Watering schedule
How often to water Sticky Jerusalem Sage (Phlomis viscosa) — the schedule
Also called Sticky Jerusalem sage, Viscous phlomis.
More about sticky jerusalem sage
About Sticky Jerusalem Sage
Phlomis viscosa · also called Sticky Jerusalem sage, Viscous phlomis · flowering
Phlomis viscosa is a robust, glandular-sticky perennial or short-lived sub-shrub native to the eastern Mediterranean, from Israel and Lebanon through Turkey and Cyprus, growing on rocky, dry slopes and garrigue. It produces bold whorls of golden-yellow hooded flowers above large, sticky, rugose leaves that trap dust and insects. The key care rule is excellent drainage — soggy winter soil quickly kills the rootstock. Pet-toxicity status is not confirmed by the ASPCA; treat as mildly toxic out of caution.
Ideal humidity: Low to moderate (30–55% RH)
The watering schedule, season by season
Sticky Jerusalem Sage flowers best on steady, even moisture — let it dry out hard and it drops buds; keep it soggy and the roots rot before it can bloom. The base rhythm for sticky jerusalem sage is once every 2 weeks in summer; suspend watering october–march except in prolonged drought, but the real interval moves with the season, the light and the pot — so treat the figures below as a starting point and always confirm with the plant itself.
- Spring & summer (active growth): Spring and summer (active growth and bloom): keep evenly moist, watering when the top 2-3 cm is dry — typically every 2 weeks.
- Autumn (slowing down): Autumn: ease back as flowering finishes and growth slows; let it dry a little more between waterings.
- Winter (rest / dormancy): Winter / rest: water sparingly while it rests, then resume as new growth and buds appear.
Very drought-tolerant once established; the sticky glandular hairs help reduce water loss, so the plant performs well in exposed, dry positions without supplemental irrigation.
Want this turned into a live reminder that adjusts to your home and the weather? The Growli watering calculator takes your pot size, light and season and returns a starting interval for sticky jerusalem sage in seconds.
How to tell sticky jerusalem sage needs water
A calendar is the worst way to water sticky jerusalem sage. Check the plant and the soil instead — for this species, look for these signals in order:
- The top 2-3 cm of soil is dry to the touch.
- Leaves or flower stems lose turgor and start to droop.
- Buds stall or the pot feels light.
The most reliable single check is the first one on that list. When two signals agree, water; when they disagree, wait a day and look again — under-watering sticky jerusalem sage for a day is almost always safer than over-watering it.
Overwatering vs underwatering sticky jerusalem sage
The two failure modes can look alike at a glance, so check the soil weight and wetness before you decide. For sticky jerusalem sage specifically:
Signs you are overwatering
- Yellowing leaves, bud drop, and a heavy, constantly wet pot.
- Mushy stems or crown rot at soil level.
- Fungus gnats and a sour soil smell.
Signs you are underwatering
- Wilting, bud and flower drop, and crispy leaf edges.
- A faded, stressed look and a rootball that has pulled from the pot sides.
Erratic watering — bone dry then flooded — makes sticky jerusalem sage drop its buds and flowers. Consistency through the budding period is what protects the display.
Water quality notes
Tap water is generally fine for sticky jerusalem sage unless your water is very hard; rainwater is a safe default if leaf tips brown.
Seasonal and environmental adjusters
Every figure above shifts with the conditions in your home. For sticky jerusalem sage, the levers that matter most are:
- A blooming plant in good light drinks faster than a resting one — shorten the interval during flowering.
- Brighter, warmer spots dry the pot faster; check before watering rather than fixing a date.
- Empty the saucer after every water so the roots are never sitting in run-off.
Pot choice is part of this too — work out the right size with the pot size calculator, since a pot that is too big stays wet long enough to rot the roots of sticky jerusalem sage.
Sticky Jerusalem Sage watering — frequently asked questions
How often should I water sticky jerusalem sage?
Water sticky jerusalem sage once every 2 weeks in summer; suspend watering october–march except in prolonged drought. Spring and summer (active growth and bloom): keep evenly moist, watering when the top 2-3 cm is dry — typically every 2 weeks. Winter / rest: water sparingly while it rests, then resume as new growth and buds appear.
How do I know when sticky jerusalem sage needs water?
The top 2-3 cm of soil is dry to the touch. Leaves or flower stems lose turgor and start to droop. Buds stall or the pot feels light. The single most reliable test for sticky jerusalem sage is the first signal on that list — checking the soil or the plant directly always beats watering by the calendar.
What does an overwatered sticky jerusalem sage look like?
Yellowing leaves, bud drop, and a heavy, constantly wet pot. Mushy stems or crown rot at soil level. Fungus gnats and a sour soil smell. Erratic watering — bone dry then flooded — makes sticky jerusalem sage drop its buds and flowers. Consistency through the budding period is what protects the display.
What are the signs of an underwatered sticky jerusalem sage?
Wilting, bud and flower drop, and crispy leaf edges. A faded, stressed look and a rootball that has pulled from the pot sides.
Can I use tap water on sticky jerusalem sage?
Tap water is generally fine for sticky jerusalem sage unless your water is very hard; rainwater is a safe default if leaf tips brown.
Keep reading
- Watering sticky jerusalem sage in the UK — hard vs soft tap water
- Sticky Jerusalem Sage care — the full brief (light, soil, humidity, problems, pet safety)
- Watering calculator — get a starting interval for your exact pot and light
- Pot size calculator — the right pot keeps watering forgiving
- Why is my plant wilting? Wet vs dry diagnosis
- Overwatered plant — signs and how to recover it
- Underwatered plant — signs and how to rehydrate it
- How often to water violet petunia
- How often to water wave purple petunia
- How often to water supertunia bubblegum petunia
- All 10153 watering schedules in the Growli library