Unpacking Instructions:   Unpack your azalea order immediately upon delivery.  Always protect plants from freezing and overheating conditions.    Dormant azaleas are shipped without a pot and should be potted up and watered upon arrival.  If the plants are not to be forced immediately, place the potted plants in a refrigerated cooler (34-40 degrees) or in a cool house.  The azaleas have adequate levels of fertility remaining in the root ball from the growing cycle so no additional fertilizer should be needed during holding or forcing.

Holding Instructions:  Azaleas placed in a cooler at 34 degrees will hold their dormancy.  Be sure plant foliage is not wet when plants are placed in the cooler.  Adequate ventilation is needed to avoid development of several fungal pathogens,  such as Botrytis spp.  Keep the relative humidity high (>90 %) so the plants do not dry out too quickly.  Check the moisture content of the root balls weekly and water as necessary.  Never use overhead watering.

The length of time a plant can be held dormant, depends upon the physiological condition of the plant when it is placed in the refrigerated cooler or cool house.  Once a plant's cooling requirements are met, the longer it is held dormant, the shorter the time required to force into color.  Pre-cooled plants of the same variety will take 5-6 weeks to force in November, but only 3-4 weeks if held in a cooler and then forced in February.

Many factors affect how long a plant can be kept in a cooler.  Individual experience, with different varieties under the specific conditions of your facilities, will help you determine the ideal conditions for holding and forcing azaleas at your location.

Forcing Instructions:  Once the cooling requirements of a variety have been met, dormancy can be broken and the plant forced into flower.  If azaleas are put in a greenhouse for immediate forcing, keep them at 55 degrees for the first week before raising the temperature.  Optimum forcing temperature is 62-65 degrees.  Never take azaleas from a cool environment (34-35 degrees) and place directly into high temperature areas (>90 degrees).  Foliage burn and/or reduced flower quality can result.

Do not use overhead watering systems when forcing azaleas.  The plant branches tend to "open up" leaving open areas in the center of the plant.  We recommend hand watering at the soil level, drip irrigation, or a capillary system such as flood floor, flood trough, or capillary mat.

The length of the forcing period will vary according to the plant variety, the length of the pre-cooling period received, greenhouse bench temperature and light intensity.  Extended day length and/or higher light intensities during forcing, particularly in winter months, will shorten the forcing period.  This is particularly common in the more northern states of the U.S.

Vogel varieties are recommended for Christmas.  It will generally take 3-4 weeks to bring these varieties into color.  Non-Vogel varieties typically require 5-6 weeks forcing time.

Spring/Summer 

Woodburn Nursery & Azaleas, Inc. would like to advise customers forcing dormant florist azaleas of two spray programs that should be followed to help ensure the optimum flower development and quality from May through September.

The first is spraying flower buds with gibberellic acid (GA), which we feel is beneficial in helping produce uniform flower bud development and, in some varieties, shortening forcing time on the bench.

There are several formulations of GA on the market. We use ProGribb 4% at a rate of 1-2 oz/gallon. Spray one application of 1-2 oz/gallon within one week of setting plants on the greenhouse bench. If a oz/gallon application rate is used, a second application of 1 oz/gallon should be applied one week later. Wet leaves and buds uniformly with each application to ensure good coverage. If another formulation of GA is used, adjust the application rate so that the same concentration of active ingredient is applied. Be sure to follow all the manufacturer’s recommendations/limitations on the label.

As warmer weather approaches, thrip damage on dormant florist azalea buds can become a problem before symptoms are noticed. This insect is highly mobile and can easily travel from other infected crops from either within or outside of your forcing facility. Thrip damage is generally not noticed until flower buds start showing color. Thrips can be detected by shaking or tapping a partially to fully opened flower onto a sheet of white paper. Small, tan-to-dark colored dots (thrips) can be seen rapidly moving around on the paper. Damage to the flower margins might first appear as brown edges or streaks on the developing flowers, or in more severe cases, as dried brown flowers and petals.

A preventative thrip spray is the second program we advise developing. Check with your local chemical supply company for registered chemicals approved in your area for preventative treatment of thrips on azaleas. Always read labels carefully before application.

If you have any questions, please feel free to call Woodburn Nursery & Azaleas, Inc. at 503-634-2231. We value your business and thank-you for purchasing your dormant florist azaleas from our company.