Pumpkins and squashes are native to the tropical Americas and to fully ripen their fruits require a fairly long summer growing season. Their leaves turn black and die with almost any hint of frost and the plant does not do well when conditions become cooler so it is very much a summer crop. All of the large cucurbit family to which pumpkins belong do best if they do not encounter setbacks in their growth, so it pays to treat them well and pay attention to their fairly modest requirements.

The sweet potato, or kumara was grown in the milder districts of New Zealand by Maori from very early times. Traces of their kumara gardens and storage pits can be seen in many parts of the country. The kumara is not a close relative of the potato, the chief resemblance between the two is that they both produce edible underground tubers.

Varieties of sweet potato are grown throughout the tropical world, originating in South America. The sweet potato, Pomona batatis, is frost tender and should not be planted until all dangers of frost have passed. Kumaras do best in a sandy, well-drained soil in a warm sunny, sheltered position. Humus dug into the soil will improve the crop, but it needs to be well rotted and mature: fresh manure and too much fertiliser will cause the plants to make too much top growth in expense of the tubers.

The two main passionfruit met within New Zealand are the black passionfruit Passioflora edulis with dark rounded crinkly fruit, and the Passiflora mollissima, the banana passionfruit with its larger, elongated oval yellow fruit with smooth skin. Both make great eating and are easy to grow due to their vigourous growth profile. The latter is a very vigorous and aggressive climber, very quickly smothering trees.

Elder was just one of the many plants brought by early colonists on their migration to New Zealand in the 19th century. It is quite common in the rural parts of Nelson, and around the South Island. The elder, sambucus nigra, is found naturally across almost all of Europe, western Asia and North America. Everywhere in its natural range has been steeped in myth and folklore about the supernatural, and it was commonly grown by the front door of dwellings to ward off evil spirits.

It is a deciduous small tree or shrub that does not usually grow more than about five metres, usually with many stems. The leaves are between 10cm and 30cm long and are arranged in opposite pairs. They are pinnate, with five to seven leaflets coming off in a common midrib. The large clusters of flowers appear in late November to mid December (in the Southern Hemisphere), the individual flowers are white and about 5mm in diameter.

Nasturtium officinale, or watercress is a member of the brassica, or cabbage family. Unlike may other members of this large family, watercress does not seem to be troubled by the caterpillars of the common white butterfly. Watercress is one of the oldest known leaf vegetables to be consumed by humans and has a mild peppery tangy flavour when eaten raw as a salad vegetable.

This peppery flavour completely dissapears with cooking and the plant is delicious when stir-fried with a little butter. When cooking it you need a large amount of the raw plant as it cooks down to about a quarter of the original volume. It is said to possess many health benefits and contains fairly high amounts of calcium, iron, folic acid and vitamins A and C.

Roses have been grown for many centuries and for many reasons. Today we grow roses mainly for their beauty but in the past, the rose was valued as a food and medicine as well. Rose hips, the small berry-sized, reddish seeds left on the tips of the stems are the seed pods of roses. All roses should produce hips, although the old fashioned shrub types, such as the rugosas are said to have the best tasting hips. These are also generally the largest and most abundant. The hips are usually left on the bush until after the first frost, which turns them red and slightly soft.

Rosehips have a tangy sweet flavour and can be used fresh, dried or preserved. The simplest use is to steep them for tea. Rose hip syrup, puree, jam, jelly and sauce can also be made. In World War II, the people of England gathered wild-grown rosehips and made a vitamin C syrup for children.

Lemon verbena is one of those plants that has had a name change during the last few years. It was know as Lippia citriodora: now it is known as Aloysia triphilla. It was first described under this name in the mid-18th century so this has precendence under the law of botanic nomenclature. Whatever you choose to call it, it is still worth growing for the intoxicating strong lemon fragrance of its leaves, stronger even than lemons themselves.

It was very popular in Victorian gardens as a fragrant ornamental. It was seldom used for culinary purposes and even then only as an addition to drinks. Even now it is regarded as a somewhat old-fashioned garden plant. Lemon Verbena was also used in the perfume industry and commanded a high price as it could not be produced in large quanities. Because of this, extracts from lemon grass were used as an addition and eventually, a substitute. Only in fairly recent times has the plant been used for culinary purposes, apart from flavouring beverages.