Pretend for a moment you are in a supermarket shopping for canned peaches. You are faced with a dizzying array of choices from several manufacturers. If you have not shopped for peaches before you might make a choice based on picture, or label color, or price, or syrup style or some combination of these. The point is that until you make that purchase and eat those peaches you will not know if you actually like them or not.
Now consider three white spruce seedlings ready to plant. They all look the same with single needles and a brown bud at the end of the leader but each one is different from the others. The first seedling came from seed derived from Alberta, the second from wild collected seed originating in Minnesota and the third seedling from improved seed from a Minnesota source. Which one do you buy?
If you plant these three seedlings on an appropriate white spruce site you may have to wait a few seasons before the differences become evident. The non-native Alberta source will struggle because its genes are not adapted to Minnesota. It will be under stress due to spring frost damage and summer temperatures that are too warm for it. These two stress factors will result in slower height and diameter growth and more insect and disease damage. Because of the growth stressors and increased incidence of attack by diseases and pests this non-native source is the most likely to die of all the seedlings.
The seedling derived from native Minnesota seed will be much more in tune to the changes in seasons throughout the year. This seedling is likely to grow well, in fact significantly better than the non-native seedling. It will suffer insect and/or disease attacks but typically only when it is stressed due to drought or extreme climate conditions.
But even white spruce seed collected from anywhere in Minnesota may not be the best seed for your location in Minnesota. Through field testing forest geneticists have learned that as a general rule in the upper Great Lakes region tree seed can be moved north or south about 150 miles without loss of adaptation to local growing conditions. Moreover, we have learned that moving seed east or west is more problematic due to moisture gradients while moving seed to or from areas surrounding large bodies of water like Lake Superior should be avoided because the extreme local climate is very different from anything else in the state.
The third seedling is an improved seedling and it was derived from seed collected from a seed orchard that has been field tested for survival, growth, good form and disease resistance across Minnesota for the past 25 years. Among the three seedlings this one will have the best survival, height and diameter growth and the lowest level of insect and disease attacks.
This improved seedling is the culmination of years of research and the routine re-evaluation of field tests to ensure that seed coming out of these orchards is still superior and still adapted to local growing conditions. In short it is the most tested, most trusted seedling on the market.
So, when it comes time to purchase your seedlings make sure you ask about the origin of the seed and only purchase seedlings that will grow in your location. Local seedlings and improved seedlings are your best options for increased survival, and growth while decreasing the incidence of pests and disease. Non-native seedlings should be avoided – they are a headache waiting to happen. After all, you can buy a different can of peaches every day but it takes years to know if the seedlings you planted will thrive.