Micro-Climates

We garden in 6a according to tables. We live on a high knoll, about 3 acres of totally scraped ex-cow fields. Although we plant small trees continuously, the winds and temps here create a definate 5b.

Any ideas on how to create some mini micro-climates where we could enjoy growing some other perennials? Would a pond surrounded by rocks/boulders help any? We could do that ourselves if it would. Thanks!

Water would help, but it would have to be a fairly large size to help much. I am not sure what surface area would be required for a degree of improvement, but I vaguely recall at least 1,000 sq ft. of surface area.

Anything that can be done to create a wind barrier would help. Evergreen or deciduous trees, shrubs, fencing, buildings. Most people scream at the thought of fast-growing trees, but in some circumstances they can be your best friend. They provide good nursery conditions while other plants become established, and are usually easy to remove, as long as they don't leave lots of suckers or seedlings around. Poplars, Blue Atlas Cedar, maple (I am shuddering at suggesting maple!) Hemlock would also work well. Even privet! It doesn't have to be kept clipped; if there is room, naturally-shaped privet can be a lovely billowy hedge at least 30' high.

For a tiny microclimate site, a south-facing white wall, with another white wall facing it will give the ultimate help, as long as there is not a tunnel to make the wind go through even stronger. Again, windbreaks are essential. Think "walled garden" for a good example.

If you have any valleys, put boulders or other cold-barriers in a winding pathway to prevent the cold air from streaming down, much like water streams downhill.

DH and I are sitting here 'chewing' on all your advice - you got a talent and I appreciate the advice.

What about a stone or brick wall behind one of your flowerbeds? We have stuff that would not normally survive our zone 5 winters doing well against the back of our house, next to the red brick. It collects heat from the sun and keeps the ground and air warmer around the foundation. The downside of a solid wall is heat also builds up in the summer and there is no air circulation.

Also consider the circumstance of drainage. Some plants will survive a winter but drown in the thaw. We can grow many plants outside our zone if we do as has previously been suggested, but also use raised bed to keep the soil warmer and drainage at its best.

True! And you also have to be sure the wall does not create a frost pocket at the bottom of any incline. There's a lot of factors to consider.

Sometimes you just have to try creating your own micro-climate, hoping the plants make it. It's a learning experience, and sometimes the weather cooperates and sometimes it doesn't. Once you accept that, it becomes more fun than disappointing.

Sometimes they're complete surprises, like the back of our house. I had elephant ears come back after a winter that went down below zero several times -- woohoo!

Temp is only part of the equation. Often too much standing water crown rots our plants. They don't mind the cold temps, but excess standing water and the change from freeze to thaw all winter can really play havoc.

Dea, you might check out a couple of good books on passive solar design from the library. Most of the ones I have are quite well illustrated in designing a proper windbreak for the site. Most wind patterns during the winter are constant, so it's fairly straight-forward.

Ba erms seem like good idea but you have to be careful not to create a low spot where cold air can settle. I'm less sure about a pond since I have no experience...

I like the idea of opposing walls LupineLover mentioned above.

This is probably the most interesting discussion I've seen in quite some time. All of you have given us things to think about and research - drainage, wind tunnel effects and low areas. I can already see some mistakes that we have made. This is just great - thanks all!

One more thing, Dea:

Never abandon the attempt to grow something out of your zone until you have killed it at least 3 times!!!!!

Another point to consider is that many times, the zone hardiness listed is referring to a mature, established plant. That is most true with woody plants, but also with iffy herbaceous or evergreen perennials. If you can nursemaid them through the first winter or two using extra protection, more likely than not, they will become at least root-hardy. Young transplants are the most vulnerable.