Growing  Vireyas




Vireya Rhododendrons grow in the wild areas of New Guinea, Borneo and throughout the Malay-Indonesian chain of islands.  More and more people are learning to enjoy their brilliant colors year round with the increase of solariums, attached greenhouse rooms, and hobby greenhouses, or outside in frost-free climates.

We have found that these exotic plants are very easy to grow as long as they are not exposed to below-freezing temperatures.  If other houseplants thrive for you, the Vireyas will do equally well.  Dry house air is definitely not desirable.  You can modify dry air by using a humidifier, or by placing bowls of water near the plants.  We think that an indoor table-top fountain is essential for vireyas if you are over-wintering in the home.

Where to grow:

        Outside all year in frost-free areas.

        Outside after the last spring frost and until the first frost.

        Bring into a greenhouse, atrium, enclosed sunroom, etc., before the first frost.

        If only a rare, mild frost, provide temporary protection by covering your plants.

        In a living area, with added humidity from a small table fountain, and light.

        In a greenhouse year round.

Morning sun is desirable with filtered sun and shade in the afternoon.

Growing medium and potting practices: A soil-free, acidic mix is used to simulate the native conditions where these plants are often found on high, moss-covered boughs of trees.  To achieve a loose, well-aerated mix with quick drainage but with water retention abilities, we recommend the following (which we make and use): two parts orchid bark, one part coarse peat, one part perlite and one-half part pumice (if available). If pumice isn’t available increase the amount of perlite used.  Do not use commercial potting mixes.  We do sell potting mix if needed.

Pot size: The plants we ship to you are usually either one, two or three years old and are planted in bands, making a narrow but tall container.  Any older plants would be in a one-gallon pot. We suggest keeping your plants in the containers in which received for at least one year.  In most cases your plants will have been repotted prior to shipment (noted on the instructions included with your order).  Vireyas like the drainage provided by a taller pot and they like to be slightly pot bound.  When you think it is time to repot, we advise not over-potting, that is, not putting it in a much larger pot.  A plant received in a medium band (2 7/8” x 5 ”) should be moved to a tall band.  A tall band (3 5/8” x 6”) should be moved to a gallon size pot and a gallon moved to a two gallon tall.  A restricted root area means that there is less medium to stay soggy after watering.  The sides and bottom of the root ball should be loosened so that the roots will move out into the new potting mix.  For better appearance, and so it will not fall over, place the band or pot inside a larger pot.

Light conditions: When plants are outdoors, direct sun from sunrise to 11 or 12 noon and filtered sun thereafter is ideal.  We have no lack of blooms from our mature plants without the use of supplemental light.  During the colder, darker winter months (Dec-Feb) our plants experience a slow-down in growth, although not a true period of dormancy.  Our major bloom display extends from October through June.  Vireyas come from a 12-hour day area.  They can get along without supplemental light, but would love some if they are not outside or in a greenhouse.

Temperatures: Vireyas will usually not survive freezing temperatures.  Some plants might even get through a light frost but you should not take the chance.  Temporarily cover plants outside or move them inside somewhere.  We keep our vireyas in our greenhouse and plastic houses that are heated when the interior temperatures drop to 42F.  Based on their natural growing conditions, we recommend that it is best to provide a change between day and night temperatures rather than a constant warm temperature.

Pruning: You can encourage bushy plants by pruning and pinching young plants when they are only a few inches high and up to about two or three years old (do as we say, not as we do).  At that point avoid pruning and pinching until after blooming.  Even though flower buds may not be evident, a late pinch might prevent the plant from blooming the next season.  Flower buds often wait for the second or third flush of growth.  The plants ultimate size is naturally an important consideration.  A few varieties can be considered moderately small, like ‘Valentine’.  Most of the yellows with R. laetum, aurigeranum and zoelleri in their background make vigorous upright growth.  The whites, reds and pinks are usually compact, bushy types with some exceptions.  Judicious pruning on older plants will help to keep the taller types within a three to four foot height.  After a branch has bloomed you can prune it back as far as needed to maintain the shape.  To prune large older plants establish a routine of pruning 1/3 of the plant each year, if you want.  Don’t forget to deadhead and do not be afraid to prune.

Disease and Pests: The same practices apply to vireyas as to other rhododendrons. 

        Powdery mildew can be a problem but is easily controlled with any mildew spray.

        If Rust infects other rhododendrons in your garden it may spread to your vireyas.  A general fungicide recommended for roses will normally take care of the problem.  Good sanitation practices are always a smart move.

        Aphids and Scale occasionally appear but are easily controlled using available commercial products, or use your fingers to squish the aphids and rubbing alcohol and your fingernails to kill the scale – easiest method for a minor problem. We have never had mites, but they can be a problem that needs attention.

        Lace Bug is now a problem in the Pacific Northwest.  The plants we ship will have been treated with a systemic control spray. 

        Very rarely die-back” (black stem, dropping leaves) may appear. This is different for the normal darkening of branches.  Immediately prune back to healthy wood, dispose of the diseased parts (not in yard debris recycling or compost piles) and sterilize your pruning shears.  Because these are semi-tropical plants, there is a constant renewal of foliage.  However, if the newer leaves are dropping you may have a problem, usually caused by over-watering or over-fertilizing.

        Phytophera (root rot) fungus is carried through the soil in water and can infect rhododendrons if drainage is poor or if pots are over-watered or sitting on contaminated ground.  If you scratch the bark at the base of the trunk and you find brown, not green tissue it is Phytophera.  A plant dying from Phytophera can not be saved and should be discarded in the trash (plant and soil), not in yard debris for recycling or in the compost pile.  Pots should be treated with one part Clorox to ten parts water.



Feeding: We have two methods, either fertilizing with a soluble fertilizer such as Peters 20-20-20 at strength (never full strength) at each watering or, using Bovees fertilizer when the plant is at least one year old and has a well-developed root system. 

Our fertilizer has a low rate of slow-release nitrogen, plus super-phosphate, dolomite limestone, iron chelate and trace elements.  The organic nitrogen base is from canola and alfalfa meal.  We like our fertilizer because it never burns, if used as directed.  We recommend using our fertilizer every three or four months – a level teaspoon for one or two year old plants and a rounded teaspoon for three year plants in a tall band pot.  One tablespoon to a one gallon pot.  Water immediately after fertilizing to prevent surface caking.  Do not allow the fertilizer to sit in a lump against the stem.  A harmless gray mold will appear in the first two weeks but disappears after watering.  A small supply of our fertilizer is included with your order,

If you have foliage turning brown along the edges you may have used too much or too strong a fertilizer.  Use lots of water to leach the fertilizer out of the soil.  A white crusty buildup around the top inside of the pot also indicates too much fertilizer or insufficient leaching of fertilizer salts.

Watering Practices: Avoid a continually soggy potting mix.  As a general rule, water thoroughly, and then withhold water until the pot feels light, before watering again.  If your tap water is bad, use rainwater when possible.  Tall pots drain more rapidly than a shallow pot.  Always water from the top until it runs out the bottom.  Do not let your plants sit in water.  It is hard to resist the urge to water your plants.  BUT PLEASE, learn to lift them and only water when they feel light.


Don’t KEEP your plant dry – just let it BECOME lightweight and then water thoroughly.