Warning -- you're gonna get harassed for even mentioning Paulownia. That said, they transplant rather reliably, and if it has grown since transplanted, should be OK. You really can't overwater it, but just a good watering once a week should be OK, unless you're already getting good rains. After this season, it should be alright, unless you're in a particularly dry climate.

@bengz6westmd Bart is in Italy, and she endures a VERY dry Mediterranean climate. That's why she mentioned the June rain, as it's unusual to get ANY rain other than Winter/early Spring. Summers are extremely hot and dry (especially lately). Plus, in Italy, pawlownias aren't known to be invasive, probably because of that summer dryness. They are beautiful trees where they can be contained.

Here, one paulownia rapidly becomes many. My neighbor has one (a gift from Mother nature, not purposely planted), and I have to be on the lookout for seedlings on my side of the fence. I had one come up in the edge of my vegetable garden, which is nearly a quarter mile from his tree.

Thank you both. Not to quibble, but traditionally at least we should get rain in autumn and winter, tapering off in spring. Once upon a time, it used to sometimes rain even in summer, but alas, no more.

I wish there was an easy answer to this!

Just a minor observation that people shouldn't think of the climate of all of Italy in a monolithic sense.

Although most of the country does have a Mediterranean climate, the western parts of the Italian Lakes paradoxically have the opposite climate, with a summer peak of rainfall, and likely the highest early summer rainfall figures you will find anywhere in Europe!

https://en.wikipedia.org/wiki/Lugano#Climate

(station technically in Switzerland, but very close to Italian territory)

Even Milan has more of a summer peak of rainfall.

https://en.wikipedia.org/wiki/Milan

But just a quick hop down to the Med. coast, and you're back to a "Mediterranean" climate!

https://en.wikipedia.org/wiki/Sanremo

This is surely the place in the world where these climate types come the closest to overlapping. The transition from Adelaide to Sydney is over a vastly greater distance. Melburnians can safely consider their climate Mediterranean, but really it's a weird Aussie one-off with more of a spring/fall peak than a winter one.

Some would argue you get this in the American southwest; but the 'summer monsoon' is SO unreliable the closer to California that you get, it's hardly the same as what's going on in Italy. Nevertheless, it surprised me that this town had as much summer rainfall as it supposedly does:

https://en.wikipedia.org/wiki/Bisbee,_Arizona

And btw, I would have EVERY reason to believe Paulownia is invasive in those summer rainfall parts of Italy! I'm pretty sure I saw weedy ones growing by the railroad tracks on the outskirts of Milan. The seedlings of "Chinese Windmill Palm" - Trachycarpus - grew so thickly in roadway medians in Stresa, Italy, that it appeared they were being trimmed to make a very bristly lawn!

David, it is indeed true that Italy is full of microclimates! Sad to say, however, our area has become terribly dry and hot during the summer.

I don't know paulownia, so I don't know how well this translates. Until recenly I lived in the Mediterranean cimate of the San Francisco Bay area, Cupertino to be exact. I had three native oaks planted after losing a large Italian stone pine to age and gravity. They were around 10 feet tall. I was advised to water them regularly for two years to get them established.

When establishing trees, you not only have to consider what type of tree, but what kind of soil and subsoil you have. And if you have had soaking rains during your last, recent rainy seasons.

Here we have a nice topsoil that grows plants about as good as anywhere, but the subsoil is coarse sand for at least 10-15 ft down.

During our droughts, the last few years, mature existing trees and shrubs depleted the subsoil of moisture and you had to water new shrubs and trees frequently to keep up. The heat, wind and sun would dry the surface so fast, and with no moisture present in the subsoil, it wasn't long before things were drooping and withering.

Once soaking rains came this spring and summer, it's been so much easier to maintain things because even though the topsoil dries, it wasn't completely dry deeper down.

Now OTOH, parts of my area have the same topsoil, but the subsoil is rocky, gravely clay mix that holds moisture very well and hardly ever dries out unless full scale drought continues for some time.

An established tree has no problem surviving long periods without rain in this type of soil conditions once its roots are down deep.

Lastly, I know nothing about Paulownia tomentosa. All of our woody plants/trees here have a winter dormant period and will grow their existing roots on into the late summer and fall, then produce new roots in the spring when they exit dormancy and begin growing again.

Therefore, it can take at least two seasons for a transplanted tree, with roots having been chopped from the ground, to produce enough new roots for it to be considered 'Established' again.

With a tree like Paulownia tomentosa which has aspirations of taking over the world, it might not take as long to make new roots as it does in my part of the world and may have better resistance to dry conditions, but I imagine it will take some time before it's ready to stand on its own without supplemental irrigation. hth: :-)

@UpperBayGardener (zone 7) No one suggested that Italy is a mono-climate situation. I was speaking from knowledge of Bart's personal situation, in her particular location, and from a statement Bart had made in the original thread about moving her paulownia, where she stated that *in her area* they were not considered invasive. Fifty miles away, in another climate, they may well be.

We did have really good, soaking rain for months after I moved the Paulownia.The soil is definitely rocky clay,not sandy, but at least in some areas of my land it is not very "deep"; that is,this land is on a high hill,and the bedrock is not far from the surface (though the spot where I put the Paulownia didn't strike me as particularly shallow). I also must mention that I cut off very little of the roots-I more or less bare-rooted it when I moved it,so it doesn't have to start completely from scratch.

Bill, I don't know what your fall and winter are like, but here they are very mild. Roses,in fact don't ever really go dormant; lack of light stops the top growth, but I think that the fall and winter is the time for roots to grow ,at least for roses. I don't know how trees behave in this sense.

@Rosefolly z5-I've heard the "two year watering rule", too. But , again, relying on my experience with roses,I've found that an established rose with a good root system that has been moved can deal with being watered only in the first year after the move, after which it can usually get by on rainfall. I'm speaking of climbers and Old Roses,not of floribundas or such; again, not sure about trees. However, a potted rose-even a climber orOGR-needs watering and coddling for several years afterward, because it has to develop those big, fibrous, woody roots that can access water from deep within the soil. I'm assuming that your new trees were "balled and burlapped" (is that the right phrase?) or potted? Wondering again -since my Paulownia was moved with a lot of it's original root-system intact, might it establish faster than a potted one might? Thoughts?

Our trees were potted, and I thought (assumed) that they had been grown potted, and therefore had their roots intact. Of course the protential problem with a tree grown potted is circling roots which can kill a tree some years down the line. We had an earlier tree that turned out to be in just that situation, and one of these two trees was a replacement for it. We went to a different vendor this time, and inspected the root balls of our trees very carefully.

I will never know how these trees turn out because we have moved 1000 miles away, but I believe they have every chance of doing well. I hope so. They were beautiful trees.

Sounds like a great spot Bart.

As usual keep an eye on it.

;-)