The search for a blue rose is not really due to any great clamour of demand from gardeners, although 50% of people claim blue as their favourite colour. It is based upon the idea that great commercial success will accrue to whoever can first bring out a true blue rose.

Perhaps there is some measure of truth in the theory of great riches for the breeder who clinches it. Blue primroses have been bred and are reasonably popular. However, they look a bit miserable in spring when the weather is often dull and damp.

Blue petunias have had better success. Though more shades of violet than blue, they are blue enough for most purposes, and the lighter tones are the most convincing. These have proved successful in commercial terms as the plants have been popular and are subject to Plant Breeders’ Rights royalty payments.

But then there were always purple or indigo forms of petunias and it is part of the potato family, many members of which have blue flowers, such as solanum. It is much easier to breed in a colour if the family already have the capacity, at least in some members, to produce the colour.

Delphinidin is the blue pigment that gives blue colour to delphiniums and pansies. And there are related chemicals that give blue colour to other plants and fruits, such as blueberries. However, roses do not have this pigment. Some roses are purplish and the aim of breeders has been to keep on selecting until blue develops, without success so far. But things have changed in the plant breeding business in recent decades. Genetics can now pinpoint genes for the production of colours and those genes can be transferred between species. This is changing the goalposts by comparison with traditional cross-breeding and selection.

The Japanese drinks company, Suntory, has many interests in plants and funded a breeding programme to genetically engineer a blue rose. The scientists successfully moved the genes for the blue pigment delphinidin from a pansy into a white rose. However, the rose kept on making small amounts of other pigments and these tinged the blue to pale lavender. Next the geneticists tried to suppress the genes that produced these pigments. Again, the results were not quite a total success, as the pH of rose petals is more acidic that pansy petals and the delphinidin is known to react to acid, a bit like litmus paper that changes colour in acid or limy solutions.

The Suntory rose, Applause, was eventually released for sale but did not sweep the boards.

There have been other claims for blue roses. The old German variety, Veilchenblau, starts out red-purple and the petals fade to a dirty purple-mauve colour just before they fall.

Blue Moon is a previous contender for the title and not hugely different to the genetically engineered variety. It is a bedding rose that produces pale lilac to mauve flowers of a fairly light colour. It is not a bad variety of rose, repeat flowering all summer and scented, but it is a bit sombre and dull, and definitely not a real sparkling blue. The most recent contender for the blue rose title is Rhapsody in Blue, (shown in the picture) and at least part of its appeal is the inspired title. This is a cluster-flowered rose bush or shrub rose. It can be used as a wall climber too. Its flowers are wine-purple to start with but fade to murky shades of blue-purple, a slatey colour.

It is far from true blue, but it has a tinge of blue-purple and it is an attractive rose that has gained quite a lot of popularity in recent years, resurrecting the blue rose debate.

Beetroot picking

Beetroot has undergone a complete rehabilitation in the last few years as people rediscover its eating qualities compared with bottled pickled beet, traditionally used in salads. The flavour and versatility of fresh beetroot has greatly increased its popularity, as has its relative ease of growth. There are rarely any troubles with pests or diseases – pigeons don’t nibble at it and there are no caterpillar foes, not even slugs are too enamoured with it. Bolting is lessened or avoided with newer varieties. But it is easy enough to allow the succulent young roots to get too old and become somewhat woody. Avoid this by sowing seeds two or three times and picking from when the roots are golf-ball size. It can be cooked and frozen for soup later.

Fruit, veg and herbs

Sow a batch of the salad vegetables that mature quickly and some Swiss chard for next spring. Don’t let weeds go to seed. Plant out winter cabbage varieties, if not already done. Spray for apple scab once more if the weather is wet. Harvest herbs for winter use as they come ready by drying or freezing.

Flowers

Pots and baskets need regular watering and feeding. Feeding with liquid feed every two weeks or even every week is essential to keep the plants going after the first flush of flowers. Seeds of perennial flowers, such as lupins, tickseed, mallows and foxgloves, can be sown now for flowering next year, but do not delay.

Lawns

Keep up regular mowing, easing off if the weather is dry. Do not feed the grass if the weather is dry as it runs the risk of scorching. If clover, daisies and the like have built up in the last few years, and you do not regard them as desirable wild flowers, apply a lawn weedkiller during a fine spell, when growth is active.

Trees, shrubs and roses

After a spell of wet days, it is necessary to spray rose bushes, especially in the damper parts of the country, but not otherwise. Early flowering shrub roses and ramblers that have now finished could be pruned. Water young trees and shrubs if they look like they need it, applying about 20 litres per plant at a time.

Greenhouse and house plants

Continue watering and feeding all greenhouse plants to maintain strong growth. Especially water plants in pots or grow-bags regularly. Train and side-shoot tomatoes and cucumbers. Take cuttings of deciduous shrubs of all kinds – especially roses and clematis. Pot on house plants as necessary.