Wednesday, 22 June 2011

Pottering Around


Writing a gardening article ten days in advance of publication has its disadvantages. After surviving a really bad winter which killed out many plants, the garden readjusted itself as good growing weather prevailed for a couple of months. Seed sowing, planting, soil preparations and weeding were all back on schedule and I even had time to test the sun lounger. Everything was going so well that it was well worthy of a good gardening article, “Perfect Weather for Gardening”
Fate had other ideas and I now know how Michael Fish felt. The day before my article appeared the gales arrived and blew half the garden away. Good job this is Dundee, as no-one took me to task on my perfect gardening weather. Trees were blown down, my hanging baskets blew off the walls, plum trees lost half their branches, and the end of my greenhouse exploded as the winds bent the structure. Courgettes and pumpkins outside to harden off got blown out of their pots, delphiniums were flattened and any plant with soft spring leaves got shredded including climbing roses, young saskatoon plants, vegetable plants in boxes, shrubs and my new cherry tree and mature peach tree.
However, our unpredictable weather then gave us two days of heatwaves followed by a massive temperature drop turning my greenhouse tomatoes blue as they now have a well ventilated end with no glass. Strawberries are all ripening but lack of warmth reduces the sweetness and softness.
I hope that when you are reading this weeks garden adventure I will be back up to date with tasks and start my pottering around with numerous pleasant wee jobs, interspersed with coffee breaks and wee seats in the baking hot sun.

The Garden

As one display ends another begins. It is now the herbaceous border that is providing the colour with a combination of bright scarlet oriental poppies and blue flag iris. The gales had no effect on them but my new cherry tree, already suffering from an attack of black fly got its leaves shriveled, as did my plum and peach trees.
Poppy seed sown in many bare areas is germinating strongly and promises to give a good display.
My climbing roses, Dublin Bay and Gertrude Jekyll lost half their leaves in the gale, but are still putting on a decent display of flowers.
Cornus (dogwood), and Salix (willow) in the coloured stemmed winter border have both put on strong growth even after I cut them back right to ground level in March.

The Allotment

Strawberry picking is now a major task with a huge crop on all varieties. Gooseberries are also hanging heavily despite a thousand sawfly caterpillars mounting an attack when they thought I wasn’t looking. Black and red currants are also laden heavily with berries, already turning colour far earlier than normal. Nets will be needed for the red currants, but not the blacks.
Thinning turnips, swedes, chard and lettuce is at the two inches apart stage, but my thinly sown beetroot won’t be thinned till I can get thinnings as a baby beetroot crop. I do not thin leeks, spring onions or radish as they are sown thinly. Parsnips have germinated perfectly this year.
Chrysanthemums, sweet peas and gladioli planted out for cut flower and display have all established well as we have had good growing weather apart from the gales.
One area intended for a June planting of pumpkins, courgettes and cape gooseberries had been sown down with a mustard green manure crop to improve the soil fertility. This is now three feet tall and beginning to flower so it will be trampled down and dug in. It is best to dig with a trench so you can bury the green stems easily. They do not regrow once buried. It is an extra task, but has a really beneficial effect on the next crop. It is very worthwhile at the beginning of the growing period for late planting crops and also at the end after harvesting an early maturing crop such as broad beans, early potatoes, peas, salads and sweet corn.

The Greenhouse

Young vegetable plants left the greenhouse to get hardened off, then promptly returned as the gales blew in. Unfortunately it was too late for my courgettes and pumpkins which got shredded and blown out of their pots. I may be able to salvage some of them with a bit of luck.
Tomatoes were growing strongly, and flowering profusely before the gales blew out the glass. Now they are a bit cold but in time they should be ok.
Grapes now need constant pruning as every young shoot gets cut back to one leaf, as I can now see the bunches on the laterals growing from each rod.

Gardening Scotland
I have always attended this June event at Ingliston in Edinburgh as well as the Dundee Flower Show at Camperdown Park in September. However I now take a stand at these events to promote and sell my Saskatoon plants. They are becoming very popular as I was nearly totally sold out, only bringing back one plant. We also get the chance to look around other stands. Anna could not resist a gorgeous Peonia Doreen so it will now find a favoured spot in the garden. I really liked this Arisaema sikokianum, but was told it was a bit evil looking and a wee bit too much like a triffid, so I had to settle for a new rose for my garden hose. Life can be hard at times.


Friday, 17 June 2011

Dundee Botanical Gardens


The Botanical Gardens in Dundee is a unique asset for our town. It has developed along a different route from other Botanical Gardens. While it is a fantastic place to wander through enjoying a wealth of diverse plants from all over the world, it also serves to educate children, students and scientists in ecology, biology and the environment.
It celebrates its 40th anniversary this month, and hopes to continue for many more years, but in these times of recession and cut backs funding for the future is always an issue.
The Botanical gardens started life on a very restricted budget, but this was turned into an asset as management of the natural environment as influenced by man was kept to a minimum.
However, as a horticultural enthusiast I enjoy looking at the beauty of natural landscapes, the smell of plants, not always found in garden centres, and finding rare and unusual plants, (all with named labels) that are usually only found in horticultural training colleges or botanical gardens.
There is a massive range of plants from mature trees to rock garden plants, tropical, temperate, rain forest and desert plants.
When studying horticulture during my apprenticeship days, knowledge of plants came from books in the Kingsway Technical College library. It would have been brilliant if this garden had been available to see all these plants and learn about them in a natural environment.


The gardens were started in 1971 by Dundee University to meet the needs of the botany staff.
The site chosen had a gentle southern slope, good soil, and a burn with very pure water coming from Balgay Hill running from the top western corner down through the gardens. This assisted the creation of several water features. It had great potential though initially it was quite barren and needed a lot of new plantings related to local needs.
The first curator was Edward Kemp whom I recall gave a lecture at Pershore College in the late seventies about how he was establishing a natural Scottish environment at the gardens using the south facing slope. This helped to establish a mountain flora at the top slowly changing by altitude to a seaside environment at the lower end, but going through other natural plant associations as you went down the slope. It was quite fascinating.
In 1980 Les Bissett became curator and established the new visitor centre. He brought with him a fantastic knowledge of plants.
The current curator Alasdair Hood arrived in 1998 and is concerned with promoting the gardens to increase visitor numbers and the education facilities for children, schools, colleges, university students and scientists studying biology, conservation and other plant sciences.
Education even extends to the establishment of a typical allotment garden, though some work needs to be done to bring it up to City Road Allotment Garden standards.


This starts with toddlers who love to explore and discover where the tea and coffee comes from and what a banana and orange tree looks like. School children can study botany, see how plants grow, spread, defend themselves and reproduce and see local wildlife around the garden.
Facilities for teachers, students and scientists studying plants and their habitats and special research projects can be arranged.

Visitor Centre

Ample car parking allows for the increasing number of visitors to the gardens. Get advice on plants, garden problems and book a guided tour of the garden at the visitor centre. The visitor centre hosts a frequently changing art exhibition of local artists (I will be holding an exhibition of recent paintings in mid October), as well as an excellent cafe and plant sales area.


There are two greenhouses. One is for tropical rain forest plants and the other for plants needing a desert habitat. Here you can see tea, coffee, oranges and bananas growing, and a giant water lily.
A wee bit of garden violence is provided with a good collection of insectivorous plants that feed on insects. The honeydew has a sticky secretion on the inside of its leaves. When an insect gets bogged down and begins to struggle the leaves fold over it so it cannot escape. The pitcher plant has long funnels with slippery sides and downward pointing hairs. Insects are attracted to it seeking some sweet nectar. Unfortunately, there isn’t any, but once they go into the funnel they can’t get out and slowly weaken and fall to the bottom of the funnel where they drown in a watery fluid full of digestive enzymes.

Natural Environments

The garden has developed over the last forty years as a place to study plants from all over the world growing in their own natural environment as much as the Dundee soil and climate will allow.
The shelter of the north west slope behind the glasshouse creates a drier environment suited to herbs and Mediterranean  plants.
At the other end of the garden plants from Australia and New Zealand which also enjoy a drier climate are well represented with some excellent mature Eucalyptus species, shrubs and ground cover plants. I really appreciated finding a Hebe macrantha with large white scented flowers, a plant that we grew in the Parks Dept nursery at Camperdown, but I had never seen since.
Another area hosts plants native to the Americas with some impressive giant redwoods.
Plants native to Scotland have a special area of mountain, glen and burn, and the specimen of Camperdown elm is the strongest and healthiest I have ever seen. It does not grow very tall as it has a strong tendency to weep.
A new section to show plant evolution from mosses to flowering plants has been created in a series of dry stane dykes which meander around leaving behind planted beds showing the different stages of plant evolution. Those dykes are very impressive showing that they can be very strong as well as ornamental allowing the builder ample scope to be as creative as he/she desires. They are a fantastic piece of pure stone mason craftsmanship.


Tuesday, 7 June 2011

Tuberous Begonias


Tuberous begonias are one of the most reliable summer bedding plants, providing a wealth of large blooms in any weather in just about any colour except blue. They are perfect for bedding, tubs, window boxes, hanging baskets and as a house plant on a sunny window sill. They are also used extensively by exhibitors at gardening and flower shows.
The flowers are usually double and can be frilled and some have a beautiful picotee edge.
Once you have grasped their basic cultural needs for growing and storage they will last for years. I purchased my tubers about fifteen years ago and at the end of each season I have more than I started with as the tubers grow larger. Protect them from frost at all times as they are half hardy.
It is usual to use different varieties suitable for summer bedding (doubles, Non Stop, Frilled, Picotees), those with a trailing habit for baskets (pendulas), and those with large bright flowers for showing (expensive upright doubles). You can pay up to £30 for one tuber of the best variety, whereas tubers for bedding are about £1 to £6 each. They may be expensive to start off with, but they last for years and slowly increase in size.

Early training in Begonias

Away back in the mists of time when the Dundee Parks Dept had numerous apprentices, (here we go again) we were trained to grow begonias to exhibition standards. Our head gardener at Duntrune Terrace training gardens grew them for exhibition at the Dundee flower Show. It was absolutely essential, we were told, to line the inside of the clay pots with fresh cow manure. Apparently only fresh manure would stick to the pots, not to mention the apprentice’s hands. So a wee trip to the countryside was arranged for some unsuspecting young gardeners early in the morning before our ten o’clock tea break. We never forgot how to grow exhibition begonias.
However the begonias were terrific all summer and I needed to get my hands on some for my own garden. An apprentice’s pay does not stretch to the purchase of tubers which at that time cost a fortune, but I could afford a packet of seeds from the country’s specialist grower of begonias, Blackmore and Langdon from Bath. These arrived one January, were sown immediately according to our resident head gardener and I subsequently obtained a small crop of about fifty tuberous begonias. These all flowered that summer and the tubers lasted for years.


Plant collectors brought back the first begonia species from Bolivia and Peru in the nineteenth century, but these plants only produced a few small flowers on tall plants. Breeders starting crossing the species, selecting the best plants and slowly over time the begonia began to improve. At the beginning of the twentieth century a partnership of two amateur growers got together and formed Blackmore and Langdon of Bath. They produced hundreds of seedlings to sell to other nurserymen. They also exhibited successfully in London and have continued hybridising begonias ever since.


Although cuttings can be taken and root fairly easily, the plant does not produce many sideshoots for cuttings nor are there many initial shoots on the sprouting tuber to take. It is also possible to split the tuber in April when emerging shoots are quite prominent. You need at least one or two shoots on each piece, but this is a very slow way to bulk up stock.
Seed sowing is the best way to produce a lot of plants quickly.
Sow in January to February on finely prepared seed compost. Do not cover the seeds as they need light to germinate, but to retain a moist atmosphere cover the seed tray with glass. Turn this over daily to remove condensation. . They must always be moist, but never wet and need a constant temperature of 65 to 70 F. to germinate. Always water by immersion from the bottom. The seed is very small and the seedlings are equally small, so when big enough to transplant you will need to make a forked stick to lift them out together with a very small dibber. Do not handle seedlings with your fingers. Plant them in trays about 4cms apart and once they fill those, transplant them again into larger containers. Young seedlings are quite tender and may be damaged by strong sunlight, so shade for a few months till they get a bit hardier. They should be big enough to plant out in June.


Dry tubers are started into growth by placing them close together, concave side up in shallow trays of compost in January or February. Cover them with compost but not too deep. They need a temperature of at least 65 F. Once the sprouts begin to grow and need more space, replant them into larger boxes or pots. Keep them watered and fed. Harden off by mid May and they should be ready for planting at the end of May or early June.
I plant out my begonias in beds at about a foot apart as my mature tubers now grow into quite large plants. They do not need staking, but if you are growing for exhibition you will need stakes as the large flowers are quite heavy.
The plant produces one main large male flower together with two smaller female flowers at the end of each flowering shoot. The smaller female flowers only need to be removed for exhibition. It is not necessary to remove them in a flower bed or tub. They are gross feeders in tubs, pots and baskets and need constant watering, but will reward you with a fantastic show of colour right up till the autumn.


At the end of the flowering season, about mid October, cut back the plants to about three or four inches and lift them carefully. Knock off any loose soil and store them in an airy dry cool but frost proof place. Let the soil around the tubers dry out and fall off. Store them in boxes concave side up covering them with the dried out soil or old potting compost. Make sure it is fairly dry.
Keep checking them to make sure they are still dry but firm.
Some time in late February the buds will begin to grow, so then it is time to start them back into life.


Monday, 6 June 2011

Gardening on a slope


Dundee town has grown around the Law Hill, Balgay Hill and even Menzieshill, so there is a fair bit of steep slopes incorporated into housing development land.
The challenge of a sloping garden will vary according to the degree of severity, the type of soil and whether the slope runs towards the house or away from it. Slopes can create a dry garden by allowing surface water to run off it, or a flooding problem if you are at the bottom of a hill. Problems of steep sloping gardens are usually left by the builders for the house owner to solve. However if the slope is severe and runs towards the house the builder is most likely to have tackled any potential drainage problem which could affect the property.  However it is always a wise move to check the property to see if there is any history of flooding or water damage.
For every negative aspect of a slope there is always the positive side. You may be blessed with a burn that can create a fantastic water feature garden. A rock garden  is perfect on a well drained slope. Many plants look better if viewed from below e.g. Fuchsias, Lilies, Himalayan blue Poppies, and some better if viewed from above e.g. Tulips.
The slope allows terrific scope for gardening creativity in both soft and hard landscaping so take time to consider all aspects before getting the spade out.


If your garden is at the bottom of a slope, surface water causing local flooding after heavy rainfall could be a problem. Wet soil may be indicated if you see a lot of moss, sedges or buttercups. It may be sufficient to cultivate deeply to allow water to percolate through the soil, but if the flooding risk is high consider some garden drainage. This could be a simple drainage system of perforated pipes under a gravel path leading to a decent sized soakaway. A more ambitious project may be necessary with professional advice needed on depth, type and size of perforated pipe, backfill material, extent of run and connection to an outlet. If using a surface water outlet the connections are critical and must be done properly incorporating a catchpit so that garden silt or debris can be filtered out in a sump to be cleaned out periodically.


After drainage, good access must be incorporated into the design to allow for weeding, planting, pruning and wandering around enjoying the garden. There must be plenty of flattish areas to work from connected by a path network. Strategically placed large bushes and trees can help to hold onto to assist stability. Footpaths on very steep slopes are best with a handrail for safety.
A path system may be formal with slabs, bricks, and breezeblocks, or it can be sympathetic to the landscape with natural wood risers backfilled with course wood chips. A trip to a builders merchants yard who specialises in hard landscaping can give many ideas to work on.

Retaining Walls and Terracing

Really steep banks may require retaining walls next to footpaths, but terracing with large rocks will give a more natural appearance. Good quality natural stone can often be acquired from builders yards if they have been doing any demolition of old buildings, or it may be purchased from a local quarry. The size of the job will determine whether it is done in house or whether a bricky or stone mason is employed. There are plenty of excellent dry stone wall builders who can create an attractive wall with strength. If cost is a factor breezeblocks can be used for speed and strength. Their formal appearance can be softened with ground cover plants allowed to trail over the edge.
Make sure any walls are strong enough to retain the bank for at least 50 years and provide weep holes for drainage.
Terracing is very useful to break the bank into a series of flat areas held up by as big rocks as you can find. During garden maintenance you will want to scramble over these rocks without fear of them toppling over, so size is important. A JCB may be needed to move big rocks around. Try to create a series of natural looking rock faces with the rocks relating to each other. Bury at least two thirds below ground. Create a series of plateaux  by cut and fill over the slope.


This can be an important option to create a flat patio adjacent to the house on a steep bank. Often there will be space left below the decking as the slope falls away. This is useful for storing garden tools or given over to the kids as a den to play in. Much safer than a tree house.
 Make sure your patio enjoys plenty of sunshine, some privacy and shelter from winds. Decking has been in fashion for a few years now, so there is plenty of information on materials, construction methods and maintenance of the wood. Make sure it is strong, the wood is well preserved and the design safe.

Plants for soil stabilisation

Once the slope has been hard landscaped, the planting can now be thought out. Terraced slopes and walls allow a fair bit of easy planting at waist height, so these areas can be more intensively gardened. Other areas of steep slope may be better with permanent planting, choosing plants that can hold the soil together to prevent any erosion.
I garden on several very steep banks with a fair degree of walls and terracing. Over time some plants prove much better than others in binding the soil surface together.
My favourites include Flag Iris, Delosperma, heathers, London Pride, Euonymous, variegated ivy, numerous dwarf spreading conifers, Shasta daisies, fuchsias, rhododendrons, azaleas and hostas.
For the larger garden use philadelphus, saskatoons, ceanothus, viburnums, kerria and cornus.
It always helps if bulbs can be interplanted as they can be very good at naturalizing. Bluebells and grape hyacinths are some of the best.