Tag Archives: dahlias

Fall Is the Best Time To Plant

digging spade

“Fall is the best time to plant”  That’s what I tell my students (and anyone who asks). The shorter days and cooler temperatures make it easier for transplants to spread their roots without us hovering nearby with the sprinkler. Usually there’s some rain too, though not this fall, not much. But the dry weather is not nearly the problem it would be in the spring and so we are madly digging and dividing perennials all over the garden.

Why divide? After a few years — as few as 3 or as many as 10 — perennial plants begin to lose vigor. Often they grow toward the outside, leaving an empty space in the middle like a bird’s nest. They may flower less, have smaller leaves, or flop over more. They may also have gotten too big for their space in the garden. Dividing re-invigorates the plants, and as Tracy Aust says, “It can be very satisfying, having a rejuvenating effect on perennial and gardener alike.”

Of course, after digging and dividing and transplanting, you may have more plants than you can use.  I overwinter many garden-dug perennials for our spring plant sale, but space is at a premium this year. A truckload of perennials has been donated to two local schools, saving me from having to compost them. Thanks Jayne and Hilary, for gardening with the kids!

One last thought about digging and dividing: the plants may not look great at first but in the spring they’ll look better than ever.

hosta bed The Hosta bed under the Metasequoia was dug up and replanted.

pink chrysanthemumsOver near the Co-operative Extension parking lot we  put in new plants to go with these great Chrysanthemums that look like pink daisies.

bee balm/monardaLauren and I dug, divided, and replanted Bee Balm in the ericacious garden and the sunny border. We also took some Siberian Iris out of a bed that was too shady and put in Ligularia, which I think will do well in this moist, shady spot.

digging Joe-PyeAdam and Ben got started digging up the monster Joe-Pyes in the back of the sunny border. Topping out at 10-12 feet this year, their root balls are two feet across. They are going to be moved back so the rest of the plants can breathe.

dahliasStill no frost here, so flowers continue to bloom, especially dahlias, which seem to get bigger and more colorful every day.


Getting Back to My Chores

perennials in flats

After Hurricane Sandy, Election Day, Northeast Greenhouse Conference, a nor’easter, and Veterans Day, it’s time to get back to gardening. Right before the storm, Dr. Maynard’s PLS 350 class came out and helped me dig up most of the plants in the sunny border. The plants have been sitting outside in my “cold frame/nursery” area behind the greenhouses. They are semi-bare root, since they are in flats covered with fallen leaves, but not potted up. When the weather is cool they can sit that way for a long time. Fortunately they won’t need to, because tomorrow we plan to replant the border, again with help from the class. Divisions of the plants which were dug up will go back in with room to spread their roots. A few thing which did not do well there are not invited back! And maybe a few new plants just to change it up.

garden bed

Our other chore for the day will be lifting the dahlia tubers. The dahlias were cut back after the first hard frost (“Changing Seasons“) but left in the ground. Waiting until the last minute to dig them up reduces the amount of time they will be in storage, where there is the possibility of decay in the tubers. Where to store them? Not too warm, not too cold, not too wet, not too dry! Maybe under my basement bulkhead stairs, or maybe Dr. Maynard’s root cellar.

dahlias waiting to be dug

The weather for tomorrow looks to be sunny and cool, perfect for working in the garden. I love being outside at this time of year. With the right layers (as our friend Russ says, “It’s all in the gear”), and maybe a hat, I’m outside all day, enjoying deep breaths of cool refreshing air that’s like a long drink of water. Bright sunshine lifts my spirits, and a daydream about how good it will look in the spring keeps me going.

Enkianthus fall colorJust for Fun: This Enkianthus is one of the last plants in the Botanical Garden still displaying beautiful fall foliage. My favorite plant blog, “Botany Photo of the Day”, featured an Enkianthus recently — “Enkianthus campanulatus“.

Changing Seasons

Jack Frost visited Kingston Hill in the still hours of Saturday morning (October 13th, right around “average” first frost). It was just cold enough to end the display of dahlias, and kill off the marigolds and peppers left in the All- America Selections garden. The tropical garden up between the greenhouses is still alive and well, being in a very protected spot. But come and see it soon, because it won’t last much longer! The tropicals will need to be dug up and brought inside for the winter. Chore of the day is to continue the cutting back and cleaning up we began last week.

frost on monarda

Photo courtesy C.Cramer

Being a gardener means always having an eye on the weather. I’ve been intrigued this week with two documents shared by Carl Sawyer of the URI Agronomy Farm and Weather Station. (Kingston has been reporting temperatures to the National Weather Service since 1888 or so!) One is the first and last frost dates and number of frost free days in Kingston from 1931 to 2011. The highest number of frost free days on the list occurred in 1955 at 188 days. The lowest was in 1991 at 116 days due to a very late last frost — May  29th. A bad day for growers, as a late frost is so much more damaging than an early one.

The other is a 1948 Ag Experiment Station bulletin showing the average growing season for different parts of the state. Kingston is clearly a cold spot, showing at that time a 136 day average growing season.  East Farm, also in Kingston but at the top of the hill, shows a 167 average day growing season. The “micro climate” makes a big difference. (Update: temperature Saturday morning was 25 F “down” at Agronomy and 29 F “up” at the greenhouse.)

On our weekend trip to upstate New York to visit our college freshman, glorious autumn leaves were everywhere, about a week ahead of us here on the coast. The weather forecast is for a mostly sunny and mild week, a great time to get out and enjoy the changing seasons.

autumn leaves and berries

The Colors of Autumn

Under sunny skies or gray, colors of the garden seem at their fullest right now.

bi color dahliaMany thanks to Donna Lane and the Rhode Island Dahlia Society for their generous contribution of Dahlia tubers to the Botanical Gardens! After losing many tubers to decay in storage last year, I contacted them and they were kind enough to offer us a great selection. No, I still don’t know the variety names, but any reader who does is invited to let me know!

large red dahlia

tropical garden

red seed pod closeup

The tropical garden at the back of the All- America Selections Display Garden between the greenhouses became as colorful and lush as I had dreamed of. The large green leaves right in the middle are a cold-hardy banana plant, which will stay outside all winter (with some protective mulch and wrapping), and hopefully delight us in the spring by being alive and well.

goldenrod and physostegia

Goldenrod (Solidago spp.) and Physostegia are a great combination for fall. Goldenrod is underused as a perennial garden plant. I think it is unfairly associated with hay fever. The real villain is usually ragweed, which doesn’t have conspicuous flowers and thus evades suspicion!

cajun belle peppers

‘Cajun Belle’ and ‘Cayenetta’ are two peppers growing in the AAS Garden. Medium hot and very productive, they add to the Colors of Autumn at the Botanical Gardens.

Back to the Garden!

empty greenhouseNow that the plant sale is over (and a great success), it’s time to return my attention to the Botanical Gardens. The plant sale is a lot of work, although it’s a lot of fun too, and it’s gratifying to see the greenhouse EMPTY! Many thanks to the students who helped me out the past two weekends.

I am really happy to be back outside in the Garden, even to pull weeds. The main garden, where the stage is, looks good. This part of the Garden is the area most often reserved for special events. The College of Nursing will be holding their Commencement ceremony here.  A retirement party for the Dean of Pharmacy, Joan Lausier (celebrating 50 years at URI!), will be held in the Garden in June. A few weddings are already scheduled, and of course garden tours are always going on.

peonyMay is a busy time for garden chores. There are peonies to stake, already flopping with last night’s heavy rain. Annuals are ready to be tucked into the perennial beds for extra color. Plants for the All-America Selections Display Gardens are getting impatient in the greenhouse and will be planted out this week ( hopefully!) Dahlias need to planted, Montauk Daisies cut back, and of course, the never ending task of weeding.

all-america  selections logoSpeaking of chores, our summer garden crew is all new. Welcome, Louis and Feather. And good bye to Mike (Bartlett Tree Service), Giles (Central Nurseries), and Emily (Tower Hill Botanic Garden). You will be missed! Ryan (Arnold Arboretum) and Kyle (adventure), hope to see you in the fall. Let Summer Begin!

lavender and roses in June

October Garden

white anemone flower

What’s left in the October garden? The weather has been so mild that many plants are still lingering in the slanted autumn light. Japanese Anemones look beautiful in the main garden. The white ones, ‘Honorine Jobert’ stand up proudly and make themselves seen. The pink ones, ‘Queen Charlotte’,  lie down as soon as they bloom, tangling themselves among the skeletons of the Sedums and Rudbeckias, tempting me to rip them out despite the beautiful pearly pink color and abundant flowers. Speaking of Sedums, they seemed to go by quickly in the wet grey week we had, along with my favorite aster, the bright ‘Alma Potschke’ in the main garden. The Actaea along the Kinney wall is still standing, the seed pods as eye-catching as the fuzzy white flowers.

actaea near stone wall

Annuals are still alive and well here on Kingston Hill, although the temperature really dropped the first week of October. Teri of Hidden Field Farm in Wakefield reported a killing frost the night of October 6, but we’ve been lucky. Or maybe not lucky — it feels a little like limbo. Do I pull out the tomatoes in the All-America Selections garden, which are still flowering and fruiting but look ugly and half dead? (I did.) What about the ‘Holy Mole’ peppers, and the Celosia ‘Fresh Look Gold’ ? (I left both –the peppers look healthy and productive, and the Celosia looks….interesting.) A hard frost is definitive, leaving no questions about what should be done.


Other bright spots of color: the Calendula near the front of the Kathy Mallon Outreach Center, the Dahlias of course, the Callicarpa with stunning bright purple berries near the fire lane. The Nepeta in the main garden, an occasional Rudbeckia. And the Rose Garden is full of pink, red, white, and yellow roses…  A wedding there on October 9th caught a beautiful perfect blue sky day among the late roses.


 The weather forecast is not for cold but for rain, which might spare the annuals but be the end of the perennial flowers. Of course it’s inevitable that they will all be gone soon, but what a gorgeous “Indian Summer” it’s been.

sedum autumn joy

Beautiful Strangers

large orange dahlia

The Dahlias are at their peak and I still don’t have my camera back!  I can try to describe them but really, a picture is worth everything here….Giant clear raspberry pink, pastel orange — 10 inches across! A huge deep red, a pink waterlily type with an orangey blush, a yellow cactus-flowered…And they grew! On September 6th I wrote that none of them were over 30 inches tall. I guess I have to take that back because some of the plants are now towering over my (5 ft) head. One of the reasons I love Dahlias is because they are so vibrant at a time of year when a lot of the garden is ending it’s display.   If you walk by the west end of the greenhouse building, take a minute to enjoy them.

shadow on light pink dahlia

The other part of the Dahlia saga this year is that I don’t know the cultivar names, since the tubers were unlabeled (tho that’s part of the fun!) Searching the internet in an attempt to figure them out,  I did find some beautiful pictures, but it’s still hard to say who ‘s  who.  I’m including a few pictures here and if anyone knows the names of these beautiful strangers, I’d love to hear from you.

large dark red dahlia

Late Summer Royalty

white dahlia

In the spring I referred to peonies as the “Queen of Flowers”.  Perhaps I should have said the Queen of “Early Summer Flowers”.  Because now as summer begins to wane, (it’s not over yet!) there is another queen: the Dahlia.

Dahlias are strikingly beautiful flowers which come in a huge variety—thousands of cultivars— of colors and sizes. They are native to Mexico but have been known and loved in Europe since the early 1800s.  Garden dahlia flowers range in size from 2-3 inches across to as large as 12 inches across. The plants themselves can be from just 12 inches high,  great for low borders or even containers, to as tall as 48 inches.  Colors range from white to pink, yellow, red, purple and everything in between.  (But not blue, green, or black, as far as I know). The flowers come in many forms : “cactus”, “pompom”, “anemone”, “single”, and more. This link has nice clear pictures of the different flower forms:



I received a gift last fall for the Botanical Gardens from Linda J. — a big muddy pile of unlabeled dahlia tubers. After rinsing and letting them dry, I wrapped them in newspaper, packed them into a waxed box, put the box in the cellar, and forgot all about them.  In the spring during a cellar clean- up day, one of The Boys found the box and brought it up. It was a little late — the tubers were sprouting, a few had shriveled up, but nothing was rotten.  I decided to plant everything that looked even remotely viable. We staked them all, not knowing if they were dwarf or tall, large- or small-flowered. (Staking  can be critical: Large dahlia flowers are heavy, and the stems are hollow and brittle.)


So,  it’s September, and here they come!  We have a large (6-7 inch) pink and 2 large white,  a medium sized pink, and lots of buds.  I’m hoping for all kinds of colors! None of the Dahlias are over 36 inches or so, which means that next year they go in a more visible spot.  Right now they’re in the garden just west of the greenhouse, tucked between the hedge and the ‘Heatwave’ Agastache.


Dahlias can be grown as annuals, but I treat them as tender perennials. When a hard frost kills back all the foliage,  the tubers will be dug up,  LABELED, and packed away for next year. In the spring they can be divided and each section of tuber with an “eye” will produce a new plant.  In a good year there will be 3-5 new tubers on each plant — plenty to share!


Like the other Queen of Flowers, the Peony, Dahlias are not  hard to grow. They prefer full sun and  well drained soil. I planted them like potatoes, putting the tubers in the bottom of the hole, covering with only an inch or two of soil,  and gradually backfilling the hole as the stem grew until it was filled in. A low nitrogen (vegetable garden ) fertilizer and a little bonemeal is enough. They don’t need heavy watering and tolerate heat and dry weather, although watering once a week when they begin blooming is helpful. Dahlias make great cut flowers as well as being a bright spot in the garden through September.  Here’s hoping we have a whole rainbow of colors to enjoy this month.