You should water lavender plants about one gallon per plant weekly during the first growing season. Utah State Extension recommends this amount while roots establish. Once your lavender settles in, cut back to half a gallon every two weeks or less. Less water leads to healthier, longer lived plants.
I killed my first lavender plants by watering too much. They got the same treatment as my tomatoes and peppers. The lavender turned gray and died while everything else thrived. Now I barely touch the watering can near my lavender. This hands off approach works much better for these drought loving plants.
Your lavender watering schedule should match the plant's origins. Lavender evolved in dry rocky hills around the Med coast. Summer droughts are normal there. The plant stores water in its stems and gray leaves to survive long dry spells. When you water like a typical garden plant, you fight millions of years of adaptation.
Check the soil before you water, not the calendar. Push your finger about two inches (5 cm) deep into the soil near your plant. If it feels dry all the way down, you can water. If it feels damp at all, wait a few more days and check again. This simple test prevents most overwatering deaths.
How often water lavender depends on your weather and soil type. Sandy soil dries fast and may need water every week in hot summers. Clay soil holds moisture longer and needs water less often. A mulch of gravel helps either soil type drain better. Adjust your schedule based on what you feel when you check the soil.
Container lavender needs more frequent watering than plants in the ground. Pots dry out faster, especially terracotta ones in full sun. Check your potted lavender every few days during hot weather. Water when the top inch feels dry. But make sure excess water drains out the bottom so roots don't sit in moisture.
New plants need more attention than established ones. Water right after planting to help roots settle into the soil. Then water lavender plants weekly for the first growing season while roots spread out. After that first year, your lavender should handle most conditions on its own. Cut back to watering only during extended dry spells.
The lavender water requirements change through the seasons. Spring growth needs a bit more water as new shoots appear. Summer can be dry unless heat waves last more than two weeks. Fall watering should taper off as growth slows down. Winter plants in the ground need almost no extra water at all.
Signs of overwatering show up before root rot kills your plant. Watch for droopy leaves that look wilted even though soil is damp. Gray color spreading from the bottom signals trouble too. Yellow lower leaves often mean wet roots. Stop watering right away if you see these warning signs.
In my experience, most gardeners water lavender two to three times too often. The plant looks thirsty so you grab the hose. But what looks like thirst is often just the natural droop of a hot afternoon. Wait until morning before you decide to water. Healthy lavender perks up on its own when temps cool down.
Morning watering works best if your plant does need a drink. The water soaks in before the heat of the day arrives. Wet leaves dry fast so fungal problems stay away. Avoid evening watering that leaves foliage damp through the night. A simple change in timing prevents many common lavender problems.
Trust your lavender to tell you when it needs water. A slight wilt in afternoon heat is normal and nothing to worry about. But wilting that lasts into the cool morning hours means your plant needs a drink. Learn to read these signals and you will water just the right amount every time.
Read the full article: Growing Lavender: Expert Plan
