{"id":8630,"date":"2016-02-14T12:00:15","date_gmt":"2016-02-14T17:00:15","guid":{"rendered":"http:\/\/www.whatgrowsthere.com\/grow\/?p=8630"},"modified":"2016-02-11T13:17:51","modified_gmt":"2016-02-11T18:17:51","slug":"changing-bigleaf-hydrangea-flower-color","status":"publish","type":"post","link":"https:\/\/whatgrowsthere.com\/grow\/2016\/02\/14\/changing-bigleaf-hydrangea-flower-color\/","title":{"rendered":"Changing Bigleaf Hydrangea Flower Color"},"content":{"rendered":"

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\"'Endless<\/a>

‘Endless Summer’ Hydrangea<\/p><\/div>\n

\"Bigleaf<\/a>

Bigleaf Hydrangea at pH 6.4 or higher<\/p><\/div>\n

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Bigleaf hydrangeas (Hydrangea macrophylla<\/em>), aka \u201chortensia” hydrangeas, bear pink flowers in low acidic and alkaline soil and blue flowers in mildly acidic soil. Some tips about regulating soil pH and flower color in bigleaf hydrangeas follows.<\/p>\n

First, a short review about soil pH. Soil pH measures soil acidity\/alkalinity on a scale of 0-14, with 7.0 being neutral. Numbers above 7.0 indicate alkaline soil while numbers\u00a0below 7.0 indicate acidic soil. Bigleaf hydrangeas\u00a0flower blue if the pH is between 5.0 and 6.2. Flowers\u00a0are pink\u00a0if soil pH\u00a0rises to 6.4 and higher.<\/p>\n

Flower color is\u00a0an expression of the amount of aluminum ions (Al+++) in the soil. Aluminum is most available to the plant in\u00a0acidic soil, and less available in alkaline soil. Gardeners typically\u00a0purchase aluminum sulfate to lower soil pH. Unfortunately, aluminum\u00a0toxicity to plants is a big concern because\u00a0hydrangeas need only small amounts of Al+++.<\/p>\n

Garden and shrub beds near cement or concrete foundation walls, sidewalks and driveways, often\u00a0exhibit low acidic or slightly alkaline soil pH. Over\u00a0many years limestone leaches from the cement or\u00a0concrete. While limestone is ideal for most vegetables, flowers or lawn grasses, bigleaf hydrangeas\u00a0will bloom pink instead of blue.<\/p>\n

Pink Flowered Hydrangeas:<\/strong> Gradually add hydrated or dolomitic lime to raise soil pH above 6.2. Be careful on the amount of lime\u00a0that you\u00a0add. Above pH 6.4, the quantity of available iron in the soil may become deficient or unavailable to the plant. The hydrangeas take up aluminum best at lower (more acid) pH levels. By raising soil pH, Al+++ is less available to the plant.<\/p>\n

Blue Flowered Hydrangeas:<\/strong> For bigleaf hydrangea to flower blue, add aluminum sulfate to garden soil or garden container. Distribute even amounts of aluminum sulfate into soil around the drip line of each shrub. Use of pine needle or\u00a0bark mulch aids to keep\u00a0soil slightly more acidic.<\/p>\n

Directions: <\/strong>Apply 1\/2 oz (1 Tbsp) aluminum sulfate per gallon of water be applied to plants monthly. Irrigate plants immediately following application to prevent burning roots.<\/p>\n

Caution:<\/strong> using high amounts of phosphorus fertilizer may result in pink flowered hydrangeas. Soils low in phosphorus and high in potassium bloom more.<\/p>\n","protected":false},"excerpt":{"rendered":"

\u00a0               Bigleaf hydrangeas (Hydrangea macrophylla), aka \u201chortensia” hydrangeas, bear pink flowers in low acidic and alkaline soil and blue flowers in mildly acidic soil. Some tips about regulating soil pH and flower color in bigleaf hydrangeas follows. First, a short review about soil pH. Soil pH measures soil […]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[444,357,398,1304,710,144,665,675,551,202,777,630,706,7,113],"tags":[],"_links":{"self":[{"href":"https:\/\/whatgrowsthere.com\/grow\/wp-json\/wp\/v2\/posts\/8630"}],"collection":[{"href":"https:\/\/whatgrowsthere.com\/grow\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/whatgrowsthere.com\/grow\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/whatgrowsthere.com\/grow\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/whatgrowsthere.com\/grow\/wp-json\/wp\/v2\/comments?post=8630"}],"version-history":[{"count":5,"href":"https:\/\/whatgrowsthere.com\/grow\/wp-json\/wp\/v2\/posts\/8630\/revisions"}],"predecessor-version":[{"id":8640,"href":"https:\/\/whatgrowsthere.com\/grow\/wp-json\/wp\/v2\/posts\/8630\/revisions\/8640"}],"wp:attachment":[{"href":"https:\/\/whatgrowsthere.com\/grow\/wp-json\/wp\/v2\/media?parent=8630"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/whatgrowsthere.com\/grow\/wp-json\/wp\/v2\/categories?post=8630"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/whatgrowsthere.com\/grow\/wp-json\/wp\/v2\/tags?post=8630"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}