Services for Greenhouse and Nursery Growers

Testing Strategies

Monitoring and preventing nutrient imbalances is much more desirable than trying to diagnose and remedy a problem situation. Analysis of the soil-less mix gives a general overview of the nutrients available to the plants and serves as a good first assessment of potential problems. The plant tissue analysis is best for monitoring the micronutrient status as well as pinpointing sources of nutrient problems if they do occur.

Soil-less Media Testing

Soil-less Mixes

Samples may be submitted directly to the lab or through the county Extension office. At least 1 quart of media is required for this analysis.  Soluble salts, pH, phosphorus, potassium, calcium, magnesium, and nitrates will be determined on a saturated water extract of the media. The results, which include interpretation guidelines for both bark-based and peat-based mixes, will be mailed to you. The fee is $10.00 per sample.  The results will be returned to you by mail.

Plant Tissue Analysis

Benefits of Tissue Analysis

Routine plant tissue sampling and analysis can be used to establish a 'baseline' of nutrient readings for reference if future problems occur. The analysis results can be used as a fertilizer management guide for perennial plants or the results can be used to diagnose nutrient problems with both perennial and annual plants.

Sampling Information

The values obtained from the tissue analysis are particularly dependent on the plant age and plant part sampled. This is important to consider when comparisons are to be made with established nutrient sufficiency ranges. For problem solving, collect samples from problem areas and a separate sample from the problem-free area for comparison if you do not have the 'baseline' data mentioned earlier. As a general rule, sample the most recently matured leaves early in the day.  About 2 cups volume of leaves is needed for a complete mineral analysis.  Be sure the leaf surfaces are free of excess dust and residue from chemicals.  If you are uncertain, rinse the leaves in distilled water and allow to air dry before submitting to the lab or the county Extension office using a paper bag.  Contact the lab or your local county Extension office for information regarding correct sampling procedures for the particular type of plant you want analyzed.

Analysis Results

The analysis report, which will be returned to you by mail or email, will contain your analytical results and the specific nutrient sufficiency ranges for most types of plants submitted. Sufficiency ranges, however, have not been established for many non-commercial types of plants.  Comparing the results from a healthy sample with the results from an unhealthy sample is helpful in situations where ranges are not available or cannot be used. Your Extension agent will help you interpret your results.


Irrigation Water Analysis

Benefits of Irrigation Water Analysis

Irrigation water can be tested where a problem with salinity is suspected. Growers who suspect that a specific element may be causing a toxicity problem due to excessive levels can also benefit from an irrigation water analysis.  All new water sources should be tested prior to use to prevent potential water quality problems and determine suitability. This service is not intended for assessing water for drinking purposes.

Analysis Results

The analysis report will be returned to you by mail or email. The lab or county Extension office will provide you with sampling guidelines and assistance for interpretation of the results.