Posted by Mike G on November 05, 2002 at 22:34:54:
In Reply to: walnut tree toxicity posted by Sylvia S. on October 31, 2002 at 08:01:50:
The suspicions regarding the failure of hydrangeas to bloom due to the walnut trees sounds valid but isn't toxicity. Toxicity would damage the plant where it would die and not grow at all. And since you did not prune, if you're referring to the fall or winter, the plant should have produced flowers. Hydrangeas that grow in DEEP shade, may fail to form flower buds.
Get the plants in a little bit more light by pruning back the walnut trees to allow more sunlight to reach the plants or transplant the hydrangeas to a place that gets at least filtered sun for a half a day.
Otherwise, your soil may have a high alkaline pH that hydrangeas do not grow well in, check the soil pH. 7 is good, x7 is alkaline, anywhere between 6.0 and 7.0 is great. I doubt this is the problem because your plants have bloomed before, but it's good to check anyway.