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Top Ten Recommendations for Rhododendron Survival

Once your plant is delivered, we can no longer provide care of the plant and the survival of the plant is up to you.  Please find below the top ten suggestions for plant survival.  This is simply a guide for the best care of your plant.  We cannot give you a one size fits all guide, because a plant growing in Washington State and a plant growing in North Carolina will have different environments and will need different care.  The American Rhododendron Society ( lists more tips as well as a directory of local chapters that have local members that are usually willing to help answer local questions. 

1 – Rhododendrons need well-draining soil.  Rhododendrons need to have their roots moist but not wet.  To determine if your soil is well draining, dig a hole that is 12 inches deep where you will plant your rhododendron.  Fill this hole to the top with water.  If the water remains in the hole for more than an hour, your soil does not drain well.  In this case, consider planting your rhododendron on a mound.  Refer to planting tips at

2 – Plant your rhododendron at the correct height.  The root ball of your plant needs to be at the top of the soil level.  A properly planted rhododendron will have a single stem emerging from the soil and visible outlines of the of the root ball right at soil level.

3 – Make sure your plant is getting plenty of water.  Newly planted shrubs will not have the same root resources for several years as the established plants in your yard.  Please do not assume that your current irrigation system that is tending to your established plants will be enough for your new plants.  Running water directly to the root ball of your new plants will help get the water needed.  Establishing rhododendrons need to have moist, but not wet roots.  The best way to test if your plant is getting enough water is by sticking your finger into the soil near the roots and seeing if the soil is moist. 

4 – Generally speaking, rhododendrons do not like the heat and/or too much sun.  Rhododendrons also cannot tolerate too much shade.  When you are determining where you will be planting your rhododendron, pick a spot that will receive 3 to 8 hours of direct or filtered sunlight.  In general, rhododendrons with smaller leaves tolerate the sun more than the larger leaf varieties.  Yellow and Orange blooming rhododendrons tend not to be as sun tolerant as some of the darker blooming rhododendrons and will do better in 2 to 6 hours of direct or filtered sun.   When selecting a plant site, take into account landscaping material or surrounding structures that will hold heat(such as concrete, landscape stone, brick foundation).  This heat need to be taking into account for additional exposure to heat.

5 – We all want our plants to have the best start as they are planted.  However too many soil additives at the time of planting can shock or stun the plant.  Unless you have had your soil tested, do not add any acid boosters to the soil at the time of planting.  If your soil is low acid, add the boosters to the soil and have the soil retested before planting.  Plant into existing soil or soil with natural composts added.  Adding a slow release fertilizer as a top dressing is OK.  The goal is to not shock the plants as they are growing in their new environment.

6 – Root ball manipulation is not needed when planting new plants.  We have transplanted over a million rhododendrons and have found in all cases, scoring or disturbing of the root ball does not benefit the plant.  If you plant during the growing season, when the plant is out of dormancy, new moist soil pressing on the edges of the root ball will stimulate fine root growth in just a few weeks. 

7 – Rhododendrons will need a regular supply of water.  Planting rhododendrons under a canopy of trees makes for a beautiful landscape, however the rhododendron will compete with the water resource of the tree roots.  When planting under trees or in densely planted areas, consider planting your rhododendron on a mound over the root population.  This will allow your rhododendron roots to establish above the tree roots.  Weeds also compete for water.  Keeping the planting areas clear of weeds will allow your rhododendrons to establish wider roots faster. 

8 – Purchasing the proper plant for the proper climate zone.  Not all rhododendrons are hardy to the same cold temperatures.  We give specific hardiness temperatures for the plants.  If a plant is rated Hardy to -10F, it will probably not thrive in an area where the temperatures get below -10F. There are some enthusiasts that push the boundaries on temperatures, but for the average landscaper, making sure the plants you purchase are hardy for your area is very important.

9 – Proper soil conditions are important to have your rhododendrons thrive.  Visually, we cannot always tell what is going on with the soil just by site.  Local extension offices may be able to do a limited amount of soil testing for you that can help.  There are a couple of situations that would warrant not planting rhododendrons unless you have your soil tested specifically for these conditions.  Rhododendrons want acidic soil.  Many new construction site where new concrete is poured or there is construction waste (such as plaster or drywall) in the soil will make the soil be very basic (opposite of acidic).  Bringing in new soil is highly recommended for newly constructed planting beds.  If you have poor draining soil with sitting water, or have had a rhododendron or other woody shrub instantly die, there may be fungus in the soil.  Soil fungus is very difficult to control because it spreads by water.  Our recommendation is to select a fungus tolerant shrub rather than a rhododendron for this area. 

10 – Container planting can be done with rhododendrons, however, it will take special care.  There is an article about container growing on our website.  In a sentence, your rhododendrons in containers will need more water and regular slow release fertilizer than a rhododendron planted in the ground. 

There are hundreds of books written about the care of rhododendrons, and to try to sum it all up in ten areas is simply not possible.  With the magic of the internet, there are so many resources out there to reference.  Again, the best place to start is with the American Rhododendron Society and work out from there.