{"id":3392,"date":"2026-09-24T10:00:54","date_gmt":"2026-09-24T10:00:54","guid":{"rendered":"https:\/\/www.tomat-pomidor.com\/en\/?p=3392"},"modified":"2026-09-27T09:01:05","modified_gmt":"2026-09-27T09:01:05","slug":"warm-cold-greenhouse-soil","status":"publish","type":"post","link":"https:\/\/www.tomat-pomidor.com\/en\/warm-cold-greenhouse-soil\/","title":{"rendered":"How to Warm Cold Greenhouse Soil for Early Tomatoes"},"content":{"rendered":"\n\n<div class=\"kk-star-ratings kksr-auto kksr-align-left kksr-valign-top\"\n    data-payload='{&quot;align&quot;:&quot;left&quot;,&quot;id&quot;:&quot;3392&quot;,&quot;slug&quot;:&quot;default&quot;,&quot;valign&quot;:&quot;top&quot;,&quot;ignore&quot;:&quot;&quot;,&quot;reference&quot;:&quot;auto&quot;,&quot;class&quot;:&quot;&quot;,&quot;count&quot;:&quot;0&quot;,&quot;legendonly&quot;:&quot;&quot;,&quot;readonly&quot;:&quot;&quot;,&quot;score&quot;:&quot;0&quot;,&quot;starsonly&quot;:&quot;&quot;,&quot;best&quot;:&quot;5&quot;,&quot;gap&quot;:&quot;5&quot;,&quot;greet&quot;:&quot;Share your rating&quot;,&quot;legend&quot;:&quot;0\\\/5 - (0 votes)&quot;,&quot;size&quot;:&quot;24&quot;,&quot;title&quot;:&quot;How to Warm Cold Greenhouse Soil for Early Tomatoes&quot;,&quot;width&quot;:&quot;0&quot;,&quot;_legend&quot;:&quot;{score}\\\/{best} - ({count} {votes})&quot;,&quot;font_factor&quot;:&quot;1.25&quot;}'>\n            \n<div class=\"kksr-stars\">\n    \n<div class=\"kksr-stars-inactive\">\n            <div class=\"kksr-star\" data-star=\"1\" style=\"padding-right: 5px\">\n            \n\n<div class=\"kksr-icon\" style=\"width: 24px; height: 24px;\"><\/div>\n        <\/div>\n            <div class=\"kksr-star\" data-star=\"2\" style=\"padding-right: 5px\">\n            \n\n<div class=\"kksr-icon\" style=\"width: 24px; height: 24px;\"><\/div>\n        <\/div>\n            <div class=\"kksr-star\" data-star=\"3\" style=\"padding-right: 5px\">\n            \n\n<div class=\"kksr-icon\" style=\"width: 24px; height: 24px;\"><\/div>\n        <\/div>\n            <div class=\"kksr-star\" data-star=\"4\" style=\"padding-right: 5px\">\n            \n\n<div class=\"kksr-icon\" style=\"width: 24px; height: 24px;\"><\/div>\n        <\/div>\n            <div class=\"kksr-star\" data-star=\"5\" style=\"padding-right: 5px\">\n            \n\n<div class=\"kksr-icon\" style=\"width: 24px; height: 24px;\"><\/div>\n        <\/div>\n    <\/div>\n    \n<div class=\"kksr-stars-active\" style=\"width: 0px;\">\n            <div class=\"kksr-star\" style=\"padding-right: 5px\">\n            \n\n<div class=\"kksr-icon\" style=\"width: 24px; height: 24px;\"><\/div>\n        <\/div>\n            <div class=\"kksr-star\" style=\"padding-right: 5px\">\n            \n\n<div class=\"kksr-icon\" style=\"width: 24px; height: 24px;\"><\/div>\n        <\/div>\n            <div class=\"kksr-star\" style=\"padding-right: 5px\">\n            \n\n<div class=\"kksr-icon\" style=\"width: 24px; height: 24px;\"><\/div>\n        <\/div>\n            <div class=\"kksr-star\" style=\"padding-right: 5px\">\n            \n\n<div class=\"kksr-icon\" style=\"width: 24px; height: 24px;\"><\/div>\n        <\/div>\n            <div class=\"kksr-star\" style=\"padding-right: 5px\">\n            \n\n<div class=\"kksr-icon\" style=\"width: 24px; height: 24px;\"><\/div>\n        <\/div>\n    <\/div>\n<\/div>\n                \n\n<div class=\"kksr-legend\" style=\"font-size: 19.2px;\">\n            <span class=\"kksr-muted\">Share your rating<\/span>\n    <\/div>\n    <\/div>\n<p><script type=\"application\/ld+json\">\n{\n  \"@context\": \"https:\/\/schema.org\",\n  \"@type\": \"QAPage\",\n  \"mainEntity\": {\n    \"@type\": \"Question\",\n    \"name\": \"How can I quickly warm up cold greenhouse soil for early tomato planting?\",\n    \"text\": \"My tomato seedlings are getting huge, but the deep soil in my unheated greenhouse is still freezing cold. What are some hacks to warm up the soil faster so I can plant them out early?\",\n    \"answerCount\": 1,\n    \"datePublished\": \"2021-04-06T10:00:00+03:00\",\n    \"author\": {\n      \"@type\": \"Person\",\n      \"name\": \"gala7496\",\n      \"url\": \"https:\/\/www.tomat-pomidor.com\/profile\/61096-gala7496\/\"\n    },\n    \"acceptedAnswer\": {\n      \"@type\": \"Answer\",\n      \"text\": \"The fastest way to warm up the root zone is the 'bag method'. Dig your planting holes early, but instead of leaving the excavated soil in piles, put it into black plastic grocery bags and leave them on the greenhouse paths. The soil in the bags will bake in the sun and get incredibly warm. When you plant your tomatoes, use this pre-warmed soil to backfill the holes.\",\n      \"datePublished\": \"2021-04-06T15:30:00+03:00\",\n      \"url\": \"https:\/\/www.tomat-pomidor.com\/en\/your-article-slug\/#answer\",\n      \"author\": {\n        \"@type\": \"Person\",\n        \"name\": \"Aleksan9ra\",\n        \"url\": \"https:\/\/www.tomat-pomidor.com\/profile\/56700-aleksan9ra\/\"\n      },\n      \"upvoteCount\": 84\n    }\n  }\n}\n<\/script><\/p>\n<div class=\"tldr-box\" style=\"background: #f4f9f4; padding: 20px; border-left: 5px solid #4CAF50; margin-bottom: 30px; border-radius: 4px;\">\n<h3>\ud83d\udccc Quick Summary (TL;DR): Warming Cold Greenhouse Soil<\/h3>\n<ul>\n<li>\ud83c\udf21\ufe0f <strong>The Core Problem:<\/strong> In early spring, the top layer of dirt in a high tunnel or greenhouse might feel warm, but just a few inches down, it&#8217;s ice-cold. Planting tender tomatoes in cold soil will severely stunt their roots.<\/li>\n<li>\ud83d\udca1 <strong>The Bag Hack:<\/strong> Dig your planting holes a week or two early. Scoop the excavated soil into black plastic grocery bags and leave them in the sun. Use this sun-baked soil to backfill when you finally plant!<\/li>\n<li>\u26a0\ufe0f <strong>The &#8220;Seedling Shuffle&#8221;:<\/strong> Lugging heavy cell trays in and out of the greenhouse for hardening off is backbreaking work. Many growers opt to set up a mini cold-frame *inside* the greenhouse with frost blankets and a small space heater for frosty nights.<\/li>\n<\/ul>\n<\/div>\n<div class=\"add-review-cta\" style=\"margin: 20px 0; padding: 15px; background: #f9f9f9; border-left: 4px solid #4CAF50; border-radius: 4px;\"><strong>\ud83d\udcac Is your greenhouse dirt still too cold for planting out?<\/strong> <a href=\"#wpdcom\">Share your soil-warming tricks in the comments!<\/a><\/div>\n<div class=\"forum-post\">\n<div class=\"author-header\">\n<div class=\"forum-avatar\">A<\/div>\n<div class=\"author-meta\">\n<div class=\"author-name\">Aleksan9ra (Ludmila) <span class=\"author-stats\">\u2b50 Pro Grower (15,056 posts)<\/span><\/div>\n<div class=\"author-geo\">\ud83d\udccd Moscow Region (USDA Zone 4)<\/div>\n<\/div>\n<\/div>\n<div class=\"post-content\">I&#8217;m hoping to plant my tomatoes out early, but we&#8217;ll see if I can pull it off. The top layer of soil in the center bed is nice and warm, but dig down a bit and it&#8217;s ice-cold. And along the edges, because snow is still banked up against the outside of the greenhouse, the cold just seeps right in. If the snow melts by the weekend and we get a warm spell, it might work. Still got two weeks until my target plant-out date (April 20th).<\/div>\n<\/div>\n<div class=\"forum-post\">\n<div class=\"author-header\">\n<div class=\"forum-avatar\">T<\/div>\n<div class=\"author-meta\">\n<div class=\"author-name\">Tiffany (Julia) <span class=\"author-stats\">\u2b50 Pro Grower<\/span><\/div>\n<div class=\"author-geo\">\ud83d\udccd Gardening in USDA Zone 4 conditions<\/div>\n<\/div>\n<\/div>\n<div class=\"post-content\">Hey Ludmila! My setup is pretty similar, I just use in-ground beds, no raised beds, and my greenhouse doesn&#8217;t have a concrete foundation. I lay clear plastic over the damp dirt inside to trap the heat. I also lay it down outside, right along the foundation line, so the soil there warms up too and stops the cold from leaching in.<\/div>\n<\/div>\n<div class=\"forum-post\">\n<div class=\"author-header\">\n<div class=\"forum-avatar\">V<\/div>\n<div class=\"author-meta\">\n<div class=\"author-name\">Valtwelve (Valery) <span class=\"author-stats\">\u2b50 Pro Grower<\/span><\/div>\n<div class=\"author-geo\">\ud83d\udccd Volga Region (USDA Zone 4)<\/div>\n<\/div>\n<\/div>\n<div class=\"post-content\">\n<blockquote><p><strong>Tiffany (Julia) wrote:<\/strong><br \/>\nI also lay it down outside, right along the foundation line, so the soil there warms up too&#8230;<\/p><\/blockquote>\n<p>But at night, that outside dirt is gonna cool down fast under just one layer of plastic. Now, a double layer with an air gap might work&#8230;<\/p>\n<p>Wouldn&#8217;t it be better to dig a shallow trench around the outside perimeter, drop in some 2-inch (5 cm) rigid foam board, and bury it? Just thinking out loud here, making me want to try it, even though my foundation is concrete covered with dirt. My only worry is field mice. Wouldn&#8217;t that foam board just turn into a luxury winter condo for them?<\/p>\n<\/div>\n<\/div>\n<div class=\"forum-post\">\n<div class=\"author-header\">\n<div class=\"forum-avatar\">R<\/div>\n<div class=\"author-meta\">\n<div class=\"author-name\">Russi (Anna) <span class=\"author-stats\">\u2b50 Pro Grower<\/span><\/div>\n<div class=\"author-geo\">\ud83d\udccd Moscow Region (USDA Zone 4)<\/div>\n<\/div>\n<\/div>\n<div class=\"post-content\">\n<p>Hey everyone! Well, I couldn&#8217;t stand looking at my 20-inch (50 cm) leggy indoor monsters anymore, so I hauled them out to the greenhouse today. I laid down a plastic pallet on the center bed, popped some hoops over it, and threw on a double layer: a frost blanket on the bottom, and clear poly on top. Plugged in a tiny space heater for the night.Yesterday, on the other end of the bed (also under plastic), I direct-sowed some radishes and arugula. Even though we had a hard freeze last night (ice on the pond!), they didn&#8217;t freeze. I also kicked the aster and cabbage seed trays out there. Set them up on upturned crates so they aren&#8217;t sitting directly on the freezing dirt. We&#8217;ll see how they handle the night! \ud83d\ude42<\/p>\n<\/div>\n<\/div>\n<div class=\"forum-post\">\n<div class=\"author-header\">\n<div class=\"forum-avatar\">N<\/div>\n<div class=\"author-meta\">\n<div class=\"author-name\">Nessi (Nelya) <span class=\"author-stats\">\u2b50 Pro Grower<\/span><\/div>\n<div class=\"author-geo\">\ud83d\udccd Moscow Region (USDA Zone 4)<\/div>\n<\/div>\n<\/div>\n<div class=\"post-content\">I&#8217;ve been doing the &#8220;seedling shuffle&#8221;, lugging trays in and out for a week now. My lower back is absolutely screaming, but the plants look great. My cabbage, parsley, and celery starts are now living in the greenhouse full-time under row covers.<\/div>\n<\/div>\n<div id=\"answer\" class=\"forum-post\">\n<div class=\"author-header\">\n<div class=\"forum-avatar\">A<\/div>\n<div class=\"author-meta\">\n<div class=\"author-name\">Aleksan9ra (Ludmila) <span class=\"author-stats\">\u2b50 Pro Grower (15,056 posts)<\/span><\/div>\n<div class=\"author-geo\">\ud83d\udccd Moscow Region (USDA Zone 4)<\/div>\n<\/div>\n<\/div>\n<div class=\"post-content\">\n<blockquote><p><strong>Nessi (Nelya) wrote:<\/strong><br \/>\nMy lower back is absolutely screaming&#8230;<\/p><\/blockquote>\n<p>Nelya, that&#8217;s exactly why I refuse to lug them back and forth. My back can&#8217;t take it, plus the garden paths are icy in the mornings, it&#8217;s a total slip hazard!<\/p>\n<p>Tomorrow I&#8217;m starting greenhouse prep for the tomatoes. First, I&#8217;ll turn the beds, then dig the planting holes. <strong>Here is my trick:<\/strong> I scoop the soil from the holes into black plastic grocery bags and just leave them sitting on the greenhouse paths.<\/p>\n<p>This does three things: the beds warm up naturally, the open holes allow heat to reach deeper into the ground, and the dirt in the bags absolutely bakes in the sun. When it&#8217;s time to plant, I use that hot bagged soil to backfill around the roots!<\/p>\n<\/div>\n<\/div>\n<div class=\"forum-post\">\n<div class=\"author-header\">\n<div class=\"forum-avatar\">R<\/div>\n<div class=\"author-meta\">\n<div class=\"author-name\">Raduga (Galina) <span class=\"author-stats\">\u2b50 Pro Grower (6,149 posts)<\/span><\/div>\n<div class=\"author-geo\">\ud83d\udccd St. Petersburg (USDA Zone 4\/5)<\/div>\n<\/div>\n<\/div>\n<div class=\"post-content\">\n<blockquote><p><strong>Aleksan9ra (Ludmila) wrote:<\/strong><br \/>\nThis does three things: the beds warm up naturally, the open holes allow heat to reach deeper into the ground&#8230;<\/p><\/blockquote>\n<p>Ludmila, I think that&#8217;s a brilliant idea!<\/p>\n<p>I actually had something similar happen by accident. Last fall, I pre-dug my planting holes and stuck empty 5-liter (1.3-gallon) water jugs into them. Come spring, I was absolutely thrilled with the results!<\/p>\n<\/div>\n<\/div>\n<div class=\"forum-post\">\n<div class=\"author-header\">\n<div class=\"forum-avatar\">A<\/div>\n<div class=\"author-meta\">\n<div class=\"author-name\">Aleksan9ra (Ludmila) <span class=\"author-stats\">\u2b50 Pro Grower (15,056 posts)<\/span><\/div>\n<div class=\"author-geo\">\ud83d\udccd Moscow Region (USDA Zone 4)<\/div>\n<\/div>\n<\/div>\n<div class=\"post-content\">Galya, the idea literally hit me today while I was out working in the greenhouse. Honestly, the more I think about it, the more I pat myself on the back! \ud83d\ude01The thing is, my greenhouse beds are pretty narrow. When I dig planting holes, there&#8217;s nowhere to pile the excavated dirt, it just slides right back into the hole. That&#8217;s one issue. The other is that a loose mound of dirt takes twice as long to warm up.<\/p>\n<p>But in bags out on the pathway? That dirt will bake in just one day, and it&#8217;ll act as a thermal mass, radiating heat back out at night. You don&#8217;t even need that many bags, heavy-duty black trash bags work best.<\/p>\n<\/div>\n<\/div>\n<div class=\"editor-note\" style=\"background: #eef7ff; padding: 15px; border-left: 4px solid #2196F3; margin-top: 15px; font-size: 1.2em;\"><strong>\ud83d\udc68\u200d\ud83c\udf3e Editor&#8217;s Greenhouse Tips:<\/strong><br \/>\nLudmila&#8217;s &#8220;soil in a bag&#8221; hack is brilliant for cold-climate gardeners! Tomato roots suffer severe transplant shock if placed in soil colder than 60\u00b0F (15\u00b0C). Pre-heating the backfill soil acts like a warm blanket for the root ball.Regarding Valery&#8217;s foam board idea, his fears are 100% justified. Never bury unprotected polystyrene foam around a greenhouse. Field mice and voles will immediately tunnel into it to build winter nests, eventually finding their way inside to eat your seedlings!<\/div>\n","protected":false},"excerpt":{"rendered":"<p>\ud83d\udccc Quick Summary (TL;DR): Warming Cold Greenhouse Soil \ud83c\udf21\ufe0f The Core Problem: In early spring, the top layer of dirt in a high tunnel or greenhouse might feel warm, but just a few inches down, it&#8217;s ice-cold. Planting tender tomatoes in cold soil will severely stunt their roots. \ud83d\udca1 The Bag Hack: Dig your planting &#8230; <a title=\"How to Warm Cold Greenhouse Soil for Early Tomatoes\" class=\"read-more\" href=\"https:\/\/www.tomat-pomidor.com\/en\/warm-cold-greenhouse-soil\/\" aria-label=\"Read more about How to Warm Cold Greenhouse Soil for Early Tomatoes\">Read more<\/a><\/p>\n","protected":false},"author":1,"featured_media":3392,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[806,529],"tags":[861,862],"class_list":["post-3392","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-grower-diaries","category-growing-tomatoes","tag-cold-greenhouse-soil","tag-soil-for-early-tomatoes"],"_links":{"self":[{"href":"https:\/\/www.tomat-pomidor.com\/en\/wp-json\/wp\/v2\/posts\/3392","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.tomat-pomidor.com\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.tomat-pomidor.com\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.tomat-pomidor.com\/en\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.tomat-pomidor.com\/en\/wp-json\/wp\/v2\/comments?post=3392"}],"version-history":[{"count":4,"href":"https:\/\/www.tomat-pomidor.com\/en\/wp-json\/wp\/v2\/posts\/3392\/revisions"}],"predecessor-version":[{"id":3758,"href":"https:\/\/www.tomat-pomidor.com\/en\/wp-json\/wp\/v2\/posts\/3392\/revisions\/3758"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.tomat-pomidor.com\/en\/wp-json\/wp\/v2\/posts\/3392"}],"wp:attachment":[{"href":"https:\/\/www.tomat-pomidor.com\/en\/wp-json\/wp\/v2\/media?parent=3392"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.tomat-pomidor.com\/en\/wp-json\/wp\/v2\/categories?post=3392"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.tomat-pomidor.com\/en\/wp-json\/wp\/v2\/tags?post=3392"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}