Gardening with Gerry: yucca me feeling tropical

Name: Spanish dagger, Adam’s needle, yucca and Joshua tree are common names used for members of various species of yucca. These are mostly outdoor plants with one species being the commonly grown plant, with woody stems and a rounded top of spiky leaves. As a house plant, it often grows too tall and this species, Yucca elephantipes, is not for outdoor use because it is not hardy.

Botanical name: Yucca is the name derived from the localities in Mexico and the southern United States, where it occurs. Some species of yucca have woody stems and grow tall, such as Yucca recurvifolia and Yucca gloriosa, both of which can reach about two metres and both of which are hardy; tolerating normal winters. Others have no stem, or a very short stem, making a large rosette which sprouts smaller side rosettes that later develop. Such species include Yucca filamentosa and Yucca flaccida. Both of these species have curling threads at the edges of the leaves. All of these species are capable of flowering in gardens, although they may take a number of years to reach flowering size.

Family: Yucca is part of the Agavaceae, closely resembling the taller agave, or sisal. The core of this plant is juicy and packed with sugar (which is used for making tequila), and the stringy leaves provide the fibre known as sisal. More recently, agave has been subsumed into the greater lily family, the Asparagaceae.

Garden value

Quite a sight in flower, yucca makes one of the biggest of garden flowers, towering upwards often to over two metres. The flower spike is a solid structure, many branched, carrying scores of bell-shaped flowers. These hang down, mostly, and the stems are crowded with flowers. The flowers are mostly carried in late summer and into autumn, Yucca gloriosa, the Spanish dagger, being later than others. The flowers of Yucca whipplei are arguably the most beautiful, with very delicate, white flowers on light branches at right-angles to the bolt-upright stem. They can be creamy or slightly purple-flushed too, and they are fragrant. It has narrow leaves. This species takes a few years to reach flowering size, five or more, and then it only flowers once, expending all of its energy in a massive floral display and then withering away.

Growing yucca

Try any of the kinds mentioned in full sunshine with fertile soil and excellent drainage - even a bit gravelly or sandy, which helps against frost, too. Be careful, as some kinds have a sharp tip at the end of the leaves. The variegated kinds are not as attractive, nor do they flower as well as the green forms. Watch for snails, which hide amid the leaves, feeding on leaves and often on the sides of the flower stems which can cause distortion with curving stems and spoils the effect.

Growing blackcurrants

A much-neglected fruit crop, blackcurrants have begun to regain popularity as chefs de cuisine once again begin to value their rich, tart flavour for (traditionally) jams, but also coulis and other uses, such as yoghurt.

The fruit has many health benefits, including high levels of Vitamin C and antioxidants.

Blackcurrants are easy to grow and a single bush can satisfy most domestic requirements. Although blackcurrants, Ribes nigrum, are native to central Europe and southern Siberia, they can suffer frost damage to the flower buds because they flower early enough to be hit by a late frost in May. However, modern varieties have much better frost resistance. The Ben series of varieties were bred in Scotland, with the objective of frost resistance paramount. The variety ‘Ben Connon’ is a good example with large, succulent fruit.

Choose a position in sunshine and good, ordinary soil. Allow the bush to have two metres diameter of space all around. No pruning is needed for the first two or three years. Then, remove a few older shoots each winter. In spring each year, apply some garden compost and chicken manure pellets to maintain good figure.

The crop can be picked over a period of weeks in late July to mid-August (some varieties ripen early and others late), and can be stored by freezing for use during the winter months. Alternatively, jam and other products can be made and also frozen.

Trees, shrubs and roses

Early flowering shrub roses and ramblers could now be pruned by removing some of the shoots that flowered. Many established trees are showing early autumn colouring, which is strange given the plentiful supplies of water, but there has been very good growth.

Flowers

Stay ahead of weeding in flower beds and borders. Prevent weeds from going to seed now. It is possible to collect seeds of perennial flowers, if desired, to raise some new plants. Take cuttings of tender plants such as geraniums, fuchsias and African daisy.

Fruit, vegetables and herbs

Raspberry canes that have finished fruiting may be pruned out and the new canes tied into position. If there are too many canes, reduce the number to about ten or fifteen per metre of row. Summer pruning of vigorous apple, pear and plum trees could still be carried out.

Lawn

With all the rain and sunshine, most lawns have done quite well with very even growth due to lightning releasing nitrogen from the air. If you have a wildflower lawn, consider cutting the heavy hamper to give the grass a chance to become a good dense sward before winter.

Greenhouse and house plants

Continue to train and side-shoot tomatoes and cucumbers. Take the tops off tomato plants to boost the green fruit that is already present. Tidy up all kinds of plant debris and don't overwater, but continue watering and feeding greenhouse plants for a few weeks still.

Read more

Gardening with Gerry: there's garlic, and then there's society garlic

Gardening with Gerry: tempting lucifer