Perennials not Annuals

How often do we call a half-hardy perennial an annual? We mostly treat each in the same way, because neither returns the following season (I am in zone 6). But there are hugh differences. The annual can not, in any manner, be coaxed into returning. It has grown from seed, flowered, and died. While the half-hardy perennial will die if it is exposed to frost; it can be kept alive through cuttings and the storage of bulbs. So many of these half-hardy perennials we call annuals can be grown on.

Some examples:

Helichrysum petiolare 'Variegatum'
Impatiens balsamina
Lablab purpureus
Lantana camara 'Mozelle'
Lysimachia congestiflora 'Outback Sunset'
Pelargonium quercifolium
Portulaca
Solenostemon scutellarioides
Tagetes erecta
Verbena speciosa 'Imagination'



Other examples:

Canna glauca 'Panache'
Guara lindheimeri 'Dauphin'
Salvia leucantha
Salvia mexicana 'Limelight'

Each winter I tell myself there is no room for a lot of cuttings. But each year I grow them. Either because the variety or cultivar is hard to find, or the cost of buying more plants is outweighed by the savings in money.

Hi, Golddog. I just noticed this thread in the Annual forum and thought it was worth bumping back up. I think we've been neglecting this forum of late! Yes, we grow many half hardy perennials as annuals... in fact, we grow many hardy perennials as annuals.

For instance, I love hollyhocks, but they are biennial and don't winter over here. I've tried "Summer Carnival" that is supposed to bloom the first year, but not here! Finally, I found that the Malva sylvestris will bloom quite nicely here the first year, but don't winter over. They've become one of my favorite "annuals"!

I would like to add Artemisia 'Powis castle' as a hardy perennial that can be tempermental and not return in zone 6 and below. I never hesitate to pull it out in the spring if there is any chance of it not making it. Although it can be late. This plant is very crucial in my scheme of combinations; a great plant to play off of. A near-by nursery winters them over under cover, so I can always find one that is mature and early developed. A. 'Huntington' is supposed to be a bit hardier; I am still expermenting with it.

Yes, I bought a Powis Castle about three seasons ago, & it comes back each year, sorrier than the year before, and it is always late. Maybe I should just consider it an annual and plant it every year.

When in the ground from the previous season, A. 'Powis Castle' takes for ever to grow to the proper size. August is when it starts to come on. The more I think about it, the more I am going to buy it each year. I hate to wait that long for stability.

By August, my summer is just about over!

Weez, it looks as though you really can not do without a greenhouse. You need that good start in the beginning of the season.

One persons perennial is another's half-perennial, depending on the growing zones. I just thought it important to know the half-perennial can be 'wintered' over.

My snapdragons did not die last winter. I just cut them back and they came back great this year.

Aren't they annuals??

Well, Evelyn, I think that is the point that Golddog is trying to make. Many annuals are perennials "somewhere", but many of these plants can be used as annuals "elsewhere". I think the tricky part is determining which perennials can be treated as annuals, and of course, that requires that they bloom the first year, or there wouldn't be much use in growing them!

When you buy greenhouse plants, they've often been started months before we buy them, such as Pentargoniums (geraniums). For those of us in colder climes, they are a one trick pony, unless we cut slips or winter them indoors in a cool spot. For others, they are a perennial.

I have to say that I've never been clear on the definition of a "half-hardy" perennial or a "tender" perennial. Are any plants truly annuals or do they just have a short life span? Golddog has brought up a pretty good topic here. Hopefully we'll get some of our Garden Gurus involved here.

I can't seem to find an 'official defintion' for half-hardy perennial.

"Living for more than two years, and usually flowering each year from the second season. Cannot tolerate frost, but may be over wintered if given frost protection". (tender perennial) Thompson and Morgan

I am going to stick with this as it is easy to understand. According to "Botanica" Antirrhinum include annuals, perennials, and evergreen shrubs. The common snapdragon (Antirrhinum majus) is a perennial but is normally treated as an annual in gardens.

Other thoughts are surely welcome.

OK, I've looked it up, too, and I got the same info for perennials and half-hardy (tender) perennials, the only difference being whether they can tolerate frost or not.

T&M also lists "annual" as a plant that completes its entire life cycle (growth, reproduction, death) in one season.

Biennial has always been a little unclear to me. T&M lists biennial as "A plant that completes its entire life cycle in two years, growing in the first, reproducing and dying in the second." That seems pretty clear, but what happens if a biennial doesn't bloom the second season. Does it continue to come back each season until it does?

It really all boils down to the expected lifespan of a plant. I guess an annual's life span is a year, but how long can a perennial live? When we get old, we start to fail, then we expire. Do plants do the same? I've never heard anyone say, "This delphinium is getting a bit long in the tooth, time to get another."

True biennials do only live for two years, if they haven't flowered and reseeded by the 2nd year then nothing doing. However, some plants grown as biennials are actually short live perennials and will sometimes go for a 3rd or 4th year.

Some perennials can live for a suprising number of years others live for just 3 or 4, it all depends on the plant.

Very often a clump or tuft forming perennial will show it's age by dying out in the middle but the plant around the edges is still very much alive. In quite a number of cases, division every 3-5 years is essential to keep a perennial plant fresh and growing strongly. Also if you leave the dead crowns they can pass on disease in their dying stage and habour pests well beyond shuffling off of mortal coils.

Older plants will often have fewer or no flowers (going blind) but continue to produce leaves for a few more years. Immunity to various diseases will diminish as the years go on and sometimes the plant will just peter-out and die for no apparent reason.

No different to any other living thing really

Thanks so much, Baa. That explains it quite nicely. Now, if MaVieRose would show up with one of her links for a site that give information on the average life expenctancies of different plants, I'd have a much better understanding of my green wards out there in the yard... turning to brown little wards, right now, actually!

Well, I'm glad I finally divided my dicentra spectabilis last year. I left half the plant, digging up the other half. By the time I finished, I had another large plant for another bed, as well as 26-gallon pots to sell!

How interesting that plants "go blind"... yes, I've had plants that seem to quit blooming, and that explains it. Most of my plants live quite awhile it seems... perhaps our cool moist summers are kind to them.

WZ

There are really no set ages for plants to die in the perennial section. Besides if you divide most them every few years you can extend the life of the plant by quite a few years.

Not all perennials enjoy being divided and transplanted, Peony and Oriental Poppy don't do so well as others (although they do last quite a number of years in one spot anyway) so it might be worth looking for perennials that prefer to be left alone rather than for the age of perennials.

OK, if a plant can be divided, are the new growth chunks truly the original plant or new plants still attached to the original plant? Does that make any sense?

So, concerning those plants that do not divide well, a better approach would be to determine the approximate life span of that type of plant, watch for signs of aging, and begin grooming a new plant from cuttings, etc. to take its place. Does that sound logical?

I have an oriental poppy that is probably 8 years old. It still seems to be vigorous, blooming profusely each year. How many more years are conceivable for this plant, do you think? Can one even estimate?

I think your questions are questions for a botanist. Although, it seems roots several years old might lose their ability to function. Divisions would allow for new roots to form. My theory is that the roots age to a point where they no longer function properly.

What about perennials in warm climates that don't lose their leaves and continue to grow year round? Versus perennials that die back each year? Which one will live longer? I wish I was still taking Botany with my dear friend, Sister Mary Joy. She would have an answer.

WZ

Its a bit like the allegory of the old broom.

A friend of the family once told us he has had the same broom for 30 years. Over time the bristlehead has been replaced several times, every now and then it gets a new handle but in essence, to the owner at least, it's the broom he has had for 30 years.

As for perennial plant life expectancy, it all depends on growing conditions and care. Yes, it's perfectly logical to look at a plant and try to approximate when to make more clones of it. However, life expectancy lists are difficult to find, best to just to propagate, give them to friends and if your plant doesn't survive the one year, they can return the favour if you have run out of plants *G*.

For those plants that dislike disturbance, root cuttings are one of the easier ways of propagation, as they are taken when the plant is in it's dormancy.

Golddog

You are correct that roots lose their ability to function with age but a healthy plant will continue to grow new roots throughtout it's life.

As for those plants that can be evergreen/semi-evergreen or hebaceous/deciduous, it really doesn't seem to affect the plants age to a noticable degree. However, plants that are mainly herbaceous or deciduous always appear to me to be fresher and more vigourous than those that don't lose them.

For me many things are perennials, but some times, getting a new plant is fresher and more alive looking. Also everything gets fungal and then needs to be replaced, after about a year. Monkey Flower however, just keeps going year after year. You can cut it back, and then it will fluff out again.

I have seen these two plants Peony and Oriental Poppy live in the same place without being dug for thirty years or more
thats not saying it is the same plant I'm sure the roots have growen and died in that time but it looks same and blooms every year

An annual is a plant that dies after it matures its pre-determined number of seeds, or when growing conditions cease to be favorable. In other words, a corn poppy (annual) will keep flowering, as long as it is deadheaded until either cold kills it, or until it is dug up.

A perennial is just that: perennial. The named cultivars that we all grow are, in essence, the same plant. So how long a plant lives depends on when the last remaining cultivated plant in existence dies. In some cases, this may be hundreds or even thousands of years (in the case of some Japanese-grown plants).

'Tender perennial' is a somewhat meaningless term. Since the world is made up of innumerable climates, "tender" in Miami, FL would mean that when the temperature goes below 40 the plant will be damaged. In the mid-west, 'tender' means it is unlikely to survive a typical zone 5-6 winter outdoors. In interior Canada, 'tender' would mean things that easily survive in zone 5. Generally they refer to plants that do not survive freezing (or slightly below freezing) temperatures for more than a brief period of time. Pelargoniums and petunias are good examples.

There are many perennials commonly grown in colder climates that require a dormant period. If one is not provided, either the plant will die from growing too much or will not set flower, although it may live for years.

Also commonly grown are plants that are called "winter annuals". Some of the worst lawn weeds are in this last category. Seeds sprout in autumn, remain seedlings until very early spring, when they burst into growth, flower, set seed and die within a few weeks. A few garden flowers can be in this category, also: in my climate, nigella, larkspur and annual poppies work best if grown as winter annuals.

Then, of course, the plants that struggle and die in warm climates: pansy immediately comes to mind. They happily grow and flower most of the winter, but when hot humid summer comes, they promptly die. There is no recognized category for these types of plants, but "cool-weather flowers" has been suggested most frequently.

Climbing down from the podium now... *grin*

Good Speech, you're welcome at the podium anytime! I have a question about your second paragraph. Are you referring to the life of that species or the life of one actual plant. As both Baa and Dave pointed out, the center of a plant may die, but new growth will continue, thus the plant lives on. It seems you are suggesting that a perennial lives as long as one of its species is in existed on the earth. Am I getting that right?

Also, I'd like to mention that in my wet zone three climate, winter annuals are not much of an option. Tender young seedlings will not survive the winter, though seeds that are self-sown may sprout in the spring.

And the more years I garden...the more I tend to think that Annuals are just tender perennials!!!! E.

Named cultivars of a specific plant are what I meant when a plant can live for hundreds or thousands of years. Offsets are still part of the original plant. In that sense, "perennial" means that it will live for a very long time.

Other perennial plants that are grown from seed and never propagated can have fairly short life-spans (think columbine -- they typically only live for a couple of years).

The generally accepted definition of a perennial is a plant that is either herbaceous or deciduous that lives for more than a year. Scientifically, more and more botanists are moving away from accepting "biennial" as a classification. Many of the so-called biennials are really short-lived perennials. Formation of seed seems to be the true qualifier as to whether a plant lives after seed is set. Some "perennials" die after forming seed. Angelica, foxglove, sweet cecily all are notorious for this. It may take a year after germination, or it may take 2-3 years after germination for the plant to form enough seed that it figures its life's work is done and it is time to let the kids take over *grin* Some botanists are theorizing that is the limiting factor in a plant's life-span. Maybe that is why certain plants that are notoriously short-lived can be made to thrive for years beyond their normal life-span. Meconopsis, edelweiss and similar plants, if they are prevented from flowering in their youth, can be made to live for many years (without propagating by cloning -- dividing).

True annuals are very seldom grown in US gardens nowadays because they transplant poorly (usually), they don't bloom while in their market pack, and have a fairly short life span. Most casual gardeners do not start plants from seed, it takes people who want to move beyond buying a flat of flowers at the local hardware store to pretty up the yard.

A few hybridizers have worked to come up with annuals that are sterile, and thus will live and bloom for months to help overcome the reliance on the "tender perennials" that are mostly sold for annuals (begonias, impatiens, pelargoniums). I have seen zinnias, marigolds (the famous triploids that don't need to be deadheaded), and nemesias all developed for this. Many, many more are being developed. Maybe sterile poppies that we can have blooming for 5 months??? How about sunflowers that will? Or sweet peas. Hopefully some of the more obvious shortcomings in previous years will not be overlooked. Sweet peas without scent are horrible, I think that led to their downfall; many of us will deadhead pretty regularly for plants we really love. Imagine poppies without their feathery pistols and stamens? That would be a true abomination!

And I never even mentioned another plant classification: the "semi-woody" perennial. They are also referred to as "sub-shrubs" like Russian sage, lavender, and rosemary. Again, they may be deciduous or evergreen, but their common characteristic is that they all develop stems that become woody with age, yet can be cut to the ground and will grow new stems from the roots. Are they shrubs? Are they perennials? They are both. Yet another area that botanists are currently disputing, leaving us poor gardeners to try to figure out what, if anything, to do about it. Mostly, I just sit back and wait until there is general agreement, then keep on growing the things ;D

(Can you tell I used to teach? It is a whole lot easier to do so while sitting at my computer, rather than standing in front of a group of people sitting at theirs! No, I never professionally taught plant classes, just computer classes.)

I like the 'biennial' classification, which to me means a plant which typically forms a rosette of leaves the first year, which extends and blooms the second year, before going to seed and dying. The terms annual and perennial have their true scientific meanings, but often it is a matter of how the plants are used in the garden, i.e. does it 'come back'.

OK! My snapdragons are going on their third year! Are they tender perennials?? They have lived through the frosts and snow where the purple fountain grass and other tenders have died off. ALL the catalogs list them as annuals.

I have cut them back. Maybe they were biennial and they didn't have any babies, so they lasted longer???

Evelyn, the common snapdragons are perennials, but are so prone to disease that they are usually treated as annuals. Mine bloom best in cool weather: they bloomed until early January this year (they are currently buried in snow so I don't know if they still are). Last winter they didn't miss a beat until hot weather set in during June. Drought did them in in August. New ones sprouted in September, they started blooming in November.

That is great that yours are still going strong! You are definitely doing something right to keep them so healthy!

I've never tried to winter over snapdragons, but you'd think I could do it if they like cool summers. I don't think our winter temps get down as low as yours, Lupinelover.