IRIS

IRIS

I first came across irises when I got my first allotment garden at Stirling Park on the side of Dundee’s Law Hill. There was a beautiful row of blue coloured English iris well established along the main garden path. To add to the show I had bought some Dutch iris bulbs though these flowered after the English iris. Later in 1969 while studying at Essex Institute of Agriculture in Chelmsford we got involved in breeding flowers of the large and very colourful bearded iris. I got hooked and now iris is on my must have plant list.

Bearded iris

Iris comes in a range of types and sizes. The most popular are the tall bearded iris, Iris germanica, also known as flag iris with thousands of different varieties available most of which are scented. They are always available in garden centres, though there are several specialists where you can get the very best varieties but usually at a higher price. These iris grow from rhizomes and are best planted in autumn. They like to be in the sun in fertile soil that is well drained and either neutral to slightly alkaline in pH. When planting keep the rhizomes on the soil surface as they will rot if planted deep.

Established clumps will need splitting up and replanting every three years or so.

English and Dutch Iris

The English and Dutch iris grows from bulbs, usually planted about six inches deep in autumn.  The yellow, white, purple and blue flowers open in summer growing up to two feet tall. The English types are very hardy and can be left to form large clumps over several years before they need lifting and replanting. However the Dutch iris are best treated like a tulip by planting them in autumn, then lifting them in summer after the leaves have died down. They can be stored in a cool shaded place.

Bog and pond garden iris

Although most iris prefer drier soil and a warm sunny sheltered spot there is even an iris for the less sunny and more moist  garden. Iris sibirica prefers a more permanently moist soil associated with pond fringes, but do not plant it in very wet soil otherwise it will rot.

Iris sibirica flowers in summer with blue, purple and white flowers up to 2.5 feet tall.

Rock garden iris

The rock garden is also well catered for with a range of dwarf irises most of which flower in late February to March. These all prefer a well drained soil in full sun and it is important that the ground is very well drained in winter. It is a good idea to incorporate grit as well as some well rotted garden compost into the soil before planting. Iris reticulata and iris histrioides grows about six inches tall with blue flowers. Iris danfordiae grows the same size but has yellow flowers.

Plant of the week

 Kaffir Lily (Schizostylus coccinea) is also related to the iris family. It is a semi evergreen herbaceous perennial growing in clumps about 24 inches tall with white, pink and red flowers in late autumn and early winter. It prefers moist but well drained fertile soil and a warm sheltered aspect in full sun. It is fairly hardy in most winters.

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TRY A DIFFERENT BERRY

TRY A DIFFERENT BERRY

Plant breeders are always coming up with some new form of plant by experimenting with cross pollinating one type of plant with another. It is fun to try out something new or different and it always creates an interesting talking point for those with an interest in gardening. There is a wide range of new types of fruiting bushes available as well as improved forms of all our standard varieties.

Blackcurrant breeding has been going on at the James Hutton Institute for a long time creating the “Ben” series with my favourite being Ben Conan with huge fruits. However breeders have now created a blackcurrant with an even bigger and sweeter berry called Big Ben that may well temp us to eat it fresh from the punnet like a strawberry.

My Big Ben blackcurrant bush had a very small crop this summer, but not enough to judge.

Gooseberries are also being improved with mildew resistance now normal, and thornless types to make picking easier coming soon.

Raspberries have had a lot of attention with new types of autumn fruiting varieties such as Joan J, Autumn Treasure and Polka claimed to have massive sized berries. I am trying Polka but so far it is no bigger than Autumn Bliss though I need a few more seasons to assess it.

Blackberries have also had the attention of the breeders, initially interested in creating thornless types. This is now normal but interest now involves primocane types to fruit on canes grown the same year. The new variety of primocane blackberry Reuben is said to have immense sized fruit ripening from September to November.

Worcesterberries are a cross between a blackcurrant and a gooseberry. The medium sized fruit is very sweet and tasty but the bushes which can grow quite tall have vicious thorns.

Jostaberry is another similar cross with black coloured fruit tasting and looking like both gooseberry and blackcurrants. It grows up to two metres tall and the fruit is easier to pick as the bush is thornless.

Honeyberries are a medium sized, hardy, deciduous shrub. This blue fruiting honeysuckle is relatively easy to grow but it flowers very early in the year when there are very few pollinating insects around so hand pollination may be necessary to achieve a crop.

Goji or Wolfberry has been grown in vast acreages on the fertile floodplains of the Yellow River in China for hundreds of years. Unsubstantiated health benefit claims created a huge demand for the fruit. It is a vigorous deciduous rambling shrub which will eventually produce orange fruits. I have tried unsuccessfully to get several of these to fruit over the last six years but with no success. However my rampant bushes ten foot tall did not survive the mild winter, though this might be an infection of the root rot phytophthora, which I seem to be plagued with.

Japanese wineberry is a type of ornamental raspberry. It grows and fruits like the raspberry having delicious sweet fruits, but is not common. It is quite attractive in winter with its bright red stems.

Saskatoons, also known as Juneberry is the fruiting form of the Amelanchier and native to North America. They are very hardy and easy to grow. The fruit is similar to the blueberry, but fruits at the end of July while the blueberry fruits in August to September. Saskatoons are eaten fresh in season or can be frozen for use later in jams, compote, cakes and brews into a brilliant wine.

Plant of the week

Day Lily (Hemerocallis) is an herbaceous perennial flowering from spring to late summer depending on type. It has been extensively bred to produce every colour except blue and pure white. Some types are scented. They like most well drained soils and will tolerate dry conditions and to get the best flowers give them a place in full sun.

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AUTUMN PROPAGATION

AUTUMN PROPAGATION

September and October are great months for propagating all sorts of plants. They have had their summer growing period and now stems are beginning to harden up ahead of the winter, but there is still enough warmth left to keep parts of the plant active. Roots can continue to develop at this time of year. Many flowering and fruiting shrubs can be propagated by hardwood cuttings taken immediately before and just after leaf fall. Herbaceous plants can be divided and replanted in autumn and many annuals are ready for harvesting seed pods to save our own seed for sowing next spring. Now is also the time to take cuttings of geraniums and impatiens from the best varieties to root at home and over winter on a windowsill or in the greenhouse if it has some heat.

Hardwood cuttings

This is a very busy time for nurseries that produce a lot of their shrubs from hardwood cuttings.

Cornus, senecio, cistus, lavender, rosemary, forsythia, philadelphus euonymus, viburnums and hundreds of others will all root from a cutting about four to six inches long, removing the lower leaves and making a cut under a leaf node or with some such as pyracantha pulling off the shoot with a heel. These are then lined out in trays or in a cold frame bedded in a propagation medium (mixture of half compost and half sharp sand or grit.) Keep the compost moist and the frame well ventilated in sunny weather. Plants should be well rooted and put on some growth by next summer when they can be carefully removed and either potted up or planted out.

Blackcurrants and gooseberries can also be done this way, though they do not need the protection of a cold frame.

Divide herbaceous plants

Flag iris, oriental poppies, heleniums, Shasta daisies and many others can be lifted, divided and replanted. Add compost and some fertiliser at this stage. Heucheras can be propagated by pulling off sideshoots and using them as cuttings in a cold frame or greenhouse. They will root in a couple of months.

Collect seeds

Poppy ladybird, Himalayan blue poppies, other poppies and annuals that produce viable seed pods can be harvested for their seeds. Dry off the pods and extract the seed storing them dry but cool.

Summer flowers

Geraniums and Impatiens can be propagated by cuttings taken now. Geranium cuttings of about three inches long snapped off the plant and potted up will root after a few months and can be over wintered on a sunny windowsill. Keep them frost free and cool, but if you wish to produce more plants grow them warmer and feed them. As soon as they are big enough take out the tops and use these as extra cuttings.
Impatiens are even easier as cuttings three inches long with all lower leaves removed are dropped into a jar of water. They will root in about six weeks and can then be potted up.

Both these plants are suitable as flowering house plants in early winter then again in spring.

Plant of the week

Gladioli have been at their best for several weeks. They can really add colour, impact and height to flower borders and it is possible to pick up bags of really good corms very cheaply.

The corms are lifted and dried off to store over winter in a cool dry place free from mice and each year you can add a few more corms of different varieties.

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TIME FOR A TIDY UP

TIME FOR A TIDY UP

The summer fruit, flowers and vegetables have all had a great time, but autumn is not too far away so now is a great time to get the garden totally cleaned up before the leaves start to fall. Some weeds such as groundsel and pennycress keep germinating well into autumn so take the chance of any dry days to remove them. There is still time to tackle any perennial weeds with a glyphosate weedkiller, but it needs plenty of leaves to absorb the chemical so it can translocate it down into the root system. This chemical needs a couple of dry days to work. It is not taken in by the roots as the chemical is deactivated by contact with the soil. Some serious weeds such as mares tail will need a repeat dose after a couple of weeks.

Most summer fruiting strawberries are well past fruiting so the foliage can be cut back and removed together with any straw laid between the rows. This can all be composted, though some of the straw is perfect for placing under pumpkin fruits. As these grow larger it is good to keep them off the bare soil to keep the skins clean.

On the allotment make sure any rows of fruit or vegetables such as cabbage, sprouts, swedes and autumn salads are kept weed free, but other areas where crops are finished can be left as weeds can be dug in during the late autumn digging.

Blackcurrants, redcurrants, saskatoons and gooseberries as well as summer fruiting raspberries have all finished fruiting so pruning can be done at any time. It is not necessary to wait till winter when all the leaves are off though this does make it easier.

If you have access to a shredder the prunings can all be shredded and added to the compost heap.

Gladioli, early flowering chrysanthemums and sweet peas grown for cut flower can be cut as they flower. Sweet peas benefit from flower removal to encourage more to grow.

Other summer flowers such as geraniums, roses, cosmos and poppies will continue to flower as long as you remove any seed heads as soon as the flowers fade.

Grow a green manure crop to increase soil fertility.

Many summer crops such as courgettes, peas, beans, potatoes, onions, brassicas, sweet corn and salads are now finished so there is time to sow a green manure crop to get some growth before winter. These can be dug in during winter or some such as tares can be left till early spring then dug in. Green manure crops have strong root systems that help to break up the soil creating a fine crumb structure to improve drainage and once they break down they add a lot of humous to the soil. Many types such as the clovers have nitrogen fixing nodules on the roots which absorb atmospheric nitrogen and fix it onto their roots. This is released on breakdown as a nitrogenous fertiliser to improve the next crop.

 

Tidy up herbaceous border

Delphiniums, oriental poppies, flag iris and many other plants have now all finished flowering so foliage can be cut back and tidied up. Remove any supports, canes and strings and any weeds previously hidden by the foliage.

Plant of the week

Hydrangeas are an easy popular deciduous shrub flowering in mid summer. They can grow quite large in time but different species can vary and the climbing hydrangeas can be quite rampant. The blue flowered types prefer an acid soil and the pink and red ones prefer soil with a higher pH. To intensify the blue coloured flowers you can use a blue colorant chemical containing aluminium sulphate.
Pruning to remove dead flower heads is normally all that is needed, other than removal of straggly shoots. Propagate by taking cuttings of non flowering shoots in summer and autumn.

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