If your soil is well drained clay/loam always on the acid side as mine is, and you are thinking of a foundation planting with some overhang of your roof, the east is better, and in the ground. The north side planting will cause your plants to lean out for the sun, and grow a straggly looking plant. Al

I have my hydrangeas on the east side of my house and they do very well. Agree with Al, unless you're in a really hot area of California. If you can include your Sunset zone as well as your USDA zone, that helps us a lot more on this list than the USDA zone, which is sort of useless for us here in California.

Patty S.

I have one on the north east point of a gazebo here in costal region of san diego and and grows great. It gets full sun from morning till ~12 and then partial sun for the remainder of the day. Its planted in the ground and gets watered between once a week and once every 2 weeks depending on when I remember to water it.
Garrett

We have one on the north side of our house, which actually faces northeast. It gets morning sun until about noon in summer, then bright shade for the remainder of the day. In winter, it gets a bit of morning sun.

It was a gift sent to me after my father passed, so it is very precious to me and I took my time searching for the perfect spot -- it seems very happy.

Our summers are hot and dry, typically mid- to upper-90s. Our soil is clay.

I agree with Al and Garrett about east side and in the ground garden is better. What title of acidic soil/clay loam? I'm planning to buy soil bag at Lowes or Home Depot store. I'm interested in 'Nikko Blue' hydrangea plant I believe that bloom color could be bright purple? -Frank.

Frank I would not waste money buying bagged soil to add to your garden soil. Hydrangea are not really fussy about your garden soil and your soil can easily be improved with the addition of compost if your soil is compacted and heavy. People buying Nikko Blue usually do so for the blue flower color. In my acid soil my regular macrophylla Hydrangeas are always blue anyway. Al

I think you are supposed to use aluminum sulfate when you fertilize, because the aluminum makes them blue. The problem is that they have trouble getting the aluminum out of the soil if it is too alkaline, and most of our water and soil is alkaline in CA. Someone else may chime in with a good explanation. You can always ask on the Hydrangea Forum as well.

Frank, Nikko Blue will be purple/pink if your soil is more on the alkaline side. As Renee mentioned, if you apply Aluminum sulfate (be sure to do this AFTER you do a nice deep watering to prevent burning), you can "blue them up". Usually the recommendations are to create a solution of 1/2 oz (1 Tbsp) aluminum sulfate per gallon of water and then apply that to your hydrangeas at the roots. Your hydrangea should be well-established, so you reduce the risk of burning the roots. Apply this solution during the growing season. And, you may need to acidify your water, to make the aluminum available to be absorbed by the roots, so you can try watering with acidified water first (acidify with vinegar to bring the pH of the water down to 5 to 5.5), then apply the aluminum sulfate solution. Some varieties are more amenable to bluing, I think Nikko Blue is one of them, but the Hydrangea Forum should be able to tell you for sure. Plus, I think that hydrangeas planted near buildings or sidewalks tend to be harder to blue up due to the lime that leaches out of the concrete into the soil, and raising the soil pH. But I like that purply color they turn for me, and frankly, I'm too lazy to apply the Aluminum sulfate. But, I think it's kind of cool that they're the litmus paper of plants!

Patty S.

Not an expert but I would think that using a soil with a very high percentage of peat would help a lot. As i remember hydrangea flowers are similar to litmus paper except reversed in coloration. In acidic soil, with the presence of aluminum they go blue, and in basic or alkaline soil they go red. The thing to remember is for the plant to be able to uptake the aluminum the soil has to be acidic with a pH around 5.2 to 5.6. Any higher than this and the Aluminum is not "available" to the plant.
Garrett

My soil was forest until 50 years ago, enough of the forest was cleared to build a house and garden. The trees were milled to lumber to build the house. Soil consistently tests between 6 and 6 1/2. The well water tests the same. This year I have planted new Hydrangea,'Oregon Pride' advertised as red flowered. To be able to enjoy the red bloom I have planted them in containers of 'gritty mix' which allows easy PH control. My garden soil has never been treated with Aluminum sulphate or anything else except homemade compost. Al

There are newer hydrangeas that bloom on new wood and provide a much longer flowering season.

Either aluminium sulphate or soil sulpher for lowering the pH and gettting blue flowers. Neither is an instant fix. Aluminium sulphate is faster, but soil sulpher works too.

Wooded Northern California is more likely to have lower pH soil than scrub sage coastal southern California or inland arid California. California is a big place! There is a lot of variety in climate and soil.

hoovb, I think you actually need to use both the soil sulfur to lower the pH, and then apply Aluminum sulfate to get the blueing affect. There's been some interesting research as to what, exactly, causes the blue coloring for hydrangeas, and I think I remember reading that it really is the amount of available aluminum in the soil. And it isn't available to the plant unless the pH is low enough. So, if you've got plenty of natural aluminum in the soil, and your soil is acidic enough (as in Al's case, apparently, he must have enough aluminum in his soil, and it's just low enough on the pH scale to be made available by his hydrangeas), you'll get blue hydrangeas for those varieties that will blue up. Not all will, either. Pretty sure Nikko Blue is one of the varieties you can get to turn blue or pink, depending upon your soil. Fascinating plant biochemistry to be sure, since my soil pH tends to be around 6.2 to 6.7, same with my water. And I'm S. Calif. coastal scrub with lots of DG. Not exactly wooded forest materials like Al has.

Patty S.