Nuther question

[James]

I'm wanting to start some Royal Empress trees from seed and plant a row of them along my long driveway. ( PAULOWNIA tomentosa) Anyone had these trees and am wondering about any drawbacks to the idea?

[paghat]

Nature Conservancy's Invasive Species Initiative requests that people voluntarily stop planting these trees even in places where they are not yet illegal. They sometimes sucker & invariably self-seed like weeds, to the point of being invasive. They are illegal in about a dozen states, & are on lists recommended for banning in several more regions. In Connecticut for example (as of this past October) you can be fined a hundred dollars for planting, transplanting, or selling paulownia. The species has already proven itself a danger to native species in several areas around the United States, being worst in the east, south & southwest, but not yet too late to keep it from spreading throughout the west.

They grow rapidly but have weak wood that easily rots from the inside which is naturally hollow. They can snap at any point along the trunk in storms, threatening nearby structures. They are not especially longlived trees. It is recommended at the very least that they be planted only with caution, & their use is strongly discouraged even where still legal. There are so many finer safer choices that can be made.

-paghat the ratgirl

[Cereus-validus...]

Don't do it, Jim Bob.

Its one of the worst weed trees.

[James]

Know of a good substitute for this fast growing tree?

[madgardener]

I can attest to the fact that they are prolific throughout the southeast. They're a common tree here in Eastern Tennessee. And yes, they do sucker. I have a daughter that has risen up on the roots of her mama a few feet down my side slope.

I don't know about the wood being weak though. I have a Pawlonia tree, and yes, she is hollow in the middle. But she only drops the ends of her twigs where the pods are all at. The pods are a pain in the butt, but the flowers (this tree is also called the Foxglove tree) are georgous and smell like grape Nehi. The leaves are fuzzy and if you cut the young trees to the ground each fall, they send up spring shoots and the leaves are as big as three foot across sometimes.

The Chinese people use the wood as dowery boxes for their daughters because it resists rotting and burning. I've only been able to burn the wood when the wood pile is glowing hot and would probably fire clay. It just doesn't start like most woods do. As for rotting.......I have the branches of this tree that were cut for me when they grew over the electrical wires in the side yard by the electric company laid out around the edges of a garden bed and except for the bark that finally came loose, the wood isn't rotten yet and that was three years ago.

They can snap at any point along the trunk in

I've NEVER had any limbs snap off along the trunk on my Pawlonia (I have pictures of her to prove it) and this tree apparently has been here now for over 90 years. Which approaches that remark made below. So 90 years isn't very long, not compared to an oak tree that has to be 50 to produce acorns, but I will say they are messy with their pods and large leaves in the fall.

They are not especially long lived trees.

It is recommended at the very least that they be planted only with

And I AGREE there are other alternatives. But I have three Pawlonia's and until the old mother tree shows me signs that she is about done, I think they last at least several decades. Which is more than I can say for those horrible Bradford pear trees. And I just checked the wood around the beds yesterday for rot is why I wonder how long the wood takes to decompose. I only had to pick up a few end branches with the brown pods as they bloom on new growth, but no limbs or large branches or even smaller branches. Only the end pieces.

Try other trees, and check with your local Agricultural extension agent for good trees to line your driveway with for your location.

madgardener

[madgardener]

[Cereus-validus...]

If you want to grow a similar looking tree that is better behaved, try Catalpa instead.

[Rob Davison]

Bit sweeping. We've had one for 30 odd years. Never seen a seedpod or (unsurprisingly) a seedling in all of that time. It'll be better than 30 feet high.

It will sucker if you cut the root, but IME nowhere near as badly as (say) Populus tremuloides. Gonna ban that one too? :-)

Ten minutes with a spade once a year keeps our Palownia in check. The first year growths are very soft and easy to knock off in winter.

Climate makes a very big difference to how a species behaves. The suits flying desks that ban these things rarely take that into account.

In that case I'm glad I don't live in Conneticut.

Its a good tree.

Rob.

[paghat]

The tree is the kudzu of Tennessee. Since it's far too late for it to ever be gotten rid of -- it's there to stay! -- the University of Tennessee has been doing studies on how it can be used for regional forestry products, & Tennessee is becoming something of the Paulownia capital of North America looking for further economic gains from the tree rather than fighting it off. It's not the ecologically soundest choice, but it's too late to ban it so the state's attitude seems to be "let's see what we can gain from it."

Our native Pacific red elderberry is also extremely HARD wood that can be used to make extremely hard objects, but a big Pacific elder can be knocked right over even by a bear or a moderate wind. They can grow ten feet in a single year so are very weak, despite the surprising hardness of the brittle wood.

Poulownia wood is rot resistant once it is turned into wood products, & the outer part of the trunk can be used to build something that sits on damp soil for decades & barely rot. But a living paulownia tree is susceptible to a whole host of diseases, & most especially root, ring, & basal rot caused by fungus, which soon extends through the interior of the tree. The outside of the trunk might never show advance signs of a problem. Rot can also enter a tree through broken limbs, or reach the pith through the circlular tissue plates that appear at intervals along the trunk, especially when limbs break off or are pruned from these tissue plates which are quite thin. Emilycompost.com notes that "Canker, die back, powdery mildew, wood rot and mushroom rot are the most common" problems, of many, experienced by pawlonias.

Adult trees that drop the ends of their limbs with great ease are showing signs of systemic pith rot; new tissue for young limbs is being infected through the rings, so the trees become weak-stemmed. These trees may seem strong at the outer wood, but can snap in two high winds, at any tissue-ring along the trunk. Anything else that grows as fast as pooulownia will also be susceptible to blow-down, so if blow-down would mean crushing anything someone didn't want crushed, like house or garage, then trees that grow swifter than a foot a year are not sensible choices. Trees that put on ten to twelve inches a year are fast enough, without loss of structural strength. If it doesn't matter that it'll be at risk for blow-down, then a large species of willow or a poplar will be better choices among speed-growers because not invasive.

Young poulownias prepared for market are slathered in fungicides because of their notorious rot problem. Often rot is already present long before the young trees reach retail vendors; & fungicides are soaked into the rootball as it is packed in sphagnum to ship from grower to nurseries. Some people have the impression that young poulownias are particularly susceptible to rot & need babying their first few years, but this impression is due to the poor production methods that merely use fungicides to keep the fungus from progressing much until the product can be sold.

I suspect even if never touched by the fungus the wood would still be brittle & susceptible to breakage in storms.

Some of the problems are no worse than for old willows or giant old maples, so needn't be cause for complete paranoia, but rot does often develop sooner in the heart of poulownia than for a maple because the poulownia matures (then declines) so much more rapidly. The bigger reason not to plant them is probably still going to be their problem as major invasives.

Horse chestnuts, especially a cultivar like the pink-flowering hybrids, can be a good substitute for poulownia. Walnut can be a good substitute but walnut will not permit much to grow inside its drip-line. Locally native species of maples & willows could also be assessed for their possibilities, since many salix or acer natives grow very fast & would be low-maintenance for the regions they evolved in.

-paggers

[James]

I did some reading and I believe Catalpa may be a better choice for waht I had in mind.

[Ann]

Rob Davison expounded:

Same thing here, there's one the next town over, only one I've ever seen around here. They're not hardy enough around here to get very invasive (which doesn't take away from the fact they are a horrid weed tree in warmer areas of the country).

[Ann]

Rob Davison expounded:

A horrid weed tree invades and drives out native species. Around here the horrid weed tree is the Norway Maple, it's invading forests, deeply shading the ground below (kills ephemerals) and shades the native tree seedlings, understory shrubs, etc. Not a nice plant. Of course it isn't the weed tree's 'fault', it's not a sentient being. But allowing the spread of non-native species is not a good thing to do, if you can avoid planting the invader, then you should do so. Growing the plant where it belongs is one thing, growing an invasive species where there are no natural controls is another. I wouldn't wipe the last of anything out, but there comes a limit.

I'm a member of the New England Wildflower Society, the subject of invasives is near and dear to many of our hearts. I don't want purple loosestrife killing off our beautiful native cardinal flower (lobelia cardinalis), no matter how pretty the purple marshes look.

[Iris Cohen]

Rob Davison expounded:

[Rob Davison]

Hi Iris. For your information until quite recently NZ had no 'pest plant' control laws at all.

On the one hand our geographical isolation has helped to limit the arrival of exotic plants and animals - but on the other that same isolation has produced specialised plants and birds which do not tolerate a change in the ecological balance at all well.

I believe that change is a part of nature however (and a part of gardening!) and feel that those who seek to control and prevent all change, who seek to 'preserve' nature without accepting the fact that it is by its very nature(ha!) a dynamic, evolving, system are working on something far more artificial and ultimately more damaging to the environment than the introduction of new species - which happens without human intervention anyway.

In the long run they're also on a hiding to nothing as we're all on the same ball of rock. Keeping an eye on that fact is far more important than trying to wall off your particular bit of it from the rest.

I do not advocate open slather. I do advocate commonsense, education and personal experience of how the natural world really works.

How about hours crawling around under old Rhododendrons looking for the roots of Elderberry, Blackberry and mulenbeckia vine (two out of the three are exotic here. The native is the biggest weed. Go figure...) ?

Or hours tracing chickweed plants through wet Astilbes to find their hairlike root (how such a fine root supports so much lush top is truly amazing)?

Hours spent picking creeping epilobium, clover and native orchid out of the heather garden? same area is also infested with two garden plants that 'do too well' here. Viola biflora and Scilla campanulata. We work at keeping them away from that part of the garden as they don't fit with the neat shapes of the ericas, callunas and dwarf conifers.

Time spent ripping lotus out of clumps of sibirian and higo iris perhaps?

Spraying tall willow weed (another epilobium) and californian thistle around newer plantings of rhododendrons, shrubs, dormant daffodil and colchicum borders?

swamp grass in patches of Ishriach hybrid primulas and P. japonica? grandiflora that (left unmolested) will climb on top of a healthy clump of Hosta and smother it?

Purple creeping oxalis crawling around the rock garden?

All of the above, plus a few more making merry in the perennial borders?

Would my lifetime (34 years and counting) involved in such activities do me in lieu of your experience with Acer platanoides do you think?

Does it add weight to my opinion, or at least grant me the right to hold and express one that I'm well aware is (at least in part) contrary to the prevailing eco-friendly, 'green' point of view espoused by so many city dwellers?

My elderly parents and I have a garden of about 20 acres in size called Maple Glen. We design, create and keep it by ourselves, for ourselves and we're still extending it.

me Iris, I know my weeds.

I also know which garden plants have the potential to become weeds in our location and what to do about it. I do not appreciate being told that I can no longer grow something on my own land that has lived here (without causing much trouble) for 40 odd years by somebody with soft hands and no honest dirt under their fingernails who has read a study that finds the plant in question causes serious trouble in southern Louisiana and then decides on that basis to ban it here - where the only thing between us and the earths south pole are a couple of penguins.

There is also (I believe) a political agenda at work and that riles me too. If people want to grow only natives then that is fine by me. I defend their right to grow whatever they want on their bit of dirt.

Provided they grant me the same.

Now, how much of the above do you have trouble with and if you disagree with me (as I assume you will) can we at least see each others point of view and agree to disagree? :-)

Rob.

[Rob Davison]

But then you have a native maple that creates very similar conditions. Acer macrophylla. It self seeds like crazy too. :-)

One of my aims is to have a dark grove of these with fantastic moss and litchen covered trunks - as photographed by Thomas Packenham for his book 'Remarkable Trees of the World'.

When I'm 90 and in a wheelchair I might just have it - provided the powers that be don't try and kill off all exotics before then...

And yet people emotionalise the issue - calling these plants 'horrid', 'evil' and such.

This I fundamentally disagree with. Apply your point of view to the variations of our own species and where does it lead?

We happily grow both. Some here would deny me the right to grow these plants purely because they didn't evolve on these islands.

You'd agree with them?

Rob.

[Cereus-validus...]

New Zealand has one of the most wonderful endemic floras on the planet. I would suggest you learn more about it and appreciate rather than try to screw it up because of your naiveté.

[Rob Davison]

Dull as hell, most of it. We grow the exceptions - Chatham Island Forget-me-not (nice, but tricky to do well unless you have ready access to piles of rotten seaweed), Mount Cook Daisy (Celmisia), Kakas beak, Kowhai (though 90% of those died in the winter of 1996), a Kauri that has managed to evade the frost, Cabbage trees, Tree ferns, Astelia and a bit of tussock (carex testacia) and flax around some of the ponds.

That's about it.

I would suggest you mind your own bloody business.

If you want to be racist and choose plants on their country of origin then go right ahead, but leave me out of it.

Rob.

[paghat]

Over two-thirds of New Zealand native plants are endemic to your country, hundreds of them gardenable, many suitable for the nursery trade including many not yet developed by growers, so new stuff can be expected in years to come. Some of the coolest shrubs in my Pacific Northwest garden, especially the flowering hebes, are native to New Zealand, & even for just this one genus the variety is extensive. One of my favorite ferns is the diminuative fully evergreen Blechnum penna marina from New Zealand. Rengarenga (rock-lily) with its sprays of white bloom is very showy for under trees, good for dryish shade where it fills a niche similar to English bluebells. There's a variegated New Zealand myrtle; pepper-tree shrubs; golden sophora; red-flowering clianthus; tufted astelia; the "Libertia" iris; native clematis; crimson-flowered climbing carminia & other Metrosideros varieties; aster-like rock daisies (Pachystegia insignis)... I'm not personally fond of ornamental grasses, but New Zealand native caryxes & flaxes are in general very popular in Northwest gardens.

For temperate gardens it may be that New Zealand isn't as flowerful as our own Northwest native flora, nor comparable to what has come out of the Himalayas or Hunan Province, but it's far from unimpressive. If the increasing varieties of hebes were the only things New Zealand had given to temperate gardeners round the world, that'd be quite something to boast about.

-paghat the ratgirl

[Cereus-validus...]

Thanks paghat. Rob is just showing how botanically retarded he really is about the riches growing in his own back yard.

From the various books of New Zealand flora I have read over the years, I have been very impressed by the large number of garden worthy species endemic to the islands and found nowhere else on the planet. Only a very small number of species from the islands, mostly Phormium and Cordyline, have already become garden staples and that is only the very tip of the iceberg of the garden worthy plants. Many of the New Zealand alpines equal or surpass their European equivalents but remain virtually unknown by most gardeners around the world.

Rob should try to make an effort to make seeds of these plants available instead of dismissing them.

[Ann]

Rob Davison expounded:

Not at all, we're all gardeners, we all grow exotics. I guess you just don't mind natives being driven out by some exotics, I do. I won't purchase invasive plants, nor will I encourage their spread in the wild.

Let's apply the same logic to this: someone imported lily bulbs with red lily beetles (Wellesley, 1994) and now our lily collections have all been decimated by the spreading beetle plague. Same principle. Introduce an exotic species with no natural controls and the introduced species spreads out of control. Plant or animal, it's not a good thing to encourage.