Monty Don’s July advice for lavender is simple: water it less, not more. Julian Palphramand of British Garden Centres said the plant can keep sending fragrant flowers for weeks if gardeners use sensible watering and give it a little shade at the peak of the day.
Palphramand also warned that in a July heatwave, the real danger for lavender is overwatering. He said gardeners should give it full sun, really good drainage, and only water it when the soil is genuinely dry, because lavender is built to handle hotter temperatures.
British Garden Centres and LBS Horticulture
Palphramand said to check the soil in the morning and water early or late in a heatwave so the plant can take up moisture before the hottest part of the day. Richard Barker of LBS Horticulture added that mature lavender only needs a deep watering when the soil feels dry a few inches below the surface.
Barker’s rule is the one most gardeners miss. Lavender is sold as a low-maintenance plant, but steady wet soil pushes it toward root rot, weak growth, and fewer flowers. For a summer plant that is supposed to shrug off heat, the mistake is usually too much water sitting around the roots, not too little sun.
Jo McGarry on July feeding
Jo McGarry of Caragh Nurseries said gardeners should avoid feeding lavender in July, especially with standard nitrogen-rich fertilisers. She said lavender grown in nitrogen-rich soil can produce up to 40% fewer blossoms than plants grown in poor, free-draining soil, so lean conditions are often better for blooms.
That means the July routine is narrower than many gardeners expect: water only when the soil has dried, skip the feed, and keep the ground open and fast-draining. Lavender’s Mediterranean habits are the point here; it wants conditions that dry out quickly, not a rich, heavily fed bed that drives leaves more than flowers.
Deadheading after July blooms
Regular deadheading can prolong the flowering period, and it does so by pushing the plant’s energy into more flowers rather than seed production. For gardeners trying to keep lavender going through the heat, that is the quickest maintenance job with the clearest payoff.
The practical takeaway is blunt. If lavender is already established, July is the month to ease back on water, avoid nitrogen-heavy fertiliser, and cut off spent blooms so the plant keeps blooming instead of winding down.
