I suspect that plant zones, microclimates, effective gardening practices and the like are not a matter of "theory".

That does seem strange you cannot grow Agastache in the dry part of Washington state. I understood it has a rather xeric climate but do not know specific areas for this. I got to see these flourishing up the street but cannot seem to grow them in my yard so far. I am trying something new with the soil this year but already expounded on that too.

Anyone who grows clematis has to do some serious deep soil amendments around here. I think they add a lot of peat and other organic matter and its a matter of keeping the roots shaded like you said. Its not one I covet so I have never bothered, some people get real into them though.

I tried twice to grow Prince's Plume (Stanleya pinnata). It always germinated, grew well, bloomed, looked fine and then just up and died in the middle of summer when it was dry. Very odd. I had it in a very well draining spot but I think the humidity is a problem on some plants. In theory, this plant has no business growing here anyway, its too xeric.

No one expects tulips to grow reliably beyond a season in the midwest, each year they just sort of keep getting weaker or not blooming at all or just disappearing. I have always understood they are to be replaced each year for good results. Maybe some other bulbs act the same?

I stick to Native American plants. In theory, they should and do fare better. Actually they are the plants I like better 99% of the time. The harder part is finding a source for the plants or seeds in the marketplace. The popular common natives most people think of when you say "native" are easy to find. Its the obscure interesting ones that are a challenge and I often have to rely on trades from a person who has them growing locally and who is also interested or even aware of them, which is even more rare to find. Such people are few and far between. Anyway, when I finally do locate a given source, nothing is more frustrating to end up with an "In Theory Failure" after going to that much trouble and research.

Digitalis purpurea/foxglove--grew it from seed via winter sowing, had good germination rate & healthy seedlings that didn't like the part sun bed where I planted them so didn't return in Y2. Next door neighbor has it growing in his part sun area and it shows up every year. Harrumph! (Could be a result of my mulching with 3+ inches of bark mulch spread over corrugated cardboard. Hmmn)

Species Clematis that my mom planted umpteen years ago in mostly sun, consistently moist soil thrives since it's been growing in that spot for about 30 years. She was convinced she couldn't grow Clematis so I planted several after I moved here. Newer cultivars planted by me where they should thrive haven't grown particularly robust altho' all are still alive. I hope (perhaps) 30 years from now whoever comes after me will enjoy them since I'm guessing they may take that many years to become "established."

Species Agastache returns reliably year after year, grows nearly as tall as me. The pollinators are all over it from early in the year until fall. I've tried growing A. rupestris, aurantica & hybrida from seed via winter sowing. The seeds germinated well but all varieties failed to return the season after they were planted out. My assumption is that while I enjoy the variety, they aren't hardy cultivars (or else didn't like the soil conditions).

CMK - I think it's likely that excess moisture does Agastache cultivars in since I've read they like it dry.

I gave up on tulips 40+ years ago--they're just varmint food after their first season. I'd rather spend my discretionary income on more hellebores/Lenten roses. In lieu of tulips I grow Siberian iris cultivars via winter sowing from harvested or traded seed and enjoy their (briefly) vivid spring colors. Doesn't hurt that they're varmint/pest/maintenance-free.

Grape hyacinth, Puschkinia (striped squill) and daffodils have naturalized in my lawn & in the garden beds so I've let them do so since moving here. Fritillaria thrived where my mother planted them many years ago but when I moved them they didn't thrive.

I had high hopes for the Chelone/turtlehead I grew from seed a couple of winters ago. The plants thrived when first planted in part sun but have diminished in size over the years following. It's very disappointing since the pollinators really work them while they're in bloom. According to my perennial guide book, they thrive in 'Humus-rich, moist to wet soil.'

These pictures were taken the first year mine bloomed:

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Seems to me that Japanese painted fern + other hybrid ferns aren't particularly robust. I've planted a number of them in full shade beds with healthy soil--while other shade lovers thrive, the ferns diminish in size year after year.

While not an "In Theory" plant, the same cannot be said of variegated Japanese sedge--it's not only prolific, I'm inclined to describe it as aggressive.

-GP1 and gardenweed, now I think of it, a neighbor once had a couple clematis grow well for her in certain locations. It seemed when she planted them in heavily amended soil they did okay but when she planted in a hot/cr*ppy soil location they looked dreadful.

I would be very interested to hear if someone who lives in the same hardiness zone but has superior drainage/less winter wetness has the same issues with the Agastaches being short lived. I often wonder if the dampness is the only factor, or they tend to overestimate hardiness listings, or both. gardenweed, which ones have you found to be perennial? A. foeniculum is the only one for me...

-gardenweed, I've read that too. I wonder if pH has anything to do with their success or not? It's funny though, since we have some chelone in large 5/6gal containers at work that have been planted up since last year (dug up from old flower bed there) and they do phenomenally! The soil isn't great and they don't always get regular water. Go figure! Seems when you want to grow something it won't happen and then when there is no care involved the thing goes nuts!
CMK

My area gets 40-50 inches of precipitation annually, spread out fairly evenly through the year, though snow tends to last all winter creating what is referred to as 'mud season' in the spring when the ground is still partly frozen and doesn't drain well as snow is melting. I have had success with Agastache rupestris in places with unmulched steep slopes. (see the left edge of the photo below to get a feel for the slope. My Agastaches are at the far end of that bed with a similar slope, though they don't actually show in the photo. Where the Hydrangea is there is less slope, so more moisture.) Since all western Agastaches are at best borderline as to hardiness for me, most don't survive, but the A. rupestris will often last 3 or 4 years before cold, too much cool weather damp, or voles do them in.

I have had some success wintering over marginally hardy western Salvias in large pots in the cold attic of the ell (over the kitchen, but unheated), so I may try that with some of the marginal Agastaches since I really love them.

Not really perennials, but I've had several "in theory" small shrubs and subshrubs not do well. Itea 'Little Henry' dwindled over several seasons until I couldn't stand it any longer and shovel pruned it. Most Russian sages/Perovskia and some lavenders don't overwinter for me, even in the steep, well-drained areas where A. rupestris will. A couple of the hydrangeas that are supposed to bloom on new wood haven't for me, and since they die back to the ground most winters, they may be doomed to be shovel-pruned or offered to others in my area who live enough farther south that they might have success.

And just to add my experience with Clematis, it is even moisture (but still well-drained), not shade or cool temperatures that they need. Probably half of my Clematis thrive in all day sun (14 hours in midsummer) and temperatures that can exceed that of New Orleans in July and August with accompanying warm soil temperature. As long as I don't let them dry out, they are fine. Shaded roots and mulch just tend to decrease the chances of the soil drying out. Planting a few inches deeper (except for the Atragene group) encourages extra root growth and discourages drying out as well. My Turtlehead/Chelone grows in a similar circumstance to the clematis - lots of sun and average, but even moisture.

gardenweed, what do you mean by species agastache, the ones that grow as tall as you? Is it an unnamed type from wild seed or something?

My experience is that the agastache looks fine until it rains or I water the area its growing in when its really bone dry and other plants that like conditions a bit on the dry side are starting to look distressed. Its as if they get one single hit of moisture and then the next day, the whole plant crinks up and then turns black. This was the same thing that happened to the person in Dallas who wrote in about it on the Texas Forum. You wouldn't think they'd be that finniky and die with a single drink but that has happened to me more than once. Last year I tried A. rupestris from a seed pack I bought locally and each one did this after a rain. They had been growing fine until one incident of rain happened.

christinmk, High Country Gardens lists most of their agastache as being hardy in zone 5. I suspect moisture issues are the culprit more so than cold hardiness. They also recommend low fertility. How rich is your soil? Are you able to grow western penstemons or Salvia dorrii up there? I am tempted to try one of the California desert Salvia's but "in theory" the odds are against me. I have good luck with the more forgiving types like S. greggi and that big bush type called 'Lips' which gets huge. I do well with many of the western penstemons too, others not so well. They self sow freely so I always have lots of them.

A plant I cannot get to live past a couple of seasons is lavender. I finally decided lavender is an unreliable, short lived plant in Oklahoma, destined to die on you right in the middle of the growing season leaving a big ugly hole in your garden. The plants I have always lost are big full grown plants that look perfectly healthy and then they just start dying bit by bit. Makes me sick because I love the smell and looks of it. Is it too hot? Too humid? What? I do not know. When a mature plant just up and dies for no apparent reason you are just left to guess.

My mom who lived about 90 miles north of me grew many varieties of clematis. I remember she was always very careful and exacting with the soil, location and care but they did do well for her. She finally ran out of types to collect, it was a sort of obsession for a while with them.

-nhbabs, thanks for your comments on agastache and clematis. That's a gorgeous shot of your garden btw! Which type of sumac do you have growing on the end there?

-GP1, the soil tends to be on the leaner side. I've contemplated trying other penstemons, but have never followed thru with that either. My original plan when I took out some of the lawn in the front was to put in a sort of rock/droughty/scree garden to try my hand at those plants that need a lot of drainage. Then naturally my plan morphed into something else, lol.

Have you thought about trying Lavendula dentata & stoechas? Those are said to do okay in humid sites...
CMK

Rhododenrons are one plant I'd love to grow but have given up on trying as all those I've planted have promptly died! The next-door-neighbour grows them easily and there are some beautiful ones in the neighborhood - always out of sight in the backyard for some reason....

This neighbourhood is on old lake-bottom - in pre-historic times this area was on the margin of the lake that existed prior to Lake Ontario. The soil is either fairly dense clay or almost pure sand, depending on where the piece of land is relative to the old lake margin. We are largely heavy clay except for one bit about a yard square near the shed. That spot is almost pure sand that extends very deep. The people who grow rhodos sucessfully tend to be on sand - and water a lot! I think my soil is also fairly alkaline so that, plus heavy soil and dry shade, doom any attempt to grow rhodos here!

Clematises, on the other hand, do well here - except when they are water-stressed as some have been here after the past few very dry winters. I think clematis are more lime-lovers than they are usually said to be. The ones that do best for me are those that are planted near a source of lime (e.g. near a foundation or a concrete footing of a post, etc.)

Lavender also seems to do well here - some of the plants arre more than 10 years old. Tulips also do well here and come back for many years. I tend to plant types that are more inclined to naturalize, so that helps a lot I'm sure. My favorite, Ivory Floradale, have been coming back and increasing for more than 10 years now and are one of the things we particularly enjoy in the garden in spring.

From the sounds of it, agastache would not be something that would be worth trying here :-)
.

gardenweed, what do you mean by species agastache, the ones that grow as tall as you? Is it an unnamed type from wild seed or something?

GP1 - The first year I winter sowed perennial seeds, I got some Agastache foeniculum 'Golden Jubilee' seeds from another generous WSer. I wanted to plant perennials that attracted pollinators so I set the seedlings into several beds that get sufficient hours of full sun that would allow them to thrive. Those plants grown from seed in 2010 are still growing & blooming. Since I didn't know much about agastaches at the time, I assumed it was the species plant but looking back on my garden notes, the seeds were labeled 'Golden Jubilee' which would suggest it's a cultivar. I apologize if I mislead anyone.

It's been my experience 'Golden Jubilee' doesn't suffer no matter what the weather. When it rains, the blooms just look soaked like miniature wet dustmops. The plants retain their form & faded blooms through the winter. If you feel the stems, you'll find they're square, which indicates it's a member of the mint family. The stems & leaves are fragrant as well as the flowers.

CMK - I'd have to second your remark that A. foeniculum is the only agastache that's consistently hardy in my zone.

I purchased & winter sowed seeds of the other cultivars I referenced above. While all sprouted & were planted out, none have proved as hardy as 'Golden Jubilee' altho' while fragrant, they were considerably shorter which at the time was my aim. I got hooked on the variety of bloom colors & differences in foliage types the newer cultivars offered.

While I've had success growing various lavender cultivars from seed via winter sowing, I can't claim success having them thrive for more than 3 seasons running, either in the ground or in containers. It bugs me because I'd hoped to grow it in memory of my mother who loved both it & gardening.

nhbabs - my neighbor has the most amazing clematis that gets all day full sun and NO pampering. It blooms profusely so I'm hopeful that at some point the plants I added to my garden beds since moving here will someday do so as well.

CMK - According to my garden guide (Perennials for Every Purpose by Larry Hodgson), chelone/turtlehead should thrive in just about any soil type, even very acid soil. My soil definitely leans toward the acid end of the pH spectrum. They do prefer moist soil which is up to Mother Nature in my garden--I don't water. I was interested to read that cutting them back by half in mid-spring is suggested to encourage bushier, more compact plants--if I remember, maybe I'll give that a go in 2014. The book makes no reference to soil pH.

Shasta daisies. Any fool can grow a shasta daisy, but for the life of me they WILL NOT grow at this house. Go figure.

Thanks gardenweed, I had the one similar to that years and years ago in an herb garden only it was the plain one with the green leaves, the 'jubilee' is much prettier.

I got the new catalog in the mail today from Bustani's. The have an Agastache 'Bolero' and describe it as:

"18" in height, rose-purple corollas with purple calyces, the thing that sets it apart is bronze tinted foliage. Heat tolerant and moderately drought tolerant" zone 5-10 Its a A. cana hybrid.

I do like that size, some get so big I would have space issues. I noticed this one is available from lots of other sources. I may have to pick up a couple of these this spring and try it out. I need to pre-order early this year, last year we drove up there because they also carry a hardy Lantana called 'Zinn Orange' I wanted badly that gets 40" tall and 60" wide, hardy zone 6-10. They were all out last spring and told me they sell out quick and I needed to pre-order next year.

CMK, I might try that different kind of Lavender, I could probably pick one up at the Midnight Madness sale at TLC in June for half price.

June sounds so nice right now.......

We are in the midst of a severe ice storm right now. I hope we don't get an outage, they predict widespread outages. I am so frightened, one year we lost power for nearly a week and they say the lines are beginning to sag. Sorry to get off topic but I really am very nervous right now. This is our second hit with ice storms this year and its still only December.

Tip on western agastaches and western Salvias with greggii parentage--don't cut them back until spring. Cutting in fall lets moisture enter the crowns through the cut stems. Death to them.

I will add that both my Clematis and turtlehead/Chelone (along with my other perennials) grow fine in my acid, fine sandy loam, though the compost I added to the beds probably mellows it out a bit. My native soil grows wild blueberries and Rhodora just fine, and I haven't added lime or ashes to any of my ornamental beds.

Clematis H.F. Young

CMK - My sumac isn't actually in the bed, it's part way down the hill behind the bed. It's a volunteer wild staghorn sumac, Rhus typhina, suckering madly, but kept sort of in bounds by mowing around the clump. I love the stunning autumn colors, the large primitive compound leaves, and the birds attracted by the winter fruit, so when this one volunteered in such an appropriate spot, DH and I decided to keep it. It isn't appropriate for small properties or manicured gardens IME, but suits the area it chose here on a mown-once-a-year hill, between future vegetable beds, this large ornamental bed and a work area.

-laceyvail, I've tried that before and it doesn't seem to make much difference I'm afraid ;-(

-nhbabs, OH!!!!! See, I go and think to myself that I don't need Clematis and am "over" the fact they won't grow for me and then I see a pic like yours! That is stellar. Clematis seem to do well over on the west side (Seattle etc). They have soil that is a bit more acidic too. Makes me wonder if there isn't something to the acid idea ((acid soil that is, LOL!)).

Maybe I should admit I'm a complete and utter failure with them! I'm a serial Clematis killer ;-( LOL.
CMK

Love that clematis, Nhbabas.

They take so long to get going here.

C. lyonii 'Hot Lips' is long-lived here.
C. obliqua (below: late August) is actually so vigorous that it's a good idea to plant it against a wall to hem it in a bit.

CMK, You are out of the zone 6 or 7 hardiness range for Salvia greggii but I am wondering if you can grow the desert salvias like Salvia dorrii and S. pachyphylla (mountain sage)? They are listed as hardy to zone 5 and grow in rocky, sandy, or loamy soil. I think these are so beautiful. I believe its native to Washington state, all those states far west shows it as an indigenous wild native. I personally think its much more beautiful than any of the S. greggii but its probably because greggii is very common around here while these others seem exotic.

-GP1, I haven't tried either of those sages, though I think I read that the dorii is indeed native around these parts.

I personally don't like the looks of dorii, but I was contemplating ordering the pachyphylla from HCG awhile back but didn't. I just have this bad feeling it wouldn't tolerate out wet winters/springs well!
CMK

Anemones. I can't seem to grow any of them, not the bulbs, not the perennials. I've tried and tried.

In theory I should be able to grow Cleome but have yet to get a seed to sprout or find a plant to buy.

More of a shrub, but I don't know why Strobilanthes dyerianus (Persian shield) is not tried more in 8b. Many others that are reliably killed to ground level are prized, like Brugmansia. In the ground for years now, the only thing that has killed this was weeks of flooding. 3 individuals couldn't live through that.

GreatPlains1-

Is your Chelone in morning sun or afternoon? What kind of soil do you have yours in?

silvergoldenrod, I had never even heard of this plant until this thread came up, its probably one of many on a long list of plants I can't grow. I had to look it up to see what it was.

Anyhow, nhbabs says acid soil which is another thing I don't have.

Maybe nhnabs will post a response. ;)

Sorry. I think I meant to ask SunnyBorders those questions. I saw the picture of the Chelone and for some I thought they were yours.

Silvergoldenrod - My Chelone/turtlehead (though I am not sure what variety since I got it at a plant swap) is in pretty much full sun. It may get some morning shade from a nearby shrub, but it is on the west end of a bed with no trees nearby, and so gets sun from at least noon until sundown. I also don't water this bed unless we don't get rain for at least 3 weeks, but it has added compost plus a good layer of mulch, so it retains moisture fairly well. It is tolerant of wet feet from what I've read, but mine has pretty average moisture and sunny conditions.

Have you tried strobilanthes atropurpureus, Purple? One of my discoveries of 2013 - I love this majestic plant - and also wonder why it is not seen everywhere as it is fairly hardy.

Less keen on S.dyerianus - seen more as a house plant here in the UK.

Campanula, I've not heard of it before, TY. Am I looking at the right pics - it's similar to Nepeta? Do you have a pic of yours?

Sorry SGR, just noticed.

Think nhnabs has said it.

They often list Chelone obliqua (rose or red turtlehead) and C. lyonii (pink turtlehead) as full sun or partial shade. I've had both in both conditions; both in morning and afternoon sun.

They need moisture and I'd assume the more the sun, the greater the need to keep them continuously moist.

Our soil is alkaline, but I've read they'll lake neutral or acidic as well. We have clay, with organic matter added. I've read clay for pink turtlehead and normal, sandy or clay for rose turtlehead, though I'd certainly make sure of organic matter with sandy.

Campanula, I got a young Strobilanthus dyerianus a few weeks ago. I too had only known it previously as a house plant in the U.K.
I chose dyerianus rather than atropurpureus as I hope it will like my climate more.
I am hoping it will grow to about 3 feet underneath the loquat tree. It will only get a couple of hours of sun at dawn there.
Two plants I have trouble with, are Penstemons and Geranium Rozanne.
Reading posts on the Californian Gardening Forum, in theory, they should both be fine in a mediterranean climate.
The geranium just doesn't grow at all. It just sits there all summer and then disappears in winter.
Penstemons, grow and start to flower, then just peter out and die. ????????
Daisy

'underneath the loquat tree'
Sigh....loquats have only recently come to my attention since I had always dismissed them as impossibly tender. However, I am now salivating at the prospect of trying one in a more sheltered area after sowing a couple in the greenhouse. I have read that named cultivars are preferable than wild seedlings (like many fruits) but since they are being grown for those large leaves and lush appearance, I have no concerns about the fruits (unlikely, in any case). I have one sitting outside which has been untroubled by the chill (but as we haven't really had a sharp winter yet, this remains to be seen).
Attempting to grow seeds for 3 completely different areas is doing my head in somewhat - the greenhouse is stuffed but all attempts at rational planning has vanished while I have simply given in to a kind of seasonal madness which invariably strikes during the dull dark months - a guilty attempt to actually sow all those seeds I have collected, hoarded, stolen even, during the short days of autumn as insurance for a bright spring and summer. Obviously, if every smidgeon of space is already used up by trays and containers, there is going to be a reckoning when all these seedlings need pricking out and potting on.....but I am denying reality in a haze of horticultural craziness.
I am mystified by your geranium problems, Daisy. True, Rozanne vanishes down to an absolute minuscule crown....but then roars into life (quite late in May), growing to a ridiculous size in weeks. Penstemons......have you thought about some of the species rather than the large flowered types? Have a gander at Plantworld seeds - I think Ray keeps a good selection....and avoid the miffy Husker's red. Also, I find the fat leaved ones to be a bit rubbish for me (although shouldn't be so much of a problem for you) but they are not really resistant to drought. If you are keen on that trumpet shaped flower, have a go at incarvillea - there is a lovely easy annual (incarvillea sinensis) as well as a rather interesting woody version (I.olgae - taller than I.arguta but with better proportioned flowers).

Campanula, I wish I could send you some of the loquat's fruit, when they ripen in May. They are delicious.
When I was first viewing this little house, back in 2008, the tree was full of fruit. I managed to hack my way through the brambles and tree saplings to sample some. Oooh! the juice just ran down my chin.

Why oh why didn't I think of Plant World Seeds? When I lived in Cornwall, they were only in the next county and I used to go there sometimes and wander around the "world".
I have just had a quick look at their web site.Do you realise
that they have 42 varieties of penstemons alone?
Good grief. What a wonderful dilemma, choosing from them.
At the moment, I have the same problem as you have, only not on the same scale. Seed trays everywhere. My husband is complaining that he can hardly get into the shed anymore...and this is before they are pricked out.
Mind you, if they all germinate, I won't know where to put them. My tiny garden is already full.

I used to grow Incarvillea delavayi in the U.K. I didn't know about any other incarvilleas. Thanks for telling me about them. I will have to do a bit of research.
Daisy