So how much space did you allocate for each? Paniculatas typically have little winter dieback here so I would allocate 6' minimum if given an estimate of 5-6' and I might prune depending on how quickly they grow back to their previous height/width that they had when I pruned.

Sine you have little cold weather and your growing season is long, be ready to prune. ;o)

White Diamond has room to grow. It's Fire Light which has only about two feet on each side. On one side is a very young Fothergilla and on the other side, Itea Merlot. Both can take a little crowding, I suppose, but I don't want to crowd the Fothergilla, They grow slowly and I consider it one of the special plants in my garden. Might have to do something, though I don't know what. This is Fire Light below.

It seems Fire Light may grow larger than White Diamond. Is that right? Perhaps I ought to switch them around. .

This is White Diamond.

They are both planted in partial shade.

I think they re very similar width wise. And sorry for asking the obvious to you, why not transplant one of them? This will not be the first or last time that a newly planted hydrangea had to be transplanted. Is it because there is no other location or ??? reason? By the way, WD looks like it needs some water (some of the leaves near the top look wilted).

Look to see if you can find another location where you do not have to prune them. It will be one less thing in the list of things to do in the Fall or Winter-ish...

Not knowing the sizes of all the other shrubbery near these two, I am going to throw a wild suggestion... convert them into tree form hydrangea paniculatas. In a tree form hydrangea, only one stem is left growing up, usually the straightest one and then all bloomage originates from that one stem, several feet up in the air. May be too complicated but it lets you have shorter shrubbery under these guys too.

Thanks for the thoughtful advice. My biggest problem is a small garden and an addiction to collecting plants. I simply don't seem to be able to resist a new plant that catches my eye. It wouldn't be so bad, except that my garden is pretty much planted out.

Our garden club meeting six or seven weeks ago was at a new nursery and I spotted White Diamond with its gorgeous white flowers and I just couldn't resist. To fit it in, I had to dig out a Japanese Maple that wasn't putting on enough of a show. Unfortunately, WD has suffered from a series of 95F days when I forgot to give the extra water a newly planted plants needs. I think/hope it will recover.

Last week at our local nursery I spotted Fire Light. It has the prettiest leaves! Another irresistible plant! I moved a Ribes to the native section of my garden where I won't mind its summer dormancy period. I really don't have any other options for relocating Fire Light.

To give you an idea of the scope of my problem, I've got a Hydrangea quercifolia Munchkin sitting in a pot and I don't know where to plant it. I've got another dwarf HQ in the ground and it's crowding a beautiful dwarf conifer and one of them will have to be moved this winter and I don't know what will be sacrificed so that I can keep both of them.

H. paniculata varies quite a bit in size depending which cultivar. I have White Diamond, but it hasn't yet reached its full size, so I can't help beyond the published size, though it does seem to be fulfilling its published tendency to be wider than tall. Published info suggests a similar width for the two cultivars, with WD shorter than Fire Light. From everything I have seen of many cultivars of H. paniculata, it is quite difficult to control height by pruning since from a late winter hard pruning such as down to 2'-3' from 6'-8', most established H. paniculata types can regrow almost all of that in a single season, at least in this part of the country. You can't reprune during the growing season without losing the flowers, and I am not sure when you would need to prune to avoid removing flower buds in your area. I don't know if one can prune to create a narrower tall shrub shape more successfully than for height. One option might be to train the 'Fire Light' to "tree" form if there is more width higher up. I don't think that is too likely to work for the WD since it is one of the shorter Hydrangeas.

The H. quercifolias are also large plants . . . do you have a neighbor who would appreciate a shrub border in a spot where you could see it?

I was thinking the same as Luis: even if you don't do "tree form" you can leave a few stems and keep removing the lowest branches so the plant grows more upward than outward. I see a lot of really old PGs that grew that way, and they are very pretty. I picked Strawberry Sundae and Bobo for my small plot of land since they are pretty, but much smaller (3x3 if I recall). I also have a Little Lime in a pot, which I think could get a bit bigger.

You can be like me and just add more plants in containers :-) I have very little real estate to garden in to begin with and I have managed to fill all that and then some! But I do have a very strong plant acquisition urge so all new plants are pretty much relegated to being grown in a container.

The problem now is that I have so many containers that I am running out of room for them as well. Very frustrating, as I have several plants - actually trees - on my want list that I will have to find room for.

Nice to know that I'm not the only one with plant acquisition disease..... I just sold eight Blueberry shrubs in 25 gallon containers. They were all "planted" against the fence along my long driveway (I live on a flag lot) and getting too big and needing repotting. The driveway looks way too naked now so I'm sure I will spread out again into the driveway, but for now I'm really trying to keep my containers to a minimum as they are a lot of extra work to water and repot.

I'm going to just let the Hydrangeas grow and see what they want to do. I think White Diamond will be fine in its location. Fire Light is in the more problematic spot and downstream I might have to decide between keeping the Itea on its right or keeping the Hydrangea because I'm not really enthusiastic about converting to tree form. I was heartened upon reading this:

"If you do not have a 6' x 6' area available for Fire Light Hydrangea to reach its full potential, you can train it to a more compact size with moderate pruning. They are very well behaved in pots, too."

I am much looking forward to seeing the color change from white to pink.