You don't say where you live, but the fall is the best time when there is plenty of moisture in the soil and the weather isn't too hot. Usually late September or October is ideal since it is cooler. Then water during weeks that have less than an inch of rain the first year when the ground isn't frozen. Don't over water, but don't let it dry out. The roots will be a little compromised for a while.

Plant slightly higher than it is now, never deeper.

Mulch well. Your main problem will be frost heave, so keep it mulched and watch whenever you have a thaw to see that it is OK.

Here is a link that might be useful: How to Grow Rhododendrons and Azaleas

Rhodyman, I appreciate the information. I'm sorry I didn't get back to you sooner with my thanks.

I checked out the link. I have 7 or 8 rhodos and all have been healthy. All look beautiful when in bloom----all except one. It is a dwarf one (I think it was called Northern Sunburst but not quite sure) and it has never bloomed. Since I planted it many years ago it's been healthy and gets new new leaf growth every year but no flowers--it never gets those little fat flower buds,only the leaf ones. After reading the info I think that my plant may be TOO healthy so I'm going to try the suggestion given by Henning--- moving and/or pruning it.

I am so glad you included the link.

~Geraldine

There are several things that will prevent flower bud formation:

1) not enough sun light in the summer. Either prune the shade back or move to more light.
2) too much nitrogen. Never use chemical fertilizer, you can use Hollytone once it starts blooming, but at half the rate on the package.
3) not enough phosphorus. You can use superphosphate, but it is very slow acting. Don't use too much, wait a couple years.
4) pruning in summer or fall or winter. Only prune right after bloom.

Don't prune now. If you have any buds, you will loose them. If you don't it won't help now. Prune right after bloom time.

It may be Northern Starburst, a tetraploid PJM. It blooms very early and may be having its flower buds frozen back when they start to open. Most PJM's tolerate a fair amount of shade so that may not be the problem. It may be too much nitrogen and not enough phosphorus.

Here is a link that might be useful: How to Grow Rhododendrons and Azaleas

Rhodyman, I always thought the problem might be too much shade. A couple of years ago, I cut back a plant that was near to the rhodo. I still didn't get blooms these past 2 years and now the plant-----I think it's centaurea(sp?)---- is just as big as before. I may move the NS rhodo to a new area within the next couple of weeks.

Thank you for the help.

~Geraldine

Tyler Arboretum has the premier Dexter rhododendron collection in the Philadelphia area as well as many species including R. maximum. They had a massive renewal program and moved many very large plants that Dr. Wister planted many decades ago. They found their best method of moving healthy plants that had partial sun was to cut them way back to a couple feet and then let them grow back after they were moved. That worked exceptionally well on plants that were not in complete shade before they were moved.

The Rhododendron Species foundation near Olympia, Washington, found themselves in a big pickle. They had planted all their plants in a soil mix with lots of sawdust which was supplied in unlimited quantities from Weyerhauser. However, when the sawdust started decomposing, the soul became an oatmeal like substance that did not drain well. They had a big risk of Phytopthera and plants dying. They started a major project of digging all plants up and replanting them. They didn't cut them back. I saw several tree size rhododendrons that they had dug and the roots were sandwiched between two shipping pallets. They removed as much soil as possible without disturbing the fine roots. They were very successful.

One of the techniques that is necessary is to root prune in a circle around the area where you intend to dig in advance. This gives the plant a chance to form a dense root mass closer to the trunk. It is essential that the plant be healthy before it is moved if it is expected to be healthy after it is moved. As they found at Tyler, open up the shade above plants before they are moved. This will give them a boost and make dormant buds move viable.

Cheers, Steve Henning in Reading, PA USA Zone 6

Visit my Rhododendron and Azalea web pages at:
http://rhodyman.net/rasite.html

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http://rhodyman.net/rabooks.html

Here is a link that might be useful: How to Grow Rhododendrons and Azaleas