Posted: 05/10/2014 at 17:58
Hi Ellen - yes the east coast is generally colder but drier, whereas we get long cold wet winters, although we do get frost and snow as well. I can see how it might be tricky to keep enough moisture for plants with your soil conditions! The more planting you have, the greater the competition for moisture too. You're doing the right thing by mulching anyway, and that will help prevent freezing as well as retaining moisture in dry weather.
Can you get farmyard manure there? It helps enormously with moisture retention, and conversely helps with breaking up and improving heavy clay. If you have a riding school or stables nearby they're usually happy to give some away, but it's also available in a bagged,ready to use form here in GCs and DIY stores. Some of that dug into borders should help with water retention and boosts the nutrient levels. Interesting that you're also seeing a definite change in your weather there.
Hope the Viburnum is doing fine