You will love Capistrano until it gets root rot and dies. It is a very popular plant but is not long lived in most gardens. If planted with care in a raised bed with good drainage and good mulch, you may be able to get it to survive.

The other are great plants. My favorite white is Boule de Neige. It is the only true white (not from faded pink buds) and has super shiny dark green foliage. A true gem that is super hardy, heat and sun tolerant, and not too tall.

Regarding Vulcan's Flame, Henry's Red and Nova Zembla are much hardier, but Vulcan't Flame is a little nicer plant and flower.

Good Luck!

Here is a link that might be useful: How to grow rhododendrons and azaleas.

rhodyman - Thank you so much for responding to my post. I think I have good conditions for Rhododendrons. I am in sandy soil within a scrub oak/pine forest, so my soil is slightly acidic and well-draining. My problem is always nutrients, but I find with compost, I haven't had problem growing most garden staples. There are huge healthy rhododendrons all around my neighborhood, so I am hopeful.

I saw the Capistrano at a nursery today and it was just beautiful, so I think I will try my luck and cross my fingers.

For the white, I am actually looking for a very large white as a background. It will be right up against the woodland with plenty of room to grow up and out. That is why I chose Cat. Album.

Do you think Vulcan's Red would do well in a 6b climate? It would be fairly well-protected with trees on three sides. I saw it today as well and thought it was gorgeous.

I know I would have stronger color choices with azaleas, but winter interest is very important to me. I love the idea of some large green-leafed plants as a backdrop for some small-leafed bronze-purple rhododendrons. I'm hoping to get that effect with the Purple gem and Landmark. Are there better plants for this effect, that I should be looking for?

Thanks for your information! I'm so new to this, but am very excited about my new garden bed. Thanks again!

Lisa

I grow all the plants you've listed and agree with everything rhodyman wrote. I'd add only that Olga grows quite large and if you have limited space Little Olga (recently renamed I think) may be a better choice. Vulcan and Vulcan's Flame are nearly identical and no other rhododendron I'm aware of has anything like their brick red flowers. I have found them more prone to winter burn than many, so some form of wind protection may be advisable even in Zone6b. Boule de Neige is a great white if somewhat prone to lace bug damage. It is, however, a slow, compact grower. I like Wynterset White a great deal and I think it would probably be a better choice for a background plant. There's nothing at all wrong with Cat Album, either. I'm not a huge fan of Purple Gem. It tends to be a bit overused and the bronze winter leaf color always suggests drought or disease to me. The flower color is not what I would call near blue - it's a definite violet. Trickier to grow (it's prone to bark split on the sunny side in winter and the leaves look very distressed during that season) is Blue Baron from Weston Nursery in Hopkinton, MA. Not really blue, either, but much closer to it than Purple Gem. Karin Seleger is another low growing early lavender purple that to me has more vividly colored flowers and nicer leaves.

Hello All,
Up until now I've confined my posting to the Pond and Aquatics page but I have a couple of questions for anyone with Rhododendron knowledge...
I have two Cat Album Rhododendrons planted near the top of my berm. There is a lot of tree canopy overhead that pretty much keeps sun off the plants until late afternoon & evening, then it gets a good hit of sun. When I made the earth berm I used what was pretty much typical farmland soil from the area, eastern KS. Usually our soil is slightly alkaline but since my Cat Albums haven't been growing much or flowering at all, I decided to have the soil tested. I found that the soil I put the plants in was slightly acidic, that was a real surprise. But they still aren't flowering or growing much. I water them daily because I heard they are shallow rooted. I don't soak them and the only time they get soaked is when we have a giant thunderstorm but they never really set in water because of the berm. What more can I do to help them grow and flower? The plants are now 2+ years old and I haven't seen a flower since they came from the nursery.

You are having to water them daily, pondbucket? Wow! Watch out for root rot problems if you water so often. While their roots are shallow, you c-a-n wait to water again until the soil feels almost dry or dry to the touch. Insert a finger to a depth of 3-4" and water if it feels almost dry. Otherwise let it be. The 3-4 inches of mulch that you use around them should decompose, become a source of food and lengthen your watering times.

In this berm set up, it is possible that lack of sunlight is causing the plants to not flower as much as they could. Also, flower buds begin to develop on or after July so do not prune or fertilize on/after July so sudden Fall cold temps will not kill the buds.

Luis

I agree, no rhododendron that is planted properly should have to be watered every day. The medium should have some peat in it to hold water and a mulch on top to keep it from drying out. People also use perlite or vermiculite in their media to make it more airy. Rhododendrons need air to reach their roots. If you water too much or have too heavy a soil, air doesn't reach the roots and they don't thrive.

Actually many nurseries do use a medium high in bark dust that dries so fast that they do water everyday. They are doing this to keep from getting root rot. When planting one of these plants you need to open up the roots and back fill with a mixture of real soil amended with peat moss and then mulch thoroughly.

Here is a link that might be useful: How to grow rhododendrons and azaleas.

Thanks.
I guess I should've added that we are very hot and humid here in the summer months and that it is mainly in those times that I water them daily. I have them mulched with hardwood tree mulch. Most everything else grows well on my giant berm area. My hydrangeas nearby were a little slow to get going but now they're doing fine.
I will keep in mind that they flower later in the summer, so I'm holding out hope.
I did visit the Rhodo page and I see that maybe I selected the wrong Rhodo for our midwest heat... I read where the Cat Album likes a cooler climate (that's not us!).
I thought I planted them with plenty of amended soil mix into the hole. If I recall I amended with composted yard waste; my compost is derived from mainly leaves and grass clippings. At the time I was against the use of Peat as I have read were we are depleting the source or at least "not helping" the environment with our steady use of peat moss. But I'm sure that's another topic for another time.

So If the two Cat Album Rhododendrons don't flower this summer should I transplant and try again, or, should I change out the variety?

I would like to address several of your comments as they affect rhododendrons.

Pondbucket: "I guess I should've added that we are very hot and humid here in the summer months and that it is mainly in those times that I water them daily."

The hot humid months are when rhododendrons are most likely to die of root rot. It is best to not water unless the new leaves are limp in the morning. They will always be limp in the heat of the day. That is normal. Do not let that bother you.

Pondbucket: "I have them mulched with hardwood tree mulch."

I did that for a while. When the hardwood mulch decomposes it gets artillery fungus and also depletes nitrogen from the soil. In now only use pine bark mulch.

Pondbucket: "Most everything else grows well on my giant berm area. My hydrangeas nearby were a little slow to get going but now they're doing fine."

Two concerns.

1) Hydrangeas thrive with aluminum sulfate. It kills rhododendrons. While hydrangeas need acidity and aluminum to be blue, rhododendrons are slowly killed by a buildup of aluminum in the soil.

2) Hydrangeas thrive in moist areas. Mine are planted in a bog and love it. Rhododendrons die in moist areas, they need EXCELLENT drainage.

Thanks for all of your wonderful help.

"The hot humid months are when rhododendrons are most likely to die of root rot. It is best to not water unless the new leaves are limp in the morning. They will always be limp in the heat of the day. That is normal. Do not let that bother you."

Okay. I'll try not to let it bother me. Thanks for the tip on identifying leaves for stress.

"I did that for a while. When the hardwood mulch decomposes it gets artillery fungus and also depletes nitrogen from the soil. In now only use pine bark mulch."

So, you think I need to change to a different mulch. I suppose I can do this right below the plant but not throughout the yard, there's just too much of it.
It is interesting what you say though. I had a Blue Spruce near where I have the Rhododendrons and the Blue Spruce died last summer, late last summer, from what appeared to be a fungus. I wonder if this artiillery fungus. It was definitely a fungus.

"1) Hydrangeas thrive with aluminum sulfate. It kills rhododendrons. While hydrangeas need acidity and aluminum to be blue, rhododendrons are slowly killed by a buildup of aluminum in the soil."

"2) Hydrangeas thrive in moist areas. Mine are planted in a bog and love it. Rhododendrons die in moist areas, they need EXCELLENT drainage."

Well, I hope I have the skill to keep this going and water the Rhododendrons less than the Hydrangeas. I have them grouped about ten feet apart. I have never added aluminum sulfate to the soil. I have added acidfying soil conditioner this spring.

Ultimately, I think I will need to replant the Cat Album Rhododendrons or replace them all together. Any other helpful tips to creating fantastic Rhododendrons in our hot/humid climate (zone 5-6), near Kansas City.

What type would you select to plant here? I would like to plant azaleas too.

Rhododendrons are proving to be the hardest plant for me. They like excellent drainage so I put them on a berm, but they don't like winter wind so elevating them is not so good. I don't have any azaleas planted but I once tried those too, and failed! I thought it was either because of our naturally alkaline soil (pH tends to be around 7 - 8) but it could also have been too much peat or too deep or too/not enough water... this is tough. The local nurseries and home depot are supposed to pay attention to our vicinity/climate but they sell Cat Album Rhodos fresh out of the greenhouses when there's little chance for them to flourish here.

I should add, not everything in my garden dies. I actually have a stellar garden going with very little work to do. But the plants I've mentioned, rhododendrons, azaleas, and a single blue spruce, have made me pause with concern.

The artillery fungus does not harm plants, but it shoots black tar balls that stick to fences, house siding, and anything else within a couple yards. I had a white picket fence that was starting to get disfigured. I put the pine bark mulch directly on top of the shredded hardwood mulch. I never used the shredded hardwood mulch near my rhododendrons. They have always been mulched with pine bark nuggets.

If the leaves of your rhododendrons become uniformly light green, then that is the sign of a nitrogen deficiency which is what the hardwood mulch can cause. It is best to not use too much nitrogen since it stimulated growth at the expense of flowers.

However, if the leaves become yellow between green veins, then they are showing an iron problem which is usually caused by the pH being too high. Sulfur is the best way to lower pH. My website has a chart on how much sulfur to use.