Georgian Court University

Planting Amendments

 1.Fertilizer

 A slow release fertilizer such as Osmocote (anaylsis varies depending on release time) or an organic product such as Ocean Gro (5-5-0) that supplies a small amounts of nitrogen and moderate amount of phosphorus would be beneficial.  While older protocols did suggest broadcast fertilization of beach grasses, dunes are now considered environmentally sensitive buffers to aquatic habitats and broadcast fertilizer applications in such habitats are no longer acceptable because the nutrients from such habitats often leach rapidly from there into the nearby water, causing pollution.  We recommend that a small amount of fertilizer be added to the hole as the plants are installed

 2. Compost / seaweed. Adding organic materials such as compost is helpful from a water holding standpoint, but any of these materials should also be mixed in with some sand to prevent a water barrier (zone of discontinuity between different sized pore spaces) from being created between the roots and the pure sand substrate.  Similarly, if one plants a containerized shrub growing in Promix (high organic potting soil) into a hole surrounded by pure sand, this will create a discontinuous water barrier between sand and Promix.  To help the plant thrive it is important to back fill the hole with a mixture of Promix and sand (about a 50/50 ratio).

3. Terrasorb (water absorbing gel)

Terasotb brand name product of a product that keeps roots moist when transplanting bareroot seedlings and helps water maintain water absorption to roots during dry periods. It is good insurance and adds minimal cost to the planting. 1 pound of crystalline product which costs $6.00-$7.00 added to about 30 gallons of water will treat 15,000 bareroot seedlings.  

4. Mycorrhizae fungi

Mycorrhizae fungi promote plant vigor, add disease resistance, and can increase survival while improving soil for future plantings. A 3-lb. jar of Bio/Organics Mycorrhizae Inoculum will treat about 1500 plants at a cost of $80.00. This adds about $0.05/plant to the cost of the planting.

-The jury is still out on the effectiveness of the commercially produced mycorrhizal inoculant. If an additional $0.05 per plant is not a problem from a project budget standpoint, it won’t hurt to add the inoculum at planting time.

Remember: walking on the dune is probably more detrimental than any watering or fertilizing you do one you have finished your planting.

Suppliers of Planting Amendments

Content of these pages was contributed by Chris Miller, Jon Miller, Michael Peek, Ray Bukowski, and Louise Wootton.  Edited by Louise Wootton.