Perry Laboratory


Advising and Testing for Nurseries

In nursery production, the most intensive horticulture is practiced to grow plants for all or part of them, generally for sale. The use of laboratory testing helps in making the best management decisions.

Nurseries - Root Bound

Many nurseries utilize routine laboratory testing to help track how their fertility levels are reacting to the management at the nursery. Routine regular testing gives an indication of whether the soil acidity is increasing or decreasing. The concentration of soluble salts can help determine whether the irrigation practices are providing sufficient leaching to avoid an excessive accumulation of soluble salts. Routine soil testing helps determine if the fertility levels are satisfactory for the crops being grown. This in turn reveals if the fertilizer program is operating properly. A fertilizer program entails the proper fertilizer materials being used at the correct rate of application in a uniform manner. These areas are addressed in a routine testing program. When plants are in a deficient or excessive growing system, they are often affected, however do not show the symptoms immediately. When the problem is identified early enough, it can be corrected and the symptoms may not show in the plants. Problems can occur from many areas, including the use of wrong fertilizer materials, equipment failure or personnel mistakes.

Nurseries - Pointsettas

For container nurseries, generally it is best to monitor the fertility and physical properties of the potting media that the plants are grown in. This testing monitors the consistency of the mix components, along with the uniformity of the mixing process. This data becomes the “baseline” levels that the plants will initially grow in. From this point, the routine testing will follow the effects of the cultural management practices to determine if adjustments should be made. This is particularly important for Holiday crops that are grown to be ready for sale at a set date or period, where there will be less time for adjustments to be implemented.

Irrigation water testing is also very important for nursery production. The raw irrigation water may require treatment, such as acidification, in order to provide the best water for irrigating the crops being grown. Testing of the fertilizer solutions used at the nursery determines if the fertilizer materials are correct and being measured accurately and dispensed at the proper rates.


The use of plant tissue analysis determines the actual nutrient levels within the plants and can indicate possible imbalances with nutrients in the media and also the growth activity of the root system of the plants. This information can help in determining if there may be problems in nutrient uptake, unavailability of nutrients or possibly environmental problems.

Guidelines for Tissue Sampling in Various Crops

Cut Flowers and Nursery Crops
Crop Number of Leaves Plant Part (leaf) Time of Year
Roses 25-30 Uppermost five-leaflet from a flowering shoot just showing color. None specified
Carnations 30-50 5th and 6th pairs from non-flowering shoots. None specified
Chrysanthemums 25 4th leaf from tip Bud start to finish
Alstroemeria 20 First fully developed None specified
Azaleas 50 Most recently matured None specified
Gypsophila 50 Most recently fully developed None specified
Cyclamen 15 Top 50 days after transplant
Gardenias 25 Most recently matured None specified
Geraniums 15 Most recently matured None specified
Gerbera 15 Most recently matured None specified
Hydrangeas 15 Most recently matured None specified
Kalanchoe 15 4th leaf from tip None specified
Lily, Easter 15 Most recently matured None specified
Poinsettias 15 Most recently matured None specified
Snapdragons 25 Most recently matured None specified

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Fruit and Nut Crops
Crop Number of Leaves Plant Part (leaf) Time of Year
Apples 50 Mid shoot current growth Mid-season
Apricots 50 Mid shoot of current growth Mid-season
Avocado 50 Most recently fully expanded non-fruiting terminals Leaves 5-7 months old
Cherry, sweet 50 Midshoot current growth July-August
Grapes, wine 30-50 Petioles opposite basal cluster Full bloom
Olive 50 Mature leaves from middle of non-bearing, current season shoot Late June through early August
Peach 25 Leaves from midshoot current seasons growth flower clusters Mid-summer
Pear 50 Leaves from midshoot current growth Mid-summer
Raspberries 50 Most recently matured leaves Flower bud start
Strawberries 25 Leaves and petioles, most recently matured At flowering
Conifers 25 2-3” terminal cuttings Summer

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Perry Laboratory - Serving Horticultural Industries since 1938