Aloe species are native to various parts of tropical and sub-tropical Africa, but mainly South Africa.

The best-known kind is Aloe vera, the one used for its healing properties. It thrives in a sunny porch or conservatory or in a greenhouse. The plant has narrow long, pointed leaves, rounded in cross-section and quite thick and fleshy, a true succulent, the fleshy leaves specially adapted to retain moisture.

When a leaf is snapped off for use, the broken end exudes a clear or slightly greenish gel. This is the active substance, cool and soothing when applied, and it seals the skin as it dries.

The plant can be grown in a pot for many years, increasing the size of the pot as the roots fill the space.

When the plant reaches about 40cm, there is a chance that it will flower, producing upright spikes of yellow or greenish flowers, their structure reminiscent of those of the red-hot poker, also native to South Africa. The plant in its pot can be put outdoors in summer but it cannot tolerate frost and can only be put outside between the beginning of June and the end of August.

A few other varieties are better known as garden plants than the true aloe. The partridge-breast aloe, Aloe variegata, was once widely grown because of its convenient habit of producing little offsets that could be easily detached and would quickly form a new plant. The leaves are short, about 15cm, at their biggest and thick, triangular in cross-section. When a few years old and 15cm high, the plant flowers with a tall slender stem, uncannily like some of the smaller red-hot poker species. Also grown as a house plant or in a conservatory, the broad rosettes of Aloe aristata are very pretty. The shape is more like that of the hardy succulent sempervivum but the rosette is much bigger. It has white edges to the leaves and it can be risked outdoors in very mild areas.

The species Aloe striatula is the hardiest and can be grown outdoors in mild gardens. Any garden that has had pelargonium survive the winter would manage this one too, as it is slightly hardier. Ten years ago, the two cold winters killed it to the ground but it re-grew from just below soil and made a fine broad plant by the end of summer. This species is a vigorous branching plant with rosettes like its cousins but strung out along the short almost woody branches, and the leaves are broader at the base and come to a narrow point, dark green. When it is established a few years, it produces short spikes of drooping tubular, yellow flowers, very like those of red-hot poker or knipofia. These last for a few weeks and give a great exotic touch to the garden, especially when used near a paved area.

While this species is the best bet for outdoor growing, all kinds can be used outdoors in summer on a paved area and they benefit from the extra sunshine. If some plants are to be tried outdoors, prepare the planting spot by digging out a deep hole and filling its base with a good thick layer of stones or rubble to improve drainage. This plant does well in a rock garden or raised bed. In a pot make sure to add some coarse sand to the compost to ensure brisk drainage and no chance of water-logging of the soil that might lead to roots rotting. Fascinating plants, not always easy to find to buy, they are worth looking for.

Lengthening life

Trim back lavender bushes

Lavender.

Lavender loves sunshine and warm weather. It is native to the Mediterranean region and finds the climate here a bit too damp and cool most of the time. Well adapted to the dry, exposed and sun-baked hills where it grows wild, the foliage and stiff stems can take constant buffeting of wind without damage. The flowers are carried on slender stems, strong although quite light, and the flowers themselves are carried in a dense spike at the top. The flowering period stretches to June and July

The common lavender makes a small, dense and rounded bush to about one metre tall and a bit more wide in vigorous plants. All kinds thrive in well-drained, poor soil and full sunshine, and tend not to last more than a few years in heavy soil. In dry gravelly soil, self-sown seedlings might appear. After a few years, the bush begins to look somewhat straggly. To keep the bush neat and to lengthen its useful life, trim back all the flowering shoots along with the tips of new shoots when they have finished flowering at the end of July or early August.

This week’s reminders

Fruit, vegetables and herbs

Repeat sow salad vegetables that mature quickly and peas and leaf spinach. Weed control should be kept up to prevent weeds from going to seed and causing trouble in the years to come. If you grow potato varieties that are susceptible to potato blight, you will need to spray in damp weather.

Flowers

Seeds of perennial flowers such as lupins, mallows and foxgloves could be sown now for flowering next year. Bedding plants in pots and baskets will be looking good now but they are also in greater need of regular watering and feeding. Feeding every two weeks or so is essential.

Trees, shrubs and roses

There is rose blackspot disease about and if you grow a susceptible variety, it may be necessary to continue to spray rose bushes, especially in the damper parts of the country. Mildew has also appeared on susceptible rose varieties but they seem to be able to flower just the same.

Greenhouse and house plants

Take cuttings of all kinds of shrubs now, using two parts peat to one part sand and covering with white polythene. Use rooting powder. Continue watering and feeding greenhouse plants. Be especially careful to water plants in pots or grow-bags too easily dry out.

Lawn

After a slow start due to a cold spring, grass got going well during the spells of sunshine and thundery rain. Lawns could probably benefit from a second feed now, but this is not necessary if the growth is already good.

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