Mathematics don't belong in my garden :) Way too overcomplicated. I plant what seems good, and plant more of it if it works for me.

I choose long-bloomers like Coreopsis, BES, Becky, veronica, etc. With this crazy weather things seem to bloom whenever they like anyway (my lavender just started to bloom again).
I don't much bother with very early bloomers in the back yard because no one goes out there before May anyway. Some bulbs and anemones in the front yard is all I time for Spring.
The only thing I need in the fall for sure is Sedum Autumn Joy.

I tuck in some annuals (zinnias and double-impatiens) for season-long color. I put in some golden oregano this year and, boy, what color!
And so, with all that, I don't give any thought to how many of what kind I need. Then again, in this cottage garden, I have a gigantic cherry tomato in the south-facing perennial bed, so anything goes :)

Huh? Never heard of that one.

The advice I think is great is to plant for the season(s) you will be planning on enjoying. Example - if you're away a lot in the summer (lucky you up there at your cabin on the lake!), then you wouldn't want/need a lot of summer bloomers.

Planning my first mixed perennial garden from scratch last year, my focus was on drought tolerant, cold hardy, sun loving perennials in colors that would work well with the strong color of our house. I think I DO have more summer and fall bloomers than spring, but I didn't really plan it that way. With our tendency to get late frosts and/or snows, there isn't really much point putting in a lot of spring bloomers here. I did get a little antsy to see some blooms, other than bulbs, by late May, but by June things were really taking off.

WELL, I can answer this. Because I think I was one of the primary people who quoted this "rule" 5 or 6 years ago on these forums. And it was an adaptation of a rule I read in an article by Christopher Lloyd in Horticulture "The secrets of a long season border", from 20 years or more ago.

And for me, it was an article that I saw after I had been gardening for a number of years. I had enjoyed my borders full of bloom in May and june. Then the wilt started, the penoies with blight, the columbines with leaf miner. A perennial border that looked downright awful on August 1st, even when the local weedlots were full of monardas, goldenrods, asters, grasses, and beat my perennial border to heck.

SOOOOOOOO.....

I started looking for plants which bloomed mainly in August and September. Others as late as October, others in July. Many many fewer June bloomers. I went for geraniums, baptisias, catmints, things I really loved that bloomed in June. Mosy of them also either bloomed in later summer too or had great foliage and form which last through the season. One of the biggest "keys" to success -- clematis. Among the best of "perennials", many with very long seasons, add height and interest to an otherwise flat border landscape.

Yes, compared to some gardens, my gardens are a tad less 'bloomy' in June than an average Michigan garden. But it is really amazing how little bloom is needed to give the effect of a flower garden, especially when the form and foliage of phlox, persicarias, veronicastrums, crocosmias, asters, grasses, and sedums contributes so much to the effect of the garden long before they bloom. Yes of course, long bloomers are a key. And no, if you travel to your cottage in July and August and you just love bearded iris, NO, you should not plant that kind of a garden. Plant your bearded iris and dance for joy!

But for me, I was amazed at the staying power of a late season garden. A garden which has a spring splash with bulbs, the fullness of June with a few wonderful vignettes of geraniums and catmints and roses, and then packs a wallop from July through October with all the plants, many originating in N America, which have peak bloom in that period. As for me, I love a garden which has a major flush of bloom in September. In the N temperate climate of E North America, September should be one of the heaviest blooming months of the garden year.

For gardeners who might want to read more, read "The Garden in Fall" by Allen Lacy, and "A Year at North Hill" by Winterrowd and Eck. Both show the power of the garden which has long season interest but which has a major peak in the late summer and fall.

Woody plants, with their berries and fall color following early season bloom, are major components of this type of garden too. In fact, the backbone...

Well, I never heard of the rule, but it sounds pretty good - although I have to admit to maybe wanting more spring bloomers. But then again, that's probably why I seem to have such a hard time getting late summer/fall interest in my gardens. I think about it and think I've added stuff, but it's still not quite enough.

I've just finished planning a bed for a friend in a very wet area, and will begin to bulid and amend it next week. After lots of research and reading, we've selected our plants, and I have to say, I am most excited because lots of them have great fall and winter interest. It might be too early to praise this garden yet, as it's not even planted, but I guess there IS something to be said for planning. I should try it more often, lol!

:)
Dee

Another way to "cheat" besides using Clematis is to use lots of bulbs, particularly lilies, which don't take up much room.

I remember that article form Horticulture! I think I still have it somewhere...
I do like the fall garden (even though fall is my least favorite seasons). The cooler weather and bright blue sky of fall days (like today) really makes me want to be out in the garden again after all the humidity and hazy days. Plus the colors really get much more intense as the nightime temperature drop.

Here's how I "cheat". I avoid planting and planning only in the spring and winter.... in fact I don't plan too much, I just plant whatever I think will look nice in that area. BUT in order to compensate for this I take a look at the garden each week and make changes.... if there's not enough color to make me happy I head out to the garden center and see what's blooming there that I could add. Right now I'm slightly tempted to rip out an iris or two to make room for more asters... That would never happen in June!

Just make sure you go to a reliable garden center. If you go to one of the box stores you might just end up with some cheapie plant that looks good on the rack but (1)doesn't really flower at that time since it came from way out of state or (2)insn't really adapted to your area..... I seem to run into these two problems when I look at their selections this time of year.... not a single AJ sedum, only a few beat up ornamental grasses, but tons of coreopsis, florist mums and some asiatic lilies that normally bloom in June.

Come to think of it I think I need to go to the garden center anyway (just for a peek). I can look at the paperbark maple that I'm too poor to buy, check out their jap. anemones and maybe take home a few new daffodils.

It's not hard to get early flowers (bulbs, creeping phlox, euphorbia polychroma) and June flowers (roses, iris, lilies). But July and later takes planning. Phlox are helpful. (David is still flowering because I cut half of it back in July) and the asters are now coming into bloom. And chocolate eupatorium. And the Japanese anemones. And more roses. And geranium Rozanne is still going strong.
And no, I'm not into arithmetic, much less math.

As we have an endless winter, I need lots of spring bloom. I only have a few summer and fall bloomers. I fill in by having spring plants that have good foliage e.g., peonies, siberian irises, geraniums.

I have also underplanted bulbs. I planted tulips about 18 inches deep and planted chrysanthemums on top. Daffodils went under hostas. And so on.

My spring bloomers are crocuses, daffodils, tulips, pulmonaria, heuchera, lilac, irises, peonies, lily of the valley, hepatica, and trillium.

My summer bloomers are coreopsis, geranium, daylilies, hostas, roses, heliopsis, ligularia and echinacea.

Fall bloomers are actaea, chrysanthemums, late blooming hostas and reblooming irises.

How do you underplant? Do you plant right on top of the bulbs and do they grow right through the other plants? Sounds interesting!

I pretty much garden according to the 1/3, 2/3 rule that you cite, although I've never counted up the plants on both sides. LOL. My zone is so much colder that I don't know if I can give you enough specifics to be helpful for you.

My garden goal has always been to get the absolute most out of my rather short growing season. I aim for a seven month garden starting about mid-March and going to mid-October (that probably seems pretty short to you in zone 8, but it is really stretching the season here). I also try to keep the long dreary winter months from being too stark as well, setting up a couple of spots of sedum, grasses, & evergreens that I can see from my windows during winter. I think I have accomplished my goal quite well, with a well-balanced garden that looks quite lovely through seven months and often beyond.

Books that have been helpful to me include Ann Lovejoy's The American Mixed Border: Gardens for All Seasons (and many of her other books as well) and Pamela Harper's Designing with Perennials. Both of these author's are from warmer climates so you would be able to use a lot more of their plant selections in your garden design than I can.

I rely heavily on the mixed shrub border approach. My season starts with as many bulbs as I can squeeze in (in specially created spaces) on my inhospitable soil (very dense wet clay) and a nice variety of spring blooming shrubs. I also use a small variety of spring &/or woodland ephemerals, such as Virginia Bluebells & Bleeding Hearts. The main spring perennial that I use with bulbs is Sweet Kate Tradescantia (spiderwort) for its chartreuse color. These are followed by a few bearded Iris and lots of Siberian Iris (long lasting spiky foliage) and Lady's Mantle (wonderful spring chartreuse flowers and interesting all season foliage). I also have a small raised gravel garden with spring alpine and various small trailing plants and a small woodland type garden with May Apples, trilliums, gingers, foam flowers, shooting stars, lots of minor bulbs, and columbines, which are later overtaken by large hostas.

Evergreen shrubs are quite limited here in zone 5 compared to what you have available to you in zone 8, but I use what I can of them in my small yard, varying colors from dark & light greens, mixing shiny and dull textures, and addding spots of golds & blues. I also fill in with shrub size perennial grasses which stay up through the winter.

I also try to use only shrubs that have multiple seasons of interest (one exception is Miss Kim Lilac). I'm talking about shrubs that have spring blooms and good fall color or berries, such as viburnums & aronias. I also use quite a few summer blooming shrubs as well, such as Itea (glorious long-lasting fall color) and Clethra (sweet flowers and likes wet soil), as well as Cotinus and Physocarpus with all-season lovely colored foliage.

I garden on a rather small scale, a small suburban lot with more house than yard, but I use all sorts of perennials (my Excel chart lists around 275 individual types of plants, not counting 125 daylilies, 25 clematis & 50 hosta). Most are in the bays between shrubs and around and in front of them as well, along with two beds that are primarly perennial, with just a shrub or two.

With this many plants in such a small amount of space, you can imagine that my garden is very heavily layered and that I depend on spring ephemerals to fade away to make room for bulging summer plants & that I cut back many perennials and shrubs quickly and heavily to show off the plants that are just coming on. I rely heavily on plants with a long season such as coreopsis, sedums, catmints & grasses and have a long list of late blooming plants (see my recent postings to the strings on fall plants for some of them).

I still have rebloom on some phloxes (5 varieties, all blooming at slightly different times), catmints, sedums, some clematis & a couple of daylilies, along with one helianthus (First Light) which has not yet bloomed. Sweet Caroline Hibiscus moscheutos is still in bloom (started in August) and most of my grasses are in bloom with the exception of Miscanthus sinensis Strictus, which sometimes doesn't make it to bloom before hard frost, but is colorful enough by itself, as is the tiny Sedum sieboldii (October Daphne) which seldom blooms for me either (only in long warm falls). In summer the garden is mostly full of daylilies of every color size and shape. My daughter says it looks like Disneyland then. A wee bit overdone, I think, but I love it. The late bloomers take over next, accompanied by things that never quit like Rozanne geranium and Knockout Roses.

I cheat a bit too on the daylilies that start looking shabby late in the season, by planting a big, always good looking, Baptisia in the center front of the main daylily bed. That, with a couple nice container plants and two large Sweet Autumn Clems in their full glory along the nearby fence, blinds you to any garden messes.

P.S. If you are interested in pictures, please check my postings &/or homepage. Best of luck to you. Leslie

I am learning so much! Thank you all for the good ideas and Yeona for starting the thread!

Leslie, I looked at your lovely photos on your page. Everything looks so neat. How do you manage that?

Lots of shrubs, good edges & most importantly only take pictures when things are looking good! LOL.

LOL

I see your list of shrubs posted above. I just noticed you mentioned another posting on late fall plants. Going to check that one out too.
Thanks again,
VG

I know too many gardeners who complain that their gardens poop out after June. One problem is that the early blooming plants nearly all bloom for only two or three weeks while there are summer bloomers that bloom for two or more months. To try to have lots of continuous bloom in the spring it is easy to fill the beds and have little bloom for the rest of the season. For me it helps to plant bulbs at the back of beds where their dying foliage is hidden as the perennials grow taller. The majority of the my late spring blooms are chosen for summer long attractive foliage like baptisia, peonies, siberian iris and amsonia. I plan the garden bed for the attractive balance of their foliage throughout the garden as well as their bloom. A lot of the long blooming July and August plants are stalk shaped like daisies and phlox and they look well with some of those foliage anchors from spring bloom. I hate to have the garden end so fall flowers are really important to me. Many of them like asters and boltonia are easy to squeeze in throughout the garden waiting to take center stage as other plants fade.

I've always liked the August to October period in our gardens and seemed to have gardened by this 'rule' as I look at all that is blooming well even in late September. Purely by mistake mind you.

One area which I adore right now is blooming with Phlox David and Orange Sensation, Cimicifuga Brunette at 9 feet tall, Eupatorium Rugosa at 7 feet tall, Blue Aconitum at 6 feet and a Ville De Lyon Clematis bursting in flowers on an adjacent veranda. Don't know what I was thinking when I did this garden bed but it sure smells and looks grand!

This is a super, super thread! This "rule" really is a good one and does keep your borders looking great all year. My gardens get an extra lot of attention in the fall because so few gardens look even presentable at that time. I agree with all that has been said, but here are a few other tips.

I include some annuals in my beds, particularly on the front edges (at least 3 and often 5-7 of a kind planted as a clump). They get going fast and fill in bloom gaps as the perennials are getting some size and preparing to bloom (or ending). The majority of my perennials do bloom in late summer and fall, so the annuals are extremely valuable early on, which is when they are at their best. Later, the perennials can carry the show and I pull out the annuals that are looking ratty. Bulbs are so important in the early spring, but can be tricky too. It's all too easy to dig them up and damage them when dividing perennials, so I try to use them as underplantings under shrubs. Someone asked about that. When I planted my roses, I also planted daffodils about 4 to 6 inches apart in the area around the roses (right up to the root ball) that would represent their mature canopy. I did the same thing with leucojum under hydrangeas. You can do this with almost any deciduous shrub, and this way the bulbs fill in interest when the shrubs are bare, but the awakening shrubs hide the rotting foliage of the bulbs later on. I am thinking of adding a few large pots to some of my borders this year with layers of bulbs in them to give some further early spring interest.

Anyway, back to the rule. It does require some advance planning to do it this way, and although I know there are those blessed people who are so creative they can garden by the seat of their pants, for me, some graph paper, a pencil and some time spent planning never fails to pay off.

I have not considered this particular rule to begin with. Most important question you have to answer for yourself is what are you trying to achieve? If you have several B-days and anniversaries during June and spent your vacation at home at that time- by all means, pack it up with June flowering beds and make most of it.
Some people do spring beds, summer beds and fall beds and plant them accordingly so they show best at certain times of the year.
My rule is every flowerbed has to have at least one point of interest every day of my gardening season from early spring into late fall. It starts with snowdrops mid Feb and ends with fall crocuses and cyclamens. Lots of small bulbs could be double and triple planted in same spot as your other perennials and give your extra season of interest.
I even go as far as to plant fall blooming japanese anemones squished next to early blooming columbines- I cut foliage from columbines after the bloom and let anemones start their show.
Clematis will pick up a lot of show and take minimal space so going vertical is essential if you garden on small plot.
One more thing to remember is that plants that bloom early go into decline early so garden starts looking ugly and yellow. the more fall/late blooming plants you have the longer your garden going to look good.

I'm sorry to see that someone has tried to codify advice about planning for late summer/fall garden enjoyment with a rigid rule. I'd never worry about counting plants in this way.

I do like building anticipation as fall approaches by incorporating late-blooming perennials, ornamental grasses and colorful (via foliage and fruit) shrubs into beds and borders. The two books that David mentioned are excellent sources of inspiration.

Weirdly though, the coolest thing in my garden right now is {{gwi:270982}}.

I had vaguely heard of this rule before, but had since forgotten it. I was very happy to be reminded of it again. I didn't take it as a rigid rule, but a direction to go that had merit. If you have a lot of late bloomers in your garden, not only will you have a super looking fall garden, but those plants that haven't bloomed yet all spring and summer I would think would be looking very good all season.

The guidelines I usually use to guide my plant selection are normally low maintenance, long bloom, and that has helped me to avoid many potential problems and to have something blooming most of the time. I think keeping this idea in mind will also be of value to me. I have already planted asters, chrysanthemums, hibiscus, grasses, sedums, cosmos...and btw, Delphiniums are reblooming very well right now and that would make them a double duty plant, having bloomed in the summer too.

I didn't read all the posts, so please excuse me if I repeated what was already said.

:-)
pm2