Next year’s nutrient management program begins by taking foliar and soil samples now

Taking soil and foliar samples this fall can help you adjust your nutrient management program in your Christmas tree farm for the next growing season.

Foliar sampling can also be used as a tool for fine-tuning your nutrient management program. It compliments soil testing by reflecting what the tree has actually picked up from available nutrients in the soil. Foliar tests can also indicate a problem before visual symptoms, such as yellowing or reduced growth, is evident. We recommend using foliar analysis along with a soil test in the fall to optimize the following season nutrient management program in Christmas tree farms.

Yellowing and poor growth
Yellowing and poor growth in Fraser fir due to high soil pH.

When to sample

Studies indicate that there is considerable variation in plant nutrient concentrations depending on the time of year. Ideally, you want to collect samples when the nutrient concentrations in the foliage are relatively stable. For Christmas trees grown in Michigan, Michigan State University Extension recommends that samples be collected in late fall – mid-October through December.

How to collect samples

In addition to seasonal variation in tissue nutrient concentrations, variations also exist with respect to age as well as location of the tissue being sampled. It is recommend that you collect 2 to 3 oz. of needles from the current growing season growth taken from the upper 1/3 of the crown of the tree (staying away from the leader). If you are seeing a problem in your field such as off color or poor growth, make sure to collect separate “good” and “bad” samples to potentially help diagnose a nutrient deficiency problem.

Keep the samples cold and dry and mail them to the MSU Soil and Plant Nutrient Laboratory as soon as possible after they have been collected. Assign a sample name/number so you can keep track of the fields and take detailed notes if you are seeing problems.

Videos on foliar sampling and how to take a sample are available at the MSU Christmas Tree Team website.

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