The basic idea of a Seed Crown® can be embodied in a variety of configurations and manufactured in an assortment of materials and sizes.  After much trial and error, the first manufactured prototypes used the design shown below to the right:

The key goals for any Seed Crown® design are to make it not worth the trouble for predators to get in while making it easy for plants to get out, and for the shelter either to be reusable or to degrade without harmful side effects under a normal forest management regime. Important features of the prototype design include the open bottom with peg holes to for easy installation over a planted seed or seedling and a solid lower base wall with separate vertical members that act as palisades. The transition from a solid base to abundant side palisades and then to comparatively fewer spikes bending over the top opening recognizes that larger birds and mammals most likely to approach from above can be deterred by lesser obstruction than smaller mammals or even insects that might approach closer to the ground. Also, having the spikes bend inward over the top helps deflect leaf litter and makes stacking much easier. The absence of horizontal elements above ground level and the reducing number of vertical impediments moving higher from the ground serve to reduce interference with plants growing inside the Seed Crown® (whether desired seedlings or other cohabitant vegetation). Because the first model available to the public is made from recyclable plastic intended to be used over and over again, their design includes a fracture zone along the base for easy removal from larger plants.

The initial run of manufactured Seed Crowns® prototypes included versions made from plant-based poly lactic acid (“PLA”) and traditional polypropylene (“PP”) plastic materials, and PLA and PP mixed with wheat straw. While PLA may be the least expensive of the plant-based plastics in today’s market, it is still much more expensive than PP and, while theoretically compostable under ideal conditions, pure PLA is nearly as persistent as PP in real world environments. As a result, the first model for general distribution is made from PP while development of a truly biodegradable continues.

One last feature deserves special mention. Seed Crowns® are designed to stack in sleeves like drink cups. A package of 50 units stands about 16” tall and weighs less than two pounds. As a result, they are sufficiently lightweight and compact for an individual to carry a day’s worth of shelters in a backpack along with a hardy lunch and drinking water, making planting in remote locations far more feasible than is the case with nursery stock.

As explored in the Trials section, field testing of manufactured prototypes begin in October 2022. Go to the Precision Direct Seeding YouTube Channel to view a demonstration video.

Effects of Prescribed Fire

To date, the prototypes have been exposed to low intensity fires conducted at 14 months and about two years. As the photos below show, while the seedlings appear just fine even at 14 months, the degree to which either the PLA or PP shelter material burned or melted was highly variable and very few locations saw the material completely consumed.  Burning at three years may produce better results because needles from the longleaf seedlings will contribute meaningful fuel in contact with the shelter material. As noted earlier, efforts are underway to develop a single-use model from plant fiber that would both be legitimately biodegradable and be more completely consumed by fire, which would afford a true one-touch method and might conceivably be adapted to mechanical planting.

Results of prescribed fire on 14 month-old seedlings under PLA shelter.

Results of prescribed fire on two year-old seedling under PP shelter