Some friends of mine just bought an old house with a huge rhododendron up against the house. It is at least 8 feet high and probably 10 feet wide. I did not dig around and there may be multiple shrubs growing next to each other. What are the chances of moving the rhody successfully? Should it be cut way back before hand? Any particular time of year for moving it?
Fortunately, rhododendrons are very likely to succeed in being transplanted. Most experts recommend fall as the best time to transplant. Spring or late winter is second best.
The real challenge is getting a large enough rootball. A five-to-six foot plant requires a rootball of about 3 feet in diameter.
Step 1- dig a 12-18 inches deep trench around the rootball.
Step 2 – under cut the rootball to sever the roots from the underlying soil. The most important roots are the small feeder roots, not the big old ones. You can use a steel cable with a tractor or you can use a shovel and digging iron and a lot of hard work. The rootball will probably be about 8 – 12 inches deep and 3 feet in diameter.
Step 3 – tilt it on its side and slide a piece of 1/2-inch plywood under the rootball and set the plant upright. Use the plywood to move the plant to its new location. (A tarp works, too, if you can get it underneath the rootball.)
Step 4 – dig a new hole 4 feet in diameter and deep enough so that the rootball is 1 inch higher than the depth of the hole. (Slightly above grade)
Step 5 – water well and mulch around the perimeter of the plant BUT keep the mulch at least 2 inch away from the trunk of the plant.
Newly transplanted plants need some tender care and especially need to be watered regularly, but not over watered.
There were no recommendations to cut the foliage back. But it is always ok to prune out dead, dying, diseased or deranged stems. This also means you can prune out twiggy growth.
This information comes from Success with Rhododendrons and Azaleas by H. Edward Reiley (1992).
My rhodies have black spot, rust. Is there a plant medicine I can put in the soil so it will get absorbed by the entire plant rather than spraying every other leaf.
I am sorry to hear about your sick Rhododendrons. You should take a take a leaf sample into a Master Gardener clinic for (free) diagnosis. I have linked a list of clinics in Snohomish County below. Their volunteers are trained in identifying plant diseases and suggesting solutions.
If you cannot get into a clinic try the HortSense webpage from Washington State University Cooperative Extension, and search the common ailments affecting rhododendrons (in the Ornamental Shrubs section).
The reason why it is vital to get an accurate diagnosis is because some fungal diseases do not have treatments that really work, such as rust, while other “leaf spot problems” are not caused by fungus at all, therefore spraying with fungicides or applying a systemic to the soil would only be a waste of time and money!
Try contacting the Snohomish County Master Gardener Clinics to see if you can bring in samples.
Is it okay to fertilize my rhodies, azaleas, and roses in September? I missed
doing it in August.
Generally speaking, it is best not to fertilize your shrubs after mid-summer. The tender new growth that results is susceptible to frost, disease, and insects just at the time of year when the plant is beginning to shut
down. This is also true of roses, which are even more tender and susceptible than rhododendrons and azaleas.
An article by Terri Richmond (British Columbia) on the American Rhododendron Society website, entitled Fertilizing Rhododendrons the Organic Way supports the practice of fertilizing in spring. (Keep in mind that azaleas are in the same genus as rhododendrons.)
Oregon State University Extension suggests that budbreak in spring is a good time to fertilize roses, just as new growth is beginning. Stop fertilizing in late summer. Oregon State University also weighs in on fertilizing rhododendrons (if needed, in spring shortly after flowering, and preferably with organic fertilizer).
A ten acre public garden on Whidbey Island featuring Rhododendrons and companion plants in a woodland setting. The website includes a calendar of events and a catalog of specialty plants available in the nursery.
Home to one of the largest collections of species rhododendrons in the world, the garden displays over 700 species of rhododendrons and allied plants. Located in Federal Way, the garden is open Tuesday through Sunday year-round.
Make new plants by taking softwood cuttings. Cuttings Through the Year, a booklet published by the Arboretum Foundation(available for sale at the Washington Park Arboretum gift shop) suggests which plants to propagate month by month and how to do it. A few September plants include:
Rock Rose, Salal, Lavender, Holly, Penstemon, evergreen azaleas, Sweet box, Salvia, California Lilac and many others.
For a tutorial on taking softwood cuttings go online to a Fine Gardening article complete with clear color photos: www.finegardening.com/propagate-your-shrubs-softwood-cuttings
You need only take a walk through Washington Park Arboretum or peer into your own backyard to notice that May is the season of the rhododendron. It would seem that rhododendrons are native to the Northwest, the superb way they thrive both in the cultivated garden and wild forest floor. But those rhododendrons, which have become such a mainstay in Pacific Northwest flora, are relative newcomers to these parts and have been plucked by enchanted plant hunters from China and the Himalayas.
Jane Brown tells the dramatic and long history of the rhodies global travels in her recent book, Tales of the Rose Tree: Ravishing Rhododendrons and Their Travels Around the World, (Harper Collins, $36.75). In this accessible historical account, Ms. Brown tells of the legend & lore, as well as the botanical significance, of the rhododendron. She includes many fine illustrations and color plates of many notable representations of the rhododendron. In addition, she lists many of the best places to find rhododendrons, mainly in the UK, where she resides. Travel to the Royal Horticultural Society’s Wisley Garden or the Edinburgh Royal Botanic Garden for grand displays of this woody and lovely plant.
Or remain closer to home and visit The Rhododendron Species Foundation and Botanical Garden in Federal Way. Twenty-two acres encompass nearly 10,000 rhododendrons in all shapes, sizes, colors, and scents. From March through May, the Garden is open from 10:00 – 4:00 six days a week (closed on Thursdays). June through February, the Garden is open 11:00 – 4:00 five days a week (closed Thursdays and Fridays). Admission is $3.50 for adults and $2.50 for seniors and students. For additional information and directions, call: 253-927-6960.