You may have had a 'warm' winter... how cold did it get there this year? (zone 6 can get down to -10º)...

It does seem a little strange to me that Kentucky would be in a zone that gets down to -10.

I lived in Louisville for a couple years as a child and I remember one winter there was an ice storm that shut down the schools for a month. This would have been around 1977. I remember my mom (who is from Minnesota) saying Kentucky just wasn't prepared for this type of weather.

If you look carefully at the zone map you will see many weird things. The zone starts on the east coast then drops down to the mid west, all the way down to northern TX(!)

redsox, Boston is on the ocean, which keeps the temps milder.I bet further inland up in New England it's zone 5 and then 4. My friends live in Nashua in zone 5 and just moved further in to zone 4. They are not going to grow roses there.

I have the same thoughts coming from Long Island (New York) which was zone 7 and now I'm in Georgia, which is zone 7. At first I said WTF? but it's just the absolute lowest temp you can get down to which will kill a plant. It doesn't measure length of time below freezing or anything else. And it sure doesn't account for how hot or how much more sun you get in the summer. So take it for what it's worth, just that absolute lowest temp (cold hardiness).

You know now that you can grow stuff that would never work in Boston and there is some stuff you can't grow now because it gets too hot. I was at my Mom's back on LI last week and I love her yard. So green and lush and MOIST. While I'm stuck here in the desert (or so it seems now) but having spring in late Feb as opposed to April is kind of worth it.

Here are some pics from my Mom's yard. She has Bonica roses that finished blooming. I tried to tell her to take out some of the old wood, but she didn't want me to touch them :(

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Actually on the ocean, as in Cape Cod and the Islands, the zone is even higher. This would make a bit more sense. I have seen it get down to abot -3 here for about a minute, maybe once in the 7 years I have been here but -10 could happen.

Boston has much more prolonged cold and I am not talking about Boston proper which is on the water, inland is also zone 6.

According to the new zone map, I'm now in Zone 6 here in Peoria, IL, but I'm not buying it. I can still remember winters where it got to -20 degrees; even last winter we had days where it was below -7.

Now the revised Zone map says we're both Zone 6 now and I'm just 200 miles south and west of Chicago.
-terry

Zoning is certainly an inexact science. Zone 6 in New England is very different from zone 6 in Kentucky. And then you have micro-climates. Most of my zone 6 garden is really zone 7 because my beds are on the south wall of the house. The house supplies heat and plants are protected from the winter wind.

Boston has a reputation for cold winters because of the way the wind blows across the river. Cold damp air feels more uncomfortable than cold dry air. Chicago has an even more pronounced winter wind/water affected climate.

I agree with those that suggest you confer with those in your area to determine what will survive.

Can you grow St Patrick in Kentucky? It is notorious for not surviving around Boston.

redsox, we feel cold differently than plants experience it. We have internal body temperatures and so humidity plays a huge role in our perception of heat and cold. Plants don't work that way, so cold is cold and hot is hot, whether humid or no.

Having said that, as was mentioned upthread, the hardiness zone is based upon an average maximum cold temp., not the number of days where the temps. are in the 20's vs. the 30's. It is indeed an inexact measurement. It always has been.

Redsox -

Kentucky *used to be* zone 6. Now, most of it is zone 7, according to the new Arbor Day map. Also, aside from variations mentioned by other posters, there is a full zone's difference between the coldest part of 6a and the warmest part of 6b. I'm also in New England, and we've gone in recent years from zone 5 to 6.

QC

Here is a link that might be useful: Climate Zone Change Animation

Zack, I don't personally grow St Patrick, but I know people here do.

I thought the zones were average MINIMUM cold temps. Or actually not average, but the absolute MINIMUM, now that I think of it. It has not been -10 ever in my 7 years here.

QC, I will take a look at that new map. I know Jeri said we may be Zone 7 now...

Actually, based on that map all of Kentucky is still Zone 6.

I'm not impressed by the Arbor Day Map. It is too generalized to be accurate in my area of NorCal, which doesn't mean it isn't more useful elsewhere in the USA.

I've found that the National Gardening Association zip code finder is far more accurate for the actual low temps in my transitional locality. For roses, the difference between Zone 8b and Zone 9a doesn't mean much, but for many marginal perennials, it can make a big difference.

Here is a link that might be useful: Zip Code Hardiness Zone finder

Cass, I totally agree. The new Arbor Day zone says I'm Zone 6, but the Zip Code Zone finder puts me at 5A, which is more accurate. If I planted zone 6 hydrangeas, I guarantee they would not make it through a cold Illinois winter.

For many new gardeners, the Arbor Day zone map can be very misleading.

It also puts Newington CT in 5A. But, I don't seem to have problems growing Hybrid Teas like Dainty Bess, Moon Shadow, Elina, Opening Night, Midas Touch, Leibeszauber, Voluptuous, and Artistry. I have had trouble with Burning Desire, but I don't know anyone who likes that one. It is the only rose that I've torn a Dr. Huey sucker off of.

Redsox -

The link I gave is to the Arbor Day animated map. To see the change from zone 6 to zone 7 in Kentucky, you need to hit "play." There are other maps on the Arbor Day site showing the old and new zones. The need to view animation may have confused others, also. I think the map is very useful to give an overall estimate of the recent warming and a "heads up" to those experiencing zone creep. These things are sort of like 100-year flood maps. If one looks up the all-time record lows for any particular locale, they are typically MUCH lower than the zone parameters would suggest.

Hope this helps,

QC