{"id":2575,"date":"2019-07-17T00:01:43","date_gmt":"2019-07-17T07:01:43","guid":{"rendered":"https:\/\/depts.washington.edu\/hortlib\/pal\/pal-question-285\/"},"modified":"2025-10-16T16:53:57","modified_gmt":"2025-10-16T23:53:57","slug":"optimal-ph-for-prunus-lusitanica","status":"publish","type":"pal","link":"https:\/\/depts.washington.edu\/hortlib\/pal\/optimal-ph-for-prunus-lusitanica\/","title":{"rendered":"optimal pH for Prunus lusitanica"},"content":{"rendered":"<p><strong>Some of my <i>Prunus lusitanica<\/i> (Portugal laurel) shrubs are changing the color of the foliage and stems. Normally the leaves should be dark green and the stems are a dark cranberry red. The soil here at the coast is very sandy. I have put composted manure (the type from bags), fertilized them, and added a bit of lime to the soil around the trunk and close to the root zone. I have not seen much of a response. Do you know what is the optimal pH for <i>Prunus lusitanica<\/i>? I am concerned about these shrubs because I just planted them last summer.<\/strong><\/p>\n<p>&nbsp;<\/p>\n<p><i>Prunus lusitanica<\/i> tolerates a wide variety of pH and moisture levels in soils. See California Department of Forestry <a href=\"http:\/\/selectree.calpoly.edu\/tree-detail\/prunus-lusitanica\">SelecTree webpage<\/a> about this plant.<\/p>\n<p>According to the <a href=\"https:\/\/web.archive.org\/web\/20231216113844\/http:\/\/www.paghat.com\/portuguallaurel.html\">webpage<\/a> of a local Seattle garden writer, the leaves do change color slightly, acquiring a bluish tinge in late fall to winter. She also says that <i>Prunus lusitanica<\/i> does not like wet feet.<\/p>\n<p>What colors are the leaves turning? You might consider testing the soil, to make sure things are not out of balance. Here is a link to the Miller Library website&#8217;s links about <a href=\"https:\/\/depts.washington.edu\/hortlib\/resources-info\/links\/\">soil testing.<\/a><\/p>\n<p>Is it possible that the bagged manure was still hot, that is, not fully aged? If so, that could cause problems.<\/p>\n<p>You might also bring in photographs or sample leaves to a Master Gardener Clinic for diagnosis. You can locate a <a href=\"http:\/\/extension.wsu.edu\/locations\/\">Master Gardener Clinic<\/a> within Washington State at this website.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Some of my Prunus lusitanica (Portugal laurel) shrubs are changing the color of the foliage and stems. Normally the leaves should be dark green and the stems are a dark cranberry red. The soil here at the coast is very sandy. I have put composted manure (the type from bags), fertilized them, and added a bit of lime to the soil around the trunk and close to the root zone. I have not seen much of a response. Do you&#8230;<\/p>\n<div><a class=\"more-link\" href=\"https:\/\/depts.washington.edu\/hortlib\/pal\/optimal-ph-for-prunus-lusitanica\/\">Continue reading <span class=\"screen-reader-text\">optimal pH for Prunus lusitanica<\/span><\/a><\/div>\n","protected":false},"author":4,"featured_media":0,"menu_order":0,"template":"","keyword":[520,281,131],"class_list":["post-2575","pal","type-pal","status-publish","hentry","keyword-prunus-lusitanica","keyword-soil-amendments","keyword-soil-testing"],"acf":[],"_links":{"self":[{"href":"https:\/\/depts.washington.edu\/hortlib\/wp-json\/wp\/v2\/pal\/2575"}],"collection":[{"href":"https:\/\/depts.washington.edu\/hortlib\/wp-json\/wp\/v2\/pal"}],"about":[{"href":"https:\/\/depts.washington.edu\/hortlib\/wp-json\/wp\/v2\/types\/pal"}],"author":[{"embeddable":true,"href":"https:\/\/depts.washington.edu\/hortlib\/wp-json\/wp\/v2\/users\/4"}],"wp:attachment":[{"href":"https:\/\/depts.washington.edu\/hortlib\/wp-json\/wp\/v2\/media?parent=2575"}],"wp:term":[{"taxonomy":"keyword","embeddable":true,"href":"https:\/\/depts.washington.edu\/hortlib\/wp-json\/wp\/v2\/keyword?post=2575"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}