WateringTimesWatering plan, $19
Thalictrum aquilegiifolium, WUCOLS IV

How often to water purple meadow rue in California

In July on the north-central coast, established purple meadow rue in loam needs a deep watering about every 6 days: about 1.5 gallons each time for a plant 2 feet across, about 1.8 gallons a week. Purple meadow rue is a herbaceous perennial with lacy, blue-green leaves like a columbine's. Fluffy clusters of pink, lavender or white flowers stand high above them in spring and early summer, on clumps 2 to 3 feet tall. It wants rich, organic, well-drained soil that stays moist, and shade in the hottest part of the day.

PerennialRated for 3 of 6 zones

How often to water purple meadow rue, month by month

Your city
Plant width
2 ft
Your soil

Type your city above and the days between waterings and the gallons appear here, worked out from your city's climate table. Or read the figures by climate zone further down.

Every month, on your water days. The personal plan prints this for purple meadow rue and the rest of your yard, on the days your water supplier allows.Get the plan for $19

How this is worked out: established roots fill the top 1 foot of soil, and you water again when that soil has dried halfway. Loam soil holds about 1.5 inches of water per foot. Water the whole area the plant covers, and skip a watering after a good soaking rain.

Which soil do you have?

Dig down a few inches, take a handful of moist soil and squeeze it.

  • Sandy: gritty, falls apart when you open your hand, will not form a ball.
  • Loam: forms a soft ball that crumbles when you poke it.
  • Clay: forms a firm, sticky ball and squeezes out into a ribbon between thumb and finger.

Still not sure? Pick loam. Most garden beds sit between sand and clay.

How to measure plant width

A shrub with its width marked from one side to the other and the circle under it shaded blue

Measure across the plant, from the tips of the leaves on one side to the tips on the other.

Water the whole area the plant covers, shown in blue. The gallons here cover that area.

A wider plant means more gallons each watering, not more waterings. While it is young, measure again each spring.

How to tell it needs water

  • Soil dry an inch or two down beside the clump in spring or summer signals purple meadow rue needs water
  • Lacy leaves wilting at midday and staying limp into evening can indicate thirst
  • Leaf edges browning and crisping in afternoon sun can follow a dry root zone
  • Yellowing lower leaves with soggy, airless soil point to poor drainage

How to water it

  • Water around the clump with drip or a soaker so the fine leaves stay dry
  • Soak about 8 inches down and water again as the top inch dries
  • Plant in rich, organic soil with dappled shade in the afternoon
  • Mulch with compost to keep the soil cool and evenly moist
  • Divide crowded clumps in spring and water divisions well

Through the seasons

Keep a new plant evenly moist while it establishes. Established clumps want steady moisture from spring growth through flowering and seed set. It is herbaceous, dying back in winter and returning in spring. Hot afternoons are hard on it, so shade and mulch matter most in summer. WUCOLS rates purple meadow rue high water on the north-central coast. The south coast and South Inland carry a moderate water rating for it. WUCOLS has not evaluated it for the Central Valley, the high desert or the low desert.

In pots

Purple meadow rue grows well in a large pot of rich, moisture-holding mix set in afternoon shade. Check the mix daily in warm weather and water when the top inch is dry. Water until it drains, then empty the saucer. Leave the seed heads for fall interest if you like. In winter, the plant dies back, so water only enough to keep the mix from drying out.

1 Your climate zone six WUCOLS zones, each from its own reference city
Not ratedWUCOLS does not rate Purple Meadow Rue for the Central Valley zone
A year
no figure
Reference
Sacramento climate table
Counts
Plant need, before sprinkler losses

WUCOLS lists Purple Meadow Rue as not evaluated for the Central Valley zone, so no monthly figure is computed here.

Monthly water need by climate zone

Purple Meadow Rue: gallons per square foot per month, by WUCOLS climate zone

MonthN. CoastC. ValleyS. CoastS. InlandHi DesertLo Desert
Jan0.6–0.780.78––
Feb0.84–0.810.87––
Mar1.39–1.151.3––
Apr1.88–1.41.61––
May2.33–1.611.95––
Jun2.58–1.742.29––
Jul2.58–1.982.51––
Aug2.38–1.862.33––
Sep1.98–1.491.86––
Oct1.39–1.151.33––
Nov0.74–0.840.9––
Dec0.5–0.650.68––
Year19.2–15.518.41––

How this is worked out: the WUCOLS water rating for each zone times that zone’s climate for the month. A dash means WUCOLS does not rate the plant there. The figures are what the plant uses, before sprinkler losses.

Plants with the same water needs 16

Rated not evaluated in the Central Valley, like purple meadow rue. Plants that drink alike can share one valve and one schedule.

Lilyleaf LadybellsAdenophora liliifolianot rated, Central Valleyno Central Valley ratingArnicaArnica montananot rated, Central Valleyno Central Valley ratingFrilly BergeniaBergenia ciliatanot rated, Central Valleyno Central Valley ratingCabbage on a StickBrighamia insignisnot rated, Central Valleyno Central Valley ratingBasket PlantCallisia fragransnot rated, Central Valleyno Central Valley ratingForest SedgeCarex sylvaticanot rated, Central Valleyno Central Valley ratingUmbrella DracaenaDianella ensifolianot rated, Central Valleyno Central Valley ratingRusty FoxgloveDigitalis ferrugineanot rated, Central Valleyno Central Valley ratingBig-Flowered FoxgloveDigitalis grandifloranot rated, Central Valleyno Central Valley ratingWoolly FoxgloveDigitalis lanatanot rated, Central Valleyno Central Valley ratingSunset FoxgloveDigitalis obscuranot rated, Central Valleyno Central Valley ratingMale FernDryopteris filix-masnot rated, Central Valleyno Central Valley ratingAlpine Sea HollyEryngium alpinumnot rated, Central Valleyno Central Valley ratingPurple SpurgeEuphorbia dulcisnot rated, Central Valleyno Central Valley ratingQueen of the MeadowFilipendula ulmarianot rated, Central Valleyno Central Valley ratingDropwortFilipendula vulgaris (Filipendula hexapetala)not rated, Central Valleyno Central Valley rating
Minutes for your sprinklers

Turn this into minutes on your water days

Every city page has a calculator that takes purple meadow rue, your sprinkler type and the month, and gives the minutes per water day for that supplier's schedule. Or put it in a zone of the personal watering plan and get all twelve months printed.

Questions people ask

How often should I water purple meadow rue in summer?

In July, established purple meadow rue in loam needs a deep watering about every 7 days on the south coast and about every 6 days in the South Inland zone. Sandy soil holds less water, so waterings come closer together. Clay stretches them. Check the soil before each watering and skip one after a soaking rain.

How much water does purple meadow rue need per day?

In July on the north-central coast, established purple meadow rue needs about 0.3 gallons a day for a plant 2 feet across and about 1.0 gallons a day for a plant 4 feet across. Give it in deep waterings spread days apart rather than a little every day, so the whole root zone gets wet.

Does watering for purple meadow rue change across California?

Yes. WUCOLS rates purple meadow rue separately for each of the six California climate zones: high water in the North-Central Coastal zone, not evaluated in the Central Valley zone, moderate water in the South Coastal zone, moderate water in the South Inland zone, not evaluated in the High and Intermediate Desert zone, not evaluated in the Low Desert zone. The monthly table above shows how the same rating translates into different gallon amounts as reference evapotranspiration changes.

Is purple meadow rue the same as columbine?

No, but its lacy leaves look like columbine or maidenhair fern. The flowers are fluffy clusters rather than spurred cups. It belongs to the buttercup family.

Can purple meadow rue take full sun?

It grows in full sun to part shade but prefers dappled shade in the afternoon. In hot inland summers, afternoon sun scorches the leaves. Keep the soil moist in sunnier spots.

What happens after purple meadow rue flowers?

Clusters of winged seeds follow and stay ornamental into fall. You can leave them for interest. Seeds sown fresh in fall will sprout.

Is purple meadow rue deer resistant?

Yes, it is deer and rabbit resistant. Damage is more often from heat or dry soil. Check moisture first.

When should I divide purple meadow rue?

Divide it as new growth appears in spring. Replant divisions in rich soil and water well. They settle quickly with steady moisture.

More plant watering guides

Hardy CyclamenFine-Leafed MalleeCandelillaMoroccan MoundSeguier's SpurgeGreat Blanket FlowerOsoberryPersian Witch Hazel

Sources