{"id":551,"date":"2026-10-09T00:28:40","date_gmt":"2026-10-08T22:28:40","guid":{"rendered":"http:\/\/192.168.60.121\/en\/substrate-and-drainage\/"},"modified":"2026-10-14T18:37:56","modified_gmt":"2026-10-14T16:37:56","slug":"substrate-and-drainage","status":"publish","type":"post","link":"https:\/\/ortoinbalcone.com\/en\/substrate-and-drainage\/","title":{"rendered":"Substrate and drainage: what to put in the pot"},"content":{"rendered":"<p>Substrate and drainage are the base of every container: the substrate is not &#8220;soil&#8221;, it&#8217;s a mix built to hold water and nutrients while still letting the roots breathe. The reference density used by the site&#8217;s tools is about <strong>0.75 kg per litre<\/strong>, a value that balances weight, aeration and water capacity.<\/p>\n<figure class=\"wp-block-image oib-infographic\" data-oib-fig=\"g5-substrato\" style=\"margin:0 0 2.25rem;\"><img decoding=\"async\" src=\"\/wp-content\/uploads\/2026\/10\/g5-substrato.jpg\" alt=\"Substrato e drenaggio in vaso \u2014 Pot substrate and drainage\" width=\"1672\" height=\"941\" loading=\"lazy\"><\/figure>\n<h2>The structure of a good pot substrate<\/h2>\n<ul>\n<li><strong>Structural organic component<\/strong> (mature compost, preferably peat-free): holds nutrients and water, the basis of substrate and drainage in every pot.<\/li>\n<li><strong>Drainage component<\/strong> (coarse sand, perlite, clay pebbles): about 20\u201330%, lets excess water pass and aerates the roots.<\/li>\n<li><strong>A drainage base<\/strong>: a bed of clay pebbles or sand at the bottom of the pot, and the holes always clear.<\/li>\n<\/ul>\n<h2>The rules of substrate and drainage<\/h2>\n<ul>\n<li><strong>Mandatory drainage.<\/strong> For all 120 plants in the dataset, drainage holes are required. A pot without holes is a recipe for rot.<\/li>\n<li><strong>No waterlogging.<\/strong> After watering, excess water should flow out; if the saucer stays full, empty it.<\/li>\n<li><strong>Repot when needed.<\/strong> When the roots fill the pot and water drains straight through, it&#8217;s time for a bigger pot or a substrate refresh.<\/li>\n<\/ul>\n<p>The <a href=\"\/en\/tools\/\">Substrate and drainage<\/a> tool helps calculate the mix based on the plant and the pot volume.<\/p>\n<h2>Sources<\/h2>\n<ul>\n<li><a href=\"https:\/\/powo.science.kew.org\/\" rel=\"noopener\" target=\"_blank\">Royal Botanic Gardens, Kew \u2014 Plants of the World Online<\/a> \u2014 taxonomy<\/li>\n<li><a href=\"https:\/\/www.rhs.org.uk\/\" rel=\"noopener\" target=\"_blank\">Royal Horticultural Society<\/a> \u2014 plant care<\/li>\n<li><a href=\"https:\/\/extension.umd.edu\/\" rel=\"noopener\" target=\"_blank\">University of Maryland Extension<\/a> \u2014 container growing<\/li>\n<li><a href=\"https:\/\/extension.umn.edu\/\" rel=\"noopener\" target=\"_blank\">University of Minnesota Extension<\/a> \u2014 container + climate<\/li>\n<li><a href=\"https:\/\/extension.psu.edu\/\" rel=\"noopener\" target=\"_blank\">Penn State Extension<\/a> \u2014 urban container growing<\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"<p>Substrate and drainage are the base of every container: the substrate is not &#8220;soil&#8221;, it&#8217;s a mix built to hold water and nutrients while still letting the roots breathe. The reference density used by the site&#8217;s tools is about 0.75 kg per litre, a value that balances weight, aeration and water capacity. The structure of [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":847,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_locale":"en_GB","_original_post":"550","oib_translation_group_id":"","oib_affiliate_link_limit":0,"footnotes":""},"categories":[2],"tags":[11],"class_list":["post-551","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-guide","tag-guide","en-GB"],"_links":{"self":[{"href":"https:\/\/ortoinbalcone.com\/wp-json\/wp\/v2\/posts\/551","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/ortoinbalcone.com\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/ortoinbalcone.com\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/ortoinbalcone.com\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/ortoinbalcone.com\/wp-json\/wp\/v2\/comments?post=551"}],"version-history":[{"count":0,"href":"https:\/\/ortoinbalcone.com\/wp-json\/wp\/v2\/posts\/551\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/ortoinbalcone.com\/wp-json\/wp\/v2\/media\/847"}],"wp:attachment":[{"href":"https:\/\/ortoinbalcone.com\/wp-json\/wp\/v2\/media?parent=551"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/ortoinbalcone.com\/wp-json\/wp\/v2\/categories?post=551"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/ortoinbalcone.com\/wp-json\/wp\/v2\/tags?post=551"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}