rot. Established lavender plants are highly drought-tolerant and require very little watering. Overwatering is one of the most common reasons lavender fails. Other causes include the drying of spent flower spikes or the plant turning woody from a lack of post-bloom pruning,’ says Olly Peabody, CEO at Envii.
If you think your lavender is turning brown because of overwatering, Richard advises letting it dry out.
‘If you think that your lavender plants in the ground have been overwatered and have root rot, reduce how often you are watering the plant and allow the soil to dry out before watering again,’ he says.
If you're plants are suffering from heat stress, shade netting is a great way to protect them from the heat.
You should also try using lighter coloured plant pots as this absorbs less heat than darker-coloured pots.
‘It can be normal for lavender to turn brown in a heatwave, as this is the plant's way of conserving energy. However, you need to monitor your plant to check that entire sections are not turning crispy or rotting, as this can indicate a larger issue,’ adds Richard.
You don’t need to worry too much if your lavender is turning brown. By identifying the cause, you’ll be able to solve the problem.
