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ARS Home » Southeast Area » Poplarville, Mississippi » Southern Horticultural Research Unit » Research » Publications at this Location » Publication #200783

Title: "Whole Tree", a Promising Alternative to Traditional Peat-based Greenhouse Substrates

item Fain, Glenn

Submitted to: Ornamental Outlook
Publication Type: Trade Journal
Publication Acceptance Date: 10/1/2006
Publication Date: 11/1/2006
Citation: Fain, G.B. 2006. "Whole Tree", a Promising Alternative to Traditional Peat-based Greenhouse Substrates. Ornamental Outlook Vol 15 No. 11 pp 30-31.

Interpretive Summary: Not necessary with a trade Journal.

Technical Abstract: Greenhouse crops, with few exceptions, are grown in substrates made up primarily of Canadian sphagnum peat. Of major concern is that peat is a non-renewable resource which at some point in the future will be depleted. Another concern is the increased cost of peat due to the rise in transportation costs. A cost effective, sustainable, alternative substrate is made of whole pine trees (Pinus taeda) which are harvested from pine plantations at the thinning stage, chipped and further ground to specifications depending on the crops to be grown. WholeTree is a product comprised of all shoot portions of the tree including wood, bark, limbs, needles and cones if present. The substrate is mixed with necessary amendments and used fresh. Our research is a joint effort with scientists at Auburn University’s Department of Horticulture (Dr. Charles H. Gilliam and Dr. Jeff L. Sibley) and School of Forestry and Wildlife Sciences (Dr. Thomas V. Gallagher) as well as growers in the Green Industry. Using WholeTree substrates will require special attention to nutrition, with most crops requiring slightly more nitrogen – at least initially, to produce similar growth results to standard peat based substrates. In one study it took as little as 800 ppm additional nitrogen over a 35 day crop cycle to produce similar results to a peat based substrate in a crop of Lantana camara. Other studies indicate the addition of a starter charge of 2 – 6 lbs/yd3 7-3-10 may in some cases result in increased growth depending on plant species. One of the unique things about “WholeTree” substrates is that you can consistently produce a product with target physical properties without the need for the addition of other components such as bark or perlite which are commonly added to commercial peat substrates. We are also developing and testing a WholeTree container nursery substrate as an alternative to pine bark. Tests with these product as well show great potential as well.