Ask the Steward
Question: My pine tree drops a lot of pine cones and I’d like to grow some new trees from their seed. Do I just plant the whole cone?
Answer: While the cone is the fruiting body of the pine tree it is not actually the seed. The cone is made up of several parts and the most obvious are the scales that make up the bulk of the cone and protect the seeds while they develop and mature. Under each of the scales there will usually be 2 small winged seeds. As the cone and seed matures, the cones dry and begin to peel back to expose the seeds, which are dislodged and dispersed by wind and natural elements. Wildlife, such as squirrels, can also disperse seed as they break apart cones in search of food. While several pine species are grown in Indiana, there are only 2 pine species native to the state- White pine and Virginia pine. Both can be grown from seed, but you’ll need to obtain the seed from the cones after they have matured and before the good seed has blown away or been carried off. Look for cones in late summer that are beginning to dry and the scales beginning to peel back. Place the cones in a paper bag and let them dry further. As they dry the seeds will fall out into the bag and can be easily collected.
To sort out good seed from bad, place the seeds in a container of water and let soak overnight. Discard any seed that floats as its embryo is probably dead. Drain the seed and pat dry and then place the seed in a freezer bag with moistened perlite and refrigerate for 60-90 days. Check the mixture periodically and moisten as needed to prevent drying out. After this period of stratification the seed is ready to plant. Plant ¼ inch deep in a good potting soil mix and keep uniformly moist during germination and early growth period. Germination should begin to occur in two to six weeks. Transplant the seedlings when they are 6-10” tall. This is a great activity to include the next generation of woodland owners. You can find more detailed information on the web.
Question: My forester talks about a ‘site index’ number for my woods. What does that mean?
Answer: ‘Site Index’ is one of those measurements that every serious, and even not so serious, woodland owner should know about their property. Site index is the most commonly used method of assessing site quality in North America and is defined as the average height of a certain number of dominants and codominant trees in the stand at an index age- usually 50 years.
Or, to put more simply it is a measure of site productivity reflected by how tall the dominant, healthy trees in your woods can be expected to grow in 50 years. For example, a site index of 85 for Red Oak means Red Oak trees that are unsuppressed and free to grow can be expected to attain a height of 85 feet at 50 years of age. Similarly, a site index of 70 for Red Oak would yield trees only 70 feet tall at age 50. Obviously, a site index of 85, yielding taller trees, is much more productive than a site than can only grow trees 70 feet in height during the same period.
To add some confusion, not all tree species grow the same rate on the same site. For example: a wooded area with and index of 85 for Red Oak, may also have a site index of 100 for Tulip poplar. Why- Tulip trees on good sites will grow faster, taller and quicker than Red Oak or other species on certain sites. So, when stating a ‘site index’ you must always identify the reference tree species to have full understanding. While the measure is relatively simple, there are many underlying factors and natural processes which add complexity
Across your woodland property you are likely to have a variety of soils, topography and slope aspects, with varying degrees of productivity. Each of these will also vary in site index. You may have intuitively noticed certain areas of your woodland grows taller or shorter trees, and areas where certain tree species perform better than others.
You can roughly approximate site index on your property by aging a few medium aged (35-60 years old) dominant trees, measuring their height and then extrapolating what it’s height would likely be at age 50. More accurate determination requires the use of develop site index curves and other methods. Indiana soils surveys also list average site index for many of Indiana’s soil types. What’s your site index?