Whitcomb - Nursery Practices 2


Suppose you could marry the good news aspects of both field and container production. Would you do it?


With the latest technology, not only is this possible, it is one of the most economical and efficient production methods when all factors and costs are considered, and involves less risk and less labor.

Here is what I would do, and why. However, giving all the details would make a far longer article than is desirable, so here is the essence of the method. The long version will be available in the revised version of my book Production of Landscape Plants, available soon as a hardcover book or as a CD.

The basis of the system is to work with the plant and avoid restrictions to growth. Remember a plant runs on energy, and the more productive the leaves at manufacturing the energy needed for growth of tops and roots, the better. Avoid the common mistakes that limit growth by techniques such as treating water to lower bicarbonates, applying modest rates of low water-solubility herbicides so as to avoid root damage, focus on the entire nutrition of the plant, because it is how all the essential elements work in concert that counts, not just the effect of one or two elements, and so on.

Consider the following steps:

  1. Plant seed in RootMaker tm propagation containers. This destroys the taproot within a few days after germination and stimulates secondary root branching by air-pruning the roots not only on the bottom but on the sides. It creates a root system with root tips ready to grow radially as well as downward when transplanted. Done properly and in a timely manner, root systems far superior to those that occur in nature can be produced faster and more consistently. (This procedure also works for cuttings.)

  2. Transplant the seedlings after 10-16 weeks into one- or three-gallon RootMaker tm containers, which continues the air-root pruning for the full height of the container sidewall to stimulate root branching, and accelerates plant growth. Or transplant seedlings into knit bags held in the cavities of cinderblocks. or into the five-gallon RootMaker tm Grounder if your soil drains well.

  3. Leave all but the most aggressive side branches on the young trees. Continue this, leaving all lower limbs and foliage, for the first two growing seasons or longer. Remove the lower limbs only after good stem strength is achieved, or roughly one growing season before experience teaches you that the trees are to be sold at two- to three-inch stem diameter. The lower limbs on young trees are the main contributors of energy to boost stem diameter and root growth.

  4. Prepare field soil by testing for nutrient levels, and make adjustments for anything that is deficient or in excess. Till the soil deeply to improve aeration and supply oxygen for root growth.

  5. During September or October of the first year, plant the vigorous, good quality seedlings into the field to grow on. Throw the runts away. Remember, it is better and cheaper to throw any marginal liner away at this point than to grow it on for one or two more years before having to dispose of it as a cull.

  6. Plant the trees in the field in fabric containers made of the latest knit fabric grow bag technology available from Rootmaker Products Company. All openings in this special knit fabric are 5/64 inch in diameter. This is the smallest opening through which the roots of a woody plant will grow. As soon as the the root increases even slightly in diameter it is girdled.

  7. Drip-irrigate the first year and whenever rains are lacking in successive years if good quality water is available.

  8. Fertilize, control disease and insects just as you would with conventional field production.

  9. Three-inch caliper trees can be grown and harvested with ease in an 18-inch diameter knit fabric container. When the trees reach market size, harvest while they are dormant (the time when demand for labor is lowest).

  10. Harvest the trees using a double loop nylon strap around the trunk and a lifting arm on a tractor or skid loader. Working with one helper, I have harvested 80 dormant trees of roughly three-inch caliper in one hour with this method. Roots that have grown through the knit fabric container break at the outside face of the fabric as the tree is pulled from the ground.

  11. Strip away the fabric. The knit fabric comes off far more easily than the early versions of grow bags.

    Here's where the marriage comes in ...

    1 | Next (3)