Calculating Pounds of Seed Needed

To convert seedlings needed to pounds of seed needed:

• Pounds of seed needed = seedlings needed/seedlings per pound of seed

Seedlings needed—Estimated seedlings needed for a particular species in a seed zone and elevation band.

Seedlings per pound of seed—Average number of seedlings that can be produced from a pound of seed. The average can be obtained from your nursery or by using regional or local averages. Production can differ widely based on the stock types (2-0 bareroot, 1-0 bareroot, container) and source (for instance, seed orchards rather than seed from wild stands). At this point, consider the seed source that is likely to be used. Estimates of the seedlings per pound of seed are available in the Seeds of Woody Plants in the United States.

Example: If 300 acres are to be planted at a rate of 350 ponderosa pine trees per acre. A total of 105,000 trees are needed. Assuming the production for bareroot ponderosa pine is 5,000 seedlings per pound of seed based on conversion from your local nursery, the following equation applies:

• 105,000 PP seedlings needed / 5,000 PP seedlings per pound = 21 pounds of PP seed.

Be sure that the conversion factors you are using are identical; if one number is per thousand (M) trees, then both should be.

Refer to the equation in Planning the Collection—How Many Cones To Collect to convert pounds of seed to bushels of cones.