{"product_id":"grodan-rockwool-blocks","title":"Grodan Rockwool Blocks for Cuttings and Seedlings","description":"\u003ch2\u003eConsistent Rooting from a Cube That Holds Its Shape\u003c\/h2\u003e\u003cp\u003eGrodan rockwool blocks are a high-performance, reliable grow media made to deliver strong growth through the \u003cstrong\u003epropagation phase\u003c\/strong\u003e. Available with a \u003cstrong\u003e2.5cm small hole\u003c\/strong\u003e or a \u003cstrong\u003e3.6cm large hole\u003c\/strong\u003e, they suit fine seed and small cuttings through to thicker stems. The cube is \u003cstrong\u003esolid and holds its shape\u003c\/strong\u003e, so it does not slump when saturated. They offer excellent \u003cstrong\u003esaturation and re-saturation\u003c\/strong\u003e, a positive effect on \u003cstrong\u003eEC refreshment\u003c\/strong\u003e and distribution, and an \u003cstrong\u003eexcellent air-to-water ratio\u003c\/strong\u003e for rich root growth.\u003c\/p\u003e\u003ch3\u003eKey Benefits\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eTwo hole sizes\u003c\/strong\u003e - \u003cstrong\u003e2.5cm\u003c\/strong\u003e for seed and fine cuttings, \u003cstrong\u003e3.6cm\u003c\/strong\u003e for thicker stems.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eExcellent air-to-water ratio\u003c\/strong\u003e - roots get oxygen as well as moisture.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSaturation and re-saturation\u003c\/strong\u003e - takes water back up evenly rather than channelling.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBetter EC distribution\u003c\/strong\u003e - fewer hot spots and less salt build-up in the cube.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eHolds its shape\u003c\/strong\u003e - solid, durable and resistant through handling and transplant.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eStrictest quality standards\u003c\/strong\u003e - batch consistency you can plan around.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eSlow, Patchy Rooting and Transplant Shock\u003c\/h3\u003e\u003cp\u003eCuttings that root at different rates wreck a schedule, and the culprit is usually a substrate that holds too much water or dries unevenly. Waterlogged cubes starve roots of oxygen, giving weak roots and slow growth; dry pockets cause poor nutrient uptake and stalled strike rates. A balanced air-to-water ratio and even re-saturation mean roots develop into a firm plug, so transplant shock is minimal.\u003c\/p\u003e\u003ch3\u003eHow to Use\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003ePre-soak:\u003c\/strong\u003e soak the blocks in water adjusted to around \u003cstrong\u003epH 5.5\u003c\/strong\u003e before use.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDrain:\u003c\/strong\u003e let excess water drain off - never squeeze the blocks, as that ruins the structure.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInsert:\u003c\/strong\u003e set a seed, or a fresh cutting dipped in rooting gel, into the hole and firm gently.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eEnvironment:\u003c\/strong\u003e keep the tray in a propagator at around 21-25C, opening the vents gradually.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWatering:\u003c\/strong\u003e keep the block moist but never saturated - overwatering is the top cause of failed cuttings.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTransplant:\u003c\/strong\u003e move on once roots show at the sides or base, into a larger block, slab or pot.\u003c\/li\u003e\n\u003c\/ul\u003e\u003cdiv class=\"hcs-specs\"\u003e\n\u003ch3\u003eTechnical Specifications\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eType:\u003c\/strong\u003e Rockwool propagation blocks\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSizes:\u003c\/strong\u003e 2.5cm (small hole) and 3.6cm (large hole)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eStage:\u003c\/strong\u003e Propagation - seeds and cuttings\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eStructure:\u003c\/strong\u003e Solid, holds its shape when saturated\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWater Handling:\u003c\/strong\u003e Excellent saturation and re-saturation\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eEC:\u003c\/strong\u003e Positive effect on EC refreshment and distribution\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAir-to-Water Ratio:\u003c\/strong\u003e Optimised for rich root growth\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRecommended Soak pH:\u003c\/strong\u003e Around 5.5\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e","brand":"Grodan","offers":[{"title":"2.5cm (Small Hole) \/ Single","offer_id":53445764481290,"sku":null,"price":0.4,"currency_code":"GBP","in_stock":true},{"title":"2.5cm (Small Hole) \/ Strip of 8","offer_id":53445764514058,"sku":null,"price":2.95,"currency_code":"GBP","in_stock":true},{"title":"2.5cm (Small Hole) \/ Box of 384","offer_id":53445764546826,"sku":null,"price":131.95,"currency_code":"GBP","in_stock":true},{"title":"3.6cm (Large Hole) \/ Single","offer_id":53445764579594,"sku":null,"price":0.4,"currency_code":"GBP","in_stock":true},{"title":"3.6cm (Large Hole) \/ Strip of 8","offer_id":53445764612362,"sku":null,"price":2.95,"currency_code":"GBP","in_stock":true},{"title":"3.6cm (Large Hole) \/ Box of 384","offer_id":53445764645130,"sku":null,"price":131.95,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0748\/7127\/5786\/files\/grow-media-3-6cm-hole-box-of-384-3-inch-7-5cm-grodan-rockwool-blocks-39901489758423.webp?v=1785293055","url":"https:\/\/hydrocropshop.co.uk\/products\/grodan-rockwool-blocks","provider":"Hydro Crop Shop","version":"1.0","type":"link"}