I like Dirr's Manual of Woody Landscape Plants better than Hardy Trees and Shrubs. It doesn't have photos (that's what Google images is for) but it has much more info. And I love his writing style - often opinionated (and I regularly disagree with his opinions because my growing area is so different from his) but well written and with a sense of humor. I use this lots more than any other garden-related book on my shelf and really appreciate the depth of information included. (I also own and use as reference his book on Viburnums, though that is too specific for your purposes.) For well written garden essays, I really like anything by Joe Eck and Wayne Winterrowd. Well-written, excellent plant knowledge (especially for my northern area,) and great design sense, often along with gentle humor. What more could I ask of garden essays? They have a nice one on annuals if you're looking for one that fits a particular category. Most other garden books I own I've read once and may refer to periodically, but in reality I rely more on web searches since I can usually find detailed information on whatever I'm looking for. For design I read blogs written by several professional designers that are well-illustrated with photos. (Disclaimer - I read a lot of books, just don't find they fit most of my needs as an experienced gardener - because of the economics of publishing, most garden books are written to appeal to a broad spectrum and so may not have the level of specificity I'm looking for and they are hard to keep up-to-date with new plant offerings.) However, I am looking to get a good pruning book, so I'm hoping that I can get some ideas here. Thanks for the topic.

'Hamburg' has very deep blue to purple flowers. I also like 'Enziandom' (aka 'Gentian Dome'), both for the deep color and size of the flowerheads. These will need acidic soil to develop that coloring. There are other cultivars that provide very deep, intense color as well, but these two are popular and tend to be more widely available. With the exception of some of the newer varieties that bloom on both old and new wood (and none of these produce very intense color, IMO), macrophyllas in zone 6 should receive winter protection to ensure the flower buds are not damaged. They will be root hardy but the buds - formed during the previous summer and fall - are more susceptible to winter (and spring) cold damage.

My first Hydrangea is now in the ground for more than 25 years. At this point, I keep it for sentimental reasons only. It's gotten so THICK with canes that if I wrap it in my usual cage, I have to get everything so tight in there that I think I may actually be suffocating the plant. I've not had good luck overwintering it in recent years. This past winter I didn't even bother with it. If I were you, I'd consider taking a cutting or digging out a portion of your sentimental one and essentially start over. It would indeed be the same plant, so you could keep your sentiment. But I can understand sentiment. I should get rid of my first Hydrangea, but I'm not. For a long time I would cut back the old canes completely to the ground in the Fall. I'd only leave canes that had shot up from low points on the canes or from the crown. They would have grown all summer and would end up giving me great flowering the next year. I'd have very long stemmed flowers, too, that I had cut. The big problem with this technique is that you end up with weaker stems than you would otherwise and next summer they'd be weighted down to the ground with their flowers. I've found that, for my zone, I can usually prune as hard as I want up until about Fourth of July, just to be easy to remember, and not hurt the flowering potential for next year. After that, the buds start setting for next year and you start running into that problem. (But then I've cut some "nikkos" back to the crown in the Fall and on some I'd get great flowering and on some I'd get none. Do I really understand this? NO.) So, here is another method for you to consider to keep it smaller, at least in height. Another thing I've experimented with is to prune all the wimpy growth completely out and just end up with a few stout canes over time. This was interesting, but you end up with an artifical looking Hydrangea and the few stout canes start looking rather strange. But with this technique, more or less, you could develop a plant that wasn't so crowded. I don't know though. I wish I could help you more. I'd like an answer to the question you have, too! Hay

Amending the soil in pots in easier but watering is more of a problem as you have to water more frequently than in the ground and the sides of the pots can heat up enough to dry soil and roots near the walls. Some people put potted hydrangeas in hot location inside wooden square containers so the outside wooden shell will absorb the direct sunlight and the inner pot will not heat up as much. Of course, you ncan also take care of sunlight issues by moving the pot around anytime you see it getting being hit by sunlight after 11am (ie, I mean the 11am in the hot summer months, not the weak 11am sunlight we have now). Water absorbing small roots are in the top 4" so keep these as evenly moist as possible. Potting mix without aluminum or without aluminum & acidic conditions will produce pink blooms. That is all I get over here too but I am playing around with the amendments. After adding some in Spring, I have to add more again in the early Fall. I let the plant tell me (ie, if it gets iron chlorosis and the leaves go from dark to light green or if the leaves turn light yellow except for the leaf veins that remain dark green). But one Nikko Blue that turned out to be some lacecap get a little more and its bloomage has been purple the last two years. I added still more amendments this year and should notice the results soon as that lacecap is in the broccoli stage and should have open blooms soon.