Coreopsis 'Mercury Rising', which began blooming some weeks ago, and other of the 'Big Bang' series of Coreopsis will bloom until fall, as will some Geraniums--'Dilys' --and will tolerate full sun. However, anything you plant now is unlikely to look impressive this year--bad time to plant, perennials need a year to settle in, etc.

Most perennials bloom well for two weeks to a month than move on. One needs a variety if one wants color ALL _______(summer/fall/season).

For season-long bloom, you need annuals or else a wide variety of perennials. Kept watered, annuals are blooming machines. Perennials have cultivar-specific bloom periods; i.e., Hellebores/Lenten roses bloom in my Z6a southern New England garden beds March/April; daylilies offer blooms July/August as do Platycodon/balloon flowers. Hardy hibiscus is another late-season bloomer as is rose of Sharon. Aquilegia/columbine blooms in spring; Tricyrtis/toad lily blooms September/October. They're all growing--together--in my perennial beds. I planted a pretty wide variety of perennials deliberately to provide season-long blooms that make me smile as well as to sustain pollinators.

Gaillardia blooms mid-late season, Verbena will bloom all season if kept trimmed back, Astrantia major, Garden Phlox bloom late-season/fall as does Chrysanthemum. Check out The Well-Tended Perennial Garden at your local library for additional season-specific information.

Of all the different hydrangeas I grow, in particular, Hydrangea paniculata and H. arborescens cultivars will have the most bloom at this time of year. My paniculata types start blooming in late June (Quickfire) to late July (Pinky Winky) and bloom until frost, 3-4 months. Bobo and Limelight are two other commonly found varieties. My H. arborescens Annabelle starts in July (when depends on how hard she was pruned) and continues putting out new flowers until September sometime.

Helenium 'Mardi Gras' blooms from early July until late August, and other varieties are starting blooming now and will bloom for most of August in my garden.

Cardinal flower is blooming now here and will continue well into August.

There are a variety of Clematis that will bloom for some of that time. For instance I have Mikelite, Star River and John Huxtable blooming now and some of the May blooming (type 2) hybrids will bloom again in September.

My 'Major Wheeler' honeysuckle (Lonicera sempervirens) has a really full flush of blooms in late spring, but continues blooming on new growth until hard freeze. The hummingbirds love it. Major Wheeler and Daphne x transatlantica 'Summer Ice' are the two longest blooming plants I've grown, and while Summer Ice doesn't have spectacular flowers, it blooms from May until hard freeze and they waft scent. It has lovely variegated foliage that will be evergreen for you.

I have orienpet (oriental-trumpet hybrids) in full bloom now, but you are earlier than I am (80 miles north of Boston) so they might have gone by in your area.

Late daylilies will bloom well into August here. I rarely keep track of the names of mine, but the daylily forum may have suggestions of late bloomers.

There are a lot of fall blooming asters, but look for ones with mildew-resistant foliage, just like for the tall Phlox.

Some of my favorite small shrubs are Caryopteris, with either gray or gold foliage and blue flowers in September. There's also a related herbaceous species, C. divaricata 'Snow Fairy' which has variegated foliage and blue fall flowers, though the foliage is really the star of the show.

My red hot poker plant (Kniphofia) is starting its repeat bloom now and will continue much of August.

There are many fall-blooming monkshood (Actonitum), and though it's quite toxic to consume and you shouldn't handle it without gloves if you have open cuts, it's got beautiful flowers and foliage that is always healthy in my garden.

Salvias (many varieties) bloom very well when temps get cooler. Mine put on a great show in spring, sporadically in the summer heat, then get their second wind in fall. Great, dependable plants.

I'd underline arcy_gw's comment, though we might say for average bloom time here, 2 to 3 weeks.

Not precisely "keep their bloom"; however, something that extends bloom time in many key (for me) perennials for a mixed perennial bed is deadheading. Try the "Dundee Fact Sheet: Deadheading Your Garden". The company is located in Plymouth. Mn, but, in my experience, the information is good for gardeners here as well. Admittedly, the first bloom is normally the more showy.

Below: the same two Phlox paniculata 'Pina Colada' on July 17, July 26 and September 28 (latter second blooming) last year.

I have several perennials that bloom spring/summer/fall for me especially if some moisture is kept available. Most are native plants.

Lantana, Hesperaloe, Blackfoot Daisy, Salvia greggii, Calylophus drummondii (bush primrose), Russian Sage, Wild Four O'clock, Stenaria nigricans (Prairie Bluets aka Diamond Flowers), Dyssodia acerosa (Fetid Marigold aka Dogweed flowers March to December), Missouri Primrose (Spring -Summer), Sideoats Grama, Fallugia paradoxa (Apache Plume), Sphaeralcea angustifolia (Lobeleaf Coppermallow), Blue Grama (Blonde Ambition is particularly ornamental and nice).

I have a quartet of stalwart, guaranteed long bloomers but suspect hardiness might be the kicker for you - alstroemeria, shrubby salvias, perennial wallflowers and anisodontea El Royo, along with helenium 'Sahin's Early Flowerer, will bloom continuously throughout the summer. Add in the small shrub rose, Sommerwind (a truly continuous bloom machine), for a symphony of pinks and reds which will keep going until late October.

perennials... regardless of bloom time.. should have been planted in spring ... to grow the roots.. to make it thru the heat of summer ... to bloom in fall ...

planting such now.. or in a month.. may or may not get you bloom in fall ... mostly because you cant find a lot of the options ....

obviously .... things like fall mums.. are available in the bazillions in fall ... but not all of them are fully winter hardy.. depending on location ...

regardless of all that ... now is a great time to ask.. since peeps can look out the back door .... and give you lists of plants for next spring ....

ken

I agree with Ken. The challenge of planting them now would be just keeping them alive and people either tend to overwater or the soil balls dry out since they are not rooted in and the moisture gets wicked out. If I planted this late I'd remove blooms so they could put all energy into roots but even so if its hot growing slows down in summer as plants just try to survive, its not only a bad time to plant, its often a bad time to prune.

Thank you, everyone.

OK, so I'm getting the sense that though there are many perennials that if planted in the spring will bloom late summer and early fall, my thought that I can plant those varieties now and expect them to bloom fully then is an iffy proposition. It may work and it may not. In order to have this late-season blooming, the plants need to have well-established root systems, and planting in early August may not give the plant enough time to establish those roots, is that right?

Yet presumably nurseries are full of plants for planting now.

Perhaps the staff don't explain the challenges of doing an August planting. Or they expect the customer to know that they're planting for next year's bloom.

So If one is planting for next year, is it better to wait until the spring to do that, rather than planting now?

NHBabs, Sunnyborders, MizGG: if I can find some of the varieties you mention, in your opinion can they be planted now and be expected to bloom late?

Or am I better off going mostly with annuals to fill out the rest of the season, and start with perennials in the spring?

Hi, Rick, yes, in my experience, some perennials will bloom--with proper care--this time of year. In my area, many nurseries have late season sales, and I plant often in July/Aug ... in very harsh conditions of brutal Texas sun, 100+ temps, no rain. I baby them somewhat, and they're happy.

I just planted a Flame Acanthus, gaura, and lantana a couple of weeks ago, and they haven't stopped blooming. (I believe your area is too cold for them, so I'm not recommending those for you, just using an example.) Certain varieties of salvias have always bloomed for me, newly planted.

So you're right, it's iffy, and since you're wanting color now, I'd do both--annuals and perennials. You'll be covered either way for this year, and have a good start for next year. :)

You're in zone 6b - heck ya, I'd plant any fall blooming plants that you find now. Anemone Honorine Jobert is the PPA plant of the year )and a very nice choice) so you should be able to find her at big box stores for cheap.

Thanks, everyone.

Let's say I decided I mostly wanted to plant for next year. Would now be a good time to start, or is it better to wait until spring (or September?) for that?

Sorry -- I didn't mention: I'm just outside of Boston.

Rick7072 - I'm 3 miles south of the MA state line in Central CT so pretty close to where you are. I'm guessing you've had a similar drought to the one that has impacted my garden this year. My garden beds are mature; I started designing them in 2006 and all were planted when I was "finished" in 2008. The plants have had several years to get established but this year's drought has definitely affected even my mature plants. Many show signs of stress due to the lack of rain despite having healthy & mature root systems. The only things I planted this year were annuals in containers that I could water daily. I have a well so normally don't water the garden beds. They're too numerous and distant from the hose.

Anything you plant now is starting with a water deficit so that jeopardizes its chances of survival especially if the drought continues the next several months. The plants won't go dormant in the best condition which will reduce their chances of survival through a harsh winter.

I don't mean to sound like the grim reaper but just to offer concerns that may help you avoid disappointment. I love my garden beds and am glad I planted them the way I did when I did so they'd be mature for me to enjoy them for many years. Wishing you a like experience.

I just cannot see the benefit of keeping a mature plant in a pot until autumn weather...the pots are even more vulnerable to heat and drought than being in the ground. There are (as always) a couple of caveats to this though - if you can keep your pots under shade, out of wind until a more clement planting time...or if you are dealing with young seedlings, then waiting till autumn will generally be better - cooler, damper soil will put less stress on the plants and will enable them to establish and still put on more rootmass...but for the sort of plants we see in nurseries, already mature enough to bloom, there is not much point in waiting - those plastic nursery pots offer very little protection for extremes of heat and will not allow for root expansion either. Plenty of watering will be necessary whether in pots or ground.

I have no access to water in the woods...so autumn is my only window for safe planting...I do the years worth of planting in a 6 week period- including bare-roots/hedges, bulbs, seedlings and mature plants.

I do most of my planting in September, and I think in Boston you could easily extend that into October. I'd for sure plant annuals for this year, if for no other reason than because the perennials and shrubs you would plant need room to grow, so annuals between them makes sense while they gain size. Be sure to check the ultimate size of plants (especially the hydrangeas) and give them enough space.

If you will be willing and able to pay attention to watering needs (actually check the moisture level in the soil with your finger 3" or so down and water as needed), go ahead and plant now. Just be aware that things may look kind of bad for this year since the plants will most likely have some shock planted now. If you do plant now, be sure both the bed and the root balls are well-moistened before you plant, and give the new plantings some shade temporarily (a week or so). (I often use lawn chairs placed to provide shade in the hottest part of the day.)

I think it depends some on your actual site conditions, how large an area you are considering planting, and if you are on town water. If your town has watering restrictions and it's more than a small bed, I'd wait until we've had sufficient rain that there aren't watering restrictions.

Sunnyborders, thanks for the note about the Dundee guide to deadheading which I found here: http://dundeenursery.com/FactSheets/deadhead_perennials.html.  Good to have this.

Anyone care to venture some thoughts about the pros and cons of planting perennials for next year this September vs. next spring? NHBabs, you mention that you do most of your planting in September and I'd be curious to know why you choose then rather than the spring.

Here in Oklahoma we have approximately the same first frost and last frost dates as you do. However, we have hotter/drier summers, tomorrow is forecast to be 101. Planting in summer here would be fool hardy and a time consuming daily chore to keep them watered and shaded in the afternoons with the exception of warm season grass plugs in 4" pots. Those do fine planted in summer, in fact I just planted several more for the third time this summer. They seem to thrive on heat and do fine with just weekly watering for only a couple weeks, after that they are settled in and I can stop watering.

Fall is the best time to plant for us, usually around the first of September when the sun is less intense and temperatures start cooling down from the upper 90's into the low 80's. Most importantly the ground is warm unlike it is in spring so you get better & faster root growth with good weather until the first of November (sometimes longer) and the soil is reasonably moist all winter (usually). Come spring, the plants are fairly well rooted and good to go giving a big head start over spring planted ones, they also fare better with the sometimes early onset of hot temperatures and occasional dry springs.

The only exceptions I make is for plants that stretch the limits of cold hardiness. We are zone 7 but I grow several zone 8 plants. I'd plant those only in spring as early as possible.

Another huge fan of autumn planting...in fact, until recently, nearly all plants were actually field grown and dug up bare-rooted to be bought and planted only in autumn. In the UK, the soil remains warm for weeks and weeks - planting potted seedlings and perennials can be done through to November while bare-root trees and shrubs can be done all through winter as long as the ground is not frozen. There is evidence to show that most rootgrowth occurs from the end of summer into autumn and if this occurs while the temperatures are not stressing plants with excess heat and lack of irrigation, autumn is absolutely the best time for most of us...and as I always do a large bulb planting, I like to get all the planting - bare-roots, divisions, transplants, seedlings done at once. The only caveat to this is when division happens in spring (as with late bloomers such as asters).

Rick, I plant in the fall because the soil is warm and the air temperatures are cooling and days shorter, so the plants aren't as stressed. NH has rather short springs and the soil is cool while the days are sometimes quite warm, so the plant is more stressed by the heat and long days. Like Camps, I have also read that most root growth takes place in the fall. I do mulch after planting to keep the soil warm as long as possible and to prevent any possible frost heaving in the spring, and keep close watch on soil moisture levels so they go into winter with enough hydration, though not soggy. I find with fall planting, there's little transplant shock and the plants grow well the following year. I do this with everything except annuals, even evergreens, which the conventional wisdom says not to plant in fall in areas where the ground freezes.

Rick7072 - in response to your question re: planting in fall vs. spring: perennials "know" to begin their dormancy when temperature & daylight hours trigger their genetic code to do so. Planted in September, perennials will switch from "grow NOW!" mode to "slow down & go dormant soon" mode. In automotive terms, they stop revving their growing/blooming engine for the race to the finish line and switch to their "idle" gear.

A lot of this depends on the cycle your local nurseries have. Around here, they typically get in a lot of small, cheap plants in the spring, larger, more expensive plants in early summer, then very little new stock until September. Some places spend fall trying to unload stock since they don't do much in the way of overwintering. If the plants are available, they can grow roots over the winter. If they aren't, or your budget prefers smaller, cheaper ones, waiting until spring can be better.

Thanks, gardenweed. If plants enter "slow down and go dormant soon" mode, why would that be what we want? Isn't the purpose of fall planting to give the plant a chance to grow some roots and establish itself before the winter sets in? A couple of folks here have noted that a great deal of root growth occurs from the end of summer into autumn, and I thought that's what we would want for September and October, rather than slowing down.

I ask this out of not knowing enough one way or another-- this is all educational for me!

Thanks, mad_gallica. I wasn't aware of this purchasing cycle of nurseries. So often they will not get many new plants between early summer and September? And the September plants that they get in -- I'm presuming these are annuals intended for blooming over the next month or two until a frost, as well as perennials to plant now for blooming next year?

rick77072 - Plants know what to do and when and have their own schedules pretty much the same as humans. Yes, fall is slow-down-and-go-dormant time for perennials where we garden but that doesn't mean they won't establish root systems simultaneously. They just do it when their top growth isn't screaming for and demanding moisture to produce blooms. It's sort of relax, it's not as hot now so just do what you know to do without the demands for producing blooms. Here in southern New England, fall is milder temperatures + fewer hours of daylight so the plants have a chance to let their roots get a good grip on the soil that will sustain them the following year when they're expected to send up new growth, produce flower stems & blooms, store nutrients for the coming cold season, etc.

I'm no expert; I'm just a gardener who did her homework before designing and planting perennials. Judging by what I see each year when my garden beds wake up, it seems apparent I did things right. So far the only things I've ever lost were short-lived perennials and my only regret is I didn't KNOW they were short-lived when I planted them.

I did do a shade study before I even stuck a shovel into the soil or scratched a rough design for a garden bed so I'd know where there was full/part sun or full/part shade in my garden. I knew I had healthy, slightly acidic sandy loam because my parents practiced organic gardening for 40 years before I moved here. I just tucked that knowledge under my belt and started planting.

I have lots of photos, just don't know how to post them since GW switched over to Houzz.

BTW - GardenWeb folks were informational for me as well when I first stumbled across this form about 11 years ago. There's a lot to be learned.

The purchasing decisions are very regional. Nurseries in your area may get in a good selection of hardy perennials in the fall, but the selection is much better in the spring. So if you go shopping and are underwhelmed by the choices, spend the winter planning then do your major shopping in the spring.

Can folks confirm what I think I've gathered from reading posts here: for planting perennials it would be better to wait until late August or early September to plant instead of now? And this is because newly-planted perennials will struggle both with the heat and drought-induced dry soil that we have now?