Pruning Shrubs – Should they be pruned after flowering?

Robert Pavlis, Guelph

The standard advice is to prune spring flowering shrubs right after flowering and to prune summer flowering shrubs in winter or early spring. Pruning spring flowering shrubs after flowering ensures that the shrub has time to develop next year’s flower buds. Summer flowering shrubs develop flower buds in spring on new wood so they are pruned before flower buds are formed.

This is not bad advice for maximizing flower production, but is it the best advice for the vigour of the shrub?

The shrub responds to pruning differently depending on when it is done. Pruning during dormancy (i.e. late fall to early spring) removes dormant leaf buds and may also remove dormant flower buds. Pruning during dormancy does not cause the shrub to initiate new growth. Pruning in mid or late spring after flowering has a different effect. Pruning removes newly formed leaves in addition to wood. The shrub has just grown the leaves and in many cases they are not yet fully developed. The process of growing these leaves requires significant food reserves – food that was stored the previous year. The leaves have not yet paid the shrub back for using these food reserves.

The shrub’s reaction to losing leaves is to activate more dormant buds and many shrubs tend to over react by activating more buds than they really need. This drains even more of the food reserve. Pruning in mid to late spring weakens the shrub by depleting extra food reserves. Most shrubs will survive this situation, but it is not really the best thing for the shrub.

The advice to prune spring flowering shrubs after flowering is good for flower production, but it is not the best advice for the health of the shrub. 

Pollarding: Is it Sensible Management for Street Trees or Just Plain Tree Abuse?

Lucerne, Switzerland

Gary Westlake, Peterborough

I have always thought that topping a tree was a bad thing to do but this might be just my North American bias. Where we grow most trees, we have the luxury of space to allow them to do their own thing, but this is not always the case in Europe and elsewhere.

Carrying on the centuries old practice of pollarding has permitted trees to be used in urban locations where they would quickly outgrow the available space if left to their own devices. Pollarding was originally used to provide the fast-growing whips used for baskets, wattles and forage for livestock. It was also brought into city streets to control the size of street trees.

Pollarding is the straight forward but scary and expensive practice of allowing a young tree to reach the height you would like to keep it at, then cutting off all its main branches including the leader and then yearly pruning it to maintain this height for the life of the tree. There is a great deal of skill and experience required to keep the tree from becoming weak or diseased. Pruning is normally done in spring before the leaves come out, causing the tree to respond by sprouting vigorously from dormant buds. Each year the whips are removed so that the tree forms a gnarly knuckle of scar tissue. Unfortunately, if you stop maintaining these trees for a few years, they can become very weak and dangerous at the knuckles. Many trees will not respond well to pollarding but some that work include oak, catalpa, maple, linden, mulberry, redbud, willow, hornbeam, and black locust.

These trees, while they look very little like the species growing in nature, have a certain architectural quality to them and they provide shade and a bit of greenery to places where it would otherwise be impossible. If you have ever walked along the lake in Lucerne, you would find it hard to judge the practice as barbaric.

Contrast that with the common practice in our cities of planting trees in “tree coffins” and replacing them when they get too big or die a slow death; or our practice  of planting a large tree under power lines, then abusing it later as it tries to grow. I would not want to see a pollarded tree in our garden but perhaps it should be kept as an option for urban environments.

Pruning for Table Grapes

Mary Beerman, Durham Master Gardeners

Pruning for grapes has a number of adaptations depending first on the grape selection, and second on the type of training the vine has undergone.

There are 3 basic types of grapes that can be grown: Vitis vinifera, European wine grapes and the ‘Thompson’ seedless, Vitis labrusca, which includes the hardier American hybrid grapes and Vitis rotundifolia, which includes the Muscadine grapes best suited for southern gardens. Carefully select a cultivar appropriate for your climate as well as for your training and pruning preference. Some cultivars are best suited to specific training and pruning.

Pruning grapes begins at planting; for most of us this can be in early spring or fall. It is best to first have your trellising, pergola or staking in place, however, temporary staking can be done for the first growing season. You will need to replace this staking with a permanent structure during dormancy in the first year (late fall-winter). In year 1 you prune to establish the trunk of the vine. At planting, cut your vine back to 2 -4 buds. Remove all other vegetative growth. In early spring of year 2 prune your vine back to 3 – 4 upward facing buds. When these have grown to approximately 8” long choose the healthiest shoot to serve as the trunk; pruning off all other shoots except for this one. This shoot is your ‘insurance’ shoot. It will serve as the ‘renewal spur’. Prune this shoot back to 1 or 2 buds. As the vine grows continue to remove any new side shoots appearing along the trunk. You can let leaves remain as important feeders to the trunk. Once the trunk cane grows just higher than the first, or preferred, trellis wire or the top of the pergola prune the cane tip and tie it to the support. This pruning action prevents the cane from growing taller and provides a point for attaching the vine. The pruning that follows will depend on the type of branching framework (training) preferred by the cultivar, the type of trellis structure you have chosen, your garden space and your climate.   

There are several ways to train your vine. The two general types of training: Cordon-Trained vines and Head-Pruned vines. Since pictures paint a thousand words review the diagrams below for an orientation to each type of training.

 For cordon-trained vines, after initial pruning, train two permanent lateral arms, or cordons, to grow along the wire in opposite directions.

For head-trained vines, prune the trunk to the top trellis wire. Choose five lateral shoots to grow from the head of the trunk, then train the arms along the wire.

Grapes fruit on one year canes. Annual and bi-annual pruning is required to maintain a productive vine. When you prune depends on how cold your winters are. In Ontario it is best to prune in early spring when the coldest of weather has passed. This timing will allow pruning wounds to heal and you will have the chance to remove any winter-kill. There are a few rules to follow for effective pruning:

• Prune any shoots growing on wood older than 2 years.
• Prune canes that are not fruit bearing.
• Hand pull leaves around fruit clusters nearing harvest to allow for full sun exposure.
• Prune canes that overwhelm the trellis.
• Early-prune fruit cluster tips to force larger fruit and denser clusters.
• Pruning can remove up to 90-95% of the vine growth each year.

There are two basic methods of pruning: Spur pruning and Cane pruning.  Note the diagrams below for direction.

For spur pruning vines, start with a cordon-pruned vine. Choose 6 to 8 spurs. Each year, remove the previous year’s growth and the cane furthest out on each spur, then cut back the remaining fruiting cane on each spur to 2 buds each.

For cane pruned vines, prune canes back to 8 -15 buds for fruiting every year and leave 2 bud spurs for next year’s harvest. 

Everything Under One Cover

Edythe Falconer, Ottawa-Carleton

The Ultimate Practical Guide to Pruning and Training – Richard Bird – Hermes House - 2005

The author has put together the most comprehensive reference on pruning that I’ve ever encountered in many years of gardening. I acquired this publication by accident. I was in a Lee Valley store this spring looking for a book on Grasses. Bird’s book was on special at an irresistible price so I came home with two great books instead of one. I will soon donate most if not all of my “old” pruning books to our swap table and/or our spring plant sale in 2014.

In a mere 256 pages Bird covers ornamental trees, ornamental shrubs, topiary, hedges, ornamental climbers and wall shrubs, roses, perennials and annuals, fruit trees, climbing fruits and soft fruits. Added features include a directory of ornamental plants and an extensive glossary. There is something here for both the generalist and the specialist. Especially helpful is the wealth of informative colour photos and diagrams. There are many other pluses. Bird serves his reader well with suggestions for support structures for plants and their relevance to styles of pruning. He provides diagrams for building some of his favoured structures. He comments frequently on levels of difficulty in maintaining specific plants. He includes the Latin names of many of the plants he uses to illustrate his techniques and he even goes so far as to suggest many creative yet sensible, doable design ideas. All of this is delivered in a pleasant friendly style that makes for comfortable learning and reading.

I found this book by accident. I’m recommending that you consider getting it by intent. Although I now do a lot of my research on line I still value greatly references of this calibre! Do check it out.

Visiting Gardens While Traveling

Dianne and Gary Westlake, Peterborough

(Published Previously in the Peterborough Examiner in the summer of 2008, so the date references  are a bit off.)

Buchart Gardens

We love to visit gardens while we are traveling. This year we went to Seattle, Vancouver and Victoria in the spring. We traveled to Wales, Scotland and England in the fall and this summer we visited Quebec. At each of these places we found great gardens to visit and this is the time for you to start planning a trip for next year.

In the spring of 2007, we went to Amsterdam to see tulips. We also saw the auction house where they sell and export millions of flowers. Unfortunately, the weather was unusually warm, and although the display gardens at the Keukenhoff were wonderful, the fields where they grow tulips for the bulb market were nearly finished. Fortunately, this year we found similar fields of tulips in the state of Washington that were at their peak.

We spent a whole day at the botanical garden on the campus at the University of British Columbia in Vancouver. The garden had an enormous collection of plants from all over the world. It is well organized and labeled. It had a great vegetable garden with espaliered fruit trees in amazing configurations. There was even a pear tree trained on a wire a foot off the ground. It was a great place for a walk and was not very crowded. Places like this are under a lot of pressure from building development, in this case from the University. If gardeners do not visit, they may succumb to development, so go have a look at this great garden while it is still there.

In Victoria we saw Butchart which is like Disneyland for gardeners especially in the spring. There were seas of spring flowers and a views from the top of an old quarry filled with gardens that cannot be missed. Every time we turned a corner in the garden there was another beautiful view.

This summer, we had an opportunity to visit Les Quatre Vents in Quebec. You have to plan well ahead for this one by booking on the website. Now would be a good time to do this. It is only open to visitors a few days in the summer but it is well worth the day-long drive to get there. Situated in La Mal Baie a couple of hours drive past Quebec City on the north shore of the St. Lawrence River, this garden needs most of a day to see properly. The drive along the north shore through the Charlevoix area is beautiful.

This would be a great trip for gardeners going to the east coast of Canada, to stop at the Montreal Botanical Garden, spend a day or two in Quebec City seeing the old area of the city, then on to Les Quatre Vents and across the river by ferry to Reford Gardens on the Gaspe. Then you could either take the long route around the coast or cut across through the picturesque Matapedia area on highway 135 to New Brunswick. On the way back in St. Jacques, New Brunswick, there is a great garden just before the New Brunswick-Quebec border called le Jardin Botanique de Nouveaux Brunswick.

On our trip to the UK this fall we had a number of surprises. Some gardens like Tatton Park that we were looking forward to seeing, were not as impressive as we thought they might be. Some we chose to visit at the last minute turned out to be wonderful. We had a great time in the Alnwick Garden in Northumberland and the Biddulph Grange Garden in Staffordshire and neither were on our list of gardens to visit. There are also gardens open for charity in England with hundreds of private and commercial properties. You can find the information by purchasing the guide called the Yellow Book at the National Garden Scheme website www.ngs.org.uk for £12.99.

Now that we have seen Hyde Hall and Harlow Carr, we have visited all of the Royal Horticultural Society's official gardens. These gardens are all grand places. Even though we live in Canada, we are members which gives us free entry to these gardens as well as discounts at others. The monthly magazine alone is worth the cost of membership. The Botanic Garden of Wales in southern Wales is wonderful as are the Botanic Gardens in Glasgow and Edinborough. Although we were late in the season, there was lots to admire. If the weather is nasty, they offer glasshouses full of plants from other climates. The Bodnant Garden in northern Wales was one of our favourites. When we were in Wales, there had been a lot of flooding and the stream going through the garden was a raging torrent, but the garden was amazing and spectacular even in the rain.
Because the weather was bad in northern Scotland we decided to go to Bressingham, north east of London and were pleasantly surprised. It looks like a regular garden centre from the road with a train amusement park attached, but the display gardens are great. The gardens have a huge number of perennial borders and island beds to get ideas from. Whether it be close at home or far away, we hope you will start planning a trip for next year now and that you will include gardens in your itinerary.


We are not getting any younger, and putting these trips off is not an option. We are already starting to feel our joints creak as we go up and down the stairs. Please let us know if you find any gardens we should see. Here you can see a few photos from our trips.

Great Gardens of England

Joy Cullen, Nothumberland

White Garden, Syssinghurst

In July 2013, two Northumberland Master Gardeners and two friends embarked on our first Road Scholar trip “Great Gardens of England and Hampton Court Flower Show”.  This was a well-organized excursion with a small group of compatible travellers which included all meals, entry fees and had an education component.  A retired professor of horticulture and garden history provided five lectures.  Gardens visited included:  Great Dixter, Goodnestone Park Garden, Sissinghurst Castle Gardens, RHS Wisely, Hidcote Manor, Kiftsgate Court, Painswick Rococo Garden, Stourhead, Blenheim Palace and Hamptom Court Flower Show.

I am generally not a fan of roses but would be if I could grow roses like I saw in England, shrubs, climbers, teas.

Haha Used to Control Livestock

Christopher Lloyd at Great Dixter loved to experiment – I found the very formal topiary under-planted with a wild flower meadow. Had never seen a haha before – much nicer than a fence.

We enjoyed the golden arboretum at Goodnestone Park, planted to celebrate a 50th anniversary. The White Garden and the Rose Garden at Sissinghurst were spectacular. The panoramic view from Hidcote in the Cotswolds was stunning.

Painswick Rococo garden is the only complete survivor of an 18th century pleasure garden. It is a very theatrical garden style – a place for the squire to have fun.

Stourhead had the most amazing collection of trees.

Blenheim Palace, the birthplace of Winston Churchill has a Capability  Brown Landscape Garden.
Hampton Court defies description.  It was huge and crowded. The grower’s demonstration gardens showcased large numbers of just about every flowering plant you could imagine.

To sum up, for me English gardens are large old trees, amazing roses and interesting hedges.

A Gardener’s Staycation

Edythe Falconer, Ottawa-Carelton

Les Jardins d’Emmarocalles

My Staycation included a group trip to Les Jardins d’Emmarocalles near Ripon, Quebec – about an hour’s drive from downtown Ottawa.  Although the five-acre garden is only six years old it has already expanded to include more than 1500 daylily cultivars and a thousand varieties of perennials.  Divided into twelve different sections or sub-gardens it is aesthetically pleasing and educational with each garden representing a different style and different growing conditions.

Les Jardins is part of a network that exemplifies local self-sufficiency, community building and agri-tourism.  On their own site they cater luncheons that feature locally grown products – fruit, vegetables, cheeses and meats.  They also sell some of the plants they grow.  Within easy reach of each other are sources of goat and sheep-milk cheeses, free range beef and poultry, berries and fruits, maple syrup and locally produced arts and crafts. No 3000 mile products here!
Agri-tourism – Tourism Outaouais – Day trip www.outaouaisgourmetway.com

Diana Beresford-Kroeger

Beresford-Kroeger is many things – author, renegade scientist, botanist, medical biochemist, speaker, and a major force in movements to reforest the planet. Her primary focus is to collect and preserve rare and endangered species and to that end she travels the world.  In fact, she and her husband were in Russia at the time of our group tour to her large and fairly secluded property.  One of her associates acted as our guide.  It was certainly an interesting and unusual experience.

There is nothing here that feels like being in a conventional garden with the possible exception of the vegetable plot. Everything else looks wild and unplanned.  However contained within this wildness is a considerable collection of rare and endangered species along with many of our old stalwarts.  Here is a fine example of permaculture whereby everything has more than one use, garden needs are supported in more than one way, biodiversity is celebrated and cultivated, native species are more than welcome and biological resources are not hauled off to the nearest dump. Rambling trails wend their way through Diana’s laboratory, knowledge is shared and discussed and an illuminating afternoon was enjoyed by all.

 

XXXX - My Renewed Romance with Annuals

The welcome “mat” at the front of the house cost a bit up front – literally – but has been worth it in so many ways. Because the harsh looking, heat-radiating tarmac was anything but welcoming and was surplus to our parking needs, I contracted to have five planters installed late last fall. This spring I filled them with mostly annuals and the result has been utter joy.  Ever since they started to bloom pollinators have been swarming the site. The most popular plant is a self-seeded boneset that’s regularly covered with bees, small wasps and flies. I’ve been delighted to see goldfinches on the cosmos – something I wouldn’t have believed possible until I saw it myself.

Grasses

I could wax poetic about my self-administered course on Ornamental Grasses but enough is enough. I’ve had a very satisfactory Staycation and am pleased to be able to share some of it with you.

What I Learned At The IMGC

Tena van Andel, Toronto

With giddy anticipation and five bottles of local Seattle wine, fellow Toronto Master Gardener, Elizabeth A. Stewart, 998 other Master Gardeners and I walked the gangplank of the Westerdamn ready to experience an International Master Gardener Conference at sea.   Lesson one – don’t call it a ‘gangplank’, it’s a ‘gangway’ and don’t spell Westerdam with a ‘n’.  This will make the crew frown.

For the 16 Canadian delegates, the cruise started on high seas.  We were very loud and proud when it was announced at the Search for Excellence Awards that our very own Thunder Bay MGs had won!  Their very fine work on coping without pesticides caused a collective gasp from the American audience – gardening without pesticides, no way!  Lesson two – although some US MGs and some of the speakers decried the use of pesticides it is still a prevalent practice that will not go away anyway soon.  We, who have been gardening without pesticides for years now, were shocked, smug and then sad.

The conference was a veritable buffet of breakout sessions and keynote addresses.  And, believe you me; by the end of the cruise, I gained much at the buffets -  about ten pounds, in fact!  Lesson three – not everything at a buffet is worth the calories.  About half of my eight breakout sessions were very informative – how to use QR codes in garden education, plant diagnostics, MGs and plant phenology programs and an objective update on GMOs.  Did you know there is a genetically modified tobacco seed that can detect landmines?  Yup, when the plant grows over a landmine, it turns a rusty red colour.  My other breakouts were not so filling.  One speaker actually told us what a perennial is – you know, ‘those plants that come back every year’.  Shoulda spent that session in the Crow’s Nest Bar partaking of the drink of the day (mmmm, strawberry basil bellinis)

It was very interesting how different the American MG system is as compared to ours.  Paid University Extension staff manages most of the groups in the States.  Groups may not be funded, but they enjoy the free resources of university scientists, communication departments, state administrators, inexpensive training and special MG liaisons.  We, by contrast, are totally self-governing.  Lesson four – we should be so proud of what we accomplish as highly motivated, dedicated VOLUNTEERS.

The cruise was wonderful.  We had amazingly sunny weather, saw lots of whales, sea otters, sea lions and bald eagles.  We visited Juneau, the Glacier Gardens with the upside down trees, Sitka, Ketchikan and Butchart Gardens in Victoria.  Just lovely.  However, I’m not sure a cruise ship is the best place for a conference.  They did not have the facilities to host all the sessions they offered.  We had breakouts in the piano bar and in a dark, ‘make out’ lounge – terrible locations for both speakers and the audience.  Even the best rooms suffered during our day of rough seas with seasick speakers and jiggling projectors.  Lesson five – folks who say these cruise ships are so big you never feel them move and have all sorts of stabilizers so you never feel the waves, LIED.

Of course, the best part of the conference, of any conference, is the gardeners you meet.   We met kindred spirits from all over the USA – Florida, California, Arkansas, Oregon, Washington, West Virginia and even a delegation from Korea.  BTW you are all invited to the Korean MG conference next spring.  Lesson six – conferences are the best opportunity to be inspired by other Master Gardeners and to make them friends.   Even with the glaring difference in pesticide policy, we had lots to talk about, lots to learn and lots to look forward to when we meet again at the next International Conference organized by Iowa and Nebraska in 2015.  By then I hope to have lost the souvenir ten pounds!

Mosaicultures Internationales Montreal 2013

Diane Marchese, Guelph and Wellington County

Chameleon With a Closeup

The largest exhibition of horticultural art in the world, staged every three years in a city selected by an international committee, this year's theme was Land of Hope, which aimed to illustrate the beauty and fragility of life on earth.  This year the Montreal Botanical Garden hosted and what a perfect venue it was!

This is when the word awesome is appropriate to use in discussion.  My friend and I stopped so many times just to slowly take in all the aspects of these sculptures.  Many of them like The Man Who Planted Trees was large, encompassing running horses, a herd of sheep, a huge sheep dog and an enormous man kneeling in the act of planting a tree.  They weren't all of this magnitude, a little scaled down were playful pandas or a lone chameleon on a branch embossed with Echeveria secunda 'Glauca' or 'Vert'.

The 3D structures were designed on paper and then realized using steel.  The sculptor-artist-welders formed superb metalwork, checked by structural engineers to make sure the frames would be strong enough to hold the horticultural materials assembled by a crew specifically assigned to the design.  Then there is the upkeep by maintenance people who work seven days a week shaping and watering each structure.  Teams would work together, manicuring their display and then keeping each other in the know as to what needs to be done the next day.  The bottom line I was told by a one of the gardeners is "to find the areas that require cleaning up and trimming before the visitor sees it."

Many of the plants used were different types of Alternanthera dentata like 'Purple Knight', 'Fine true Yellow', and 'Christmas tree'.  Santolinas, Echeveria rosettes, sedums of all kinds and grasses like 'Black Mundo' to name of few.  Close to three million plants were used and they were chosen for their uniformity, texture, ability to tolerate the unique growing conditions, to be trimmed regularly for a bushier look and, most importantly, disease and pest free.  I have a new respect for ground coverings.

Most importantly the pieces made you stop and receive their messages that were so carefully thought out by the designers – from The Woman Who Loved Cranes, based on a true story from China, to the Tree of Birds, with each branch supporting an endangered bird.  The tree symbolizes all the biodiversity that surrounds us and how fragile it is.  This reminds us that we are not more important than anything else in nature and that we should be modest and mindful of our existence within it.

Here is a link to the mosaiculture site. and a link to a number of photos of Mosaiculture Montreal 2013