Lemon trees are a very important small tree in our home gardens. They should look nice all year round and provide us with good quality fruit.
Lemons suffer in summer time from lack of water. This has three major effects on the tree. Firstly the fruit will be dry and pithy, secondly the leaves will turn yellow and fall off, thirdly it will not grow well and make new flower buds for the following year and there will not be any lemons.
Lemons are surface rooted. Take a quick look under the tree and scrape away some soil and you will see the roots. They will be a light yellowy colour. It does not take much to dry them out. The best and only fix for this is to mulch the soil with good quality compost. Then make sure the soil and compost is kept moist with regular watering. Reapply the compost at regular intervals.
If the leaves are turning yellow and the tree looks weak apply about 500 grams of citrus fertiliser every two months to the soil surface and water it in. Do not dig it in as you will damage the roots.
The other disease you may find on the fruits is a warty surface which is called Citrus verrucosus. This is controlled by a copper based spray and winter spraying of all seasons spraying oil. If the infection is bad remove the fruit and let the tree start again but make sure you use these two sprays.
To keep those unruly grape vines from climbing everywhere in summer a
little summer pruning is necessary. Completely correctly it will not affect the
size or quality of the grapes.
Using a clean pair of secateurs look at each shoot on the vine. Count
three leaves from the bunch of grapes towards the growing tip and cut off the
end of the shoot leaving the bunch of grapes and three leaves.
Later in summer you may need to do this again follow the same rules OR
remove all the new shoots that grew after your last summer pruning leaving only one leaf on that
new shoot.
Apples flower and fruit on spurs. Spurs are short multi branching stems along the main branches and pruning should be undertaken to develop, enhance or replace these spurs. There are two main structures of apple trees. Vase shaped where upright branches are trained in a V formation and spurs are developed along these upright branches. Espalier and centre leader trees both have a vertical trunk and the side branches are trained and tied down to grow horizontally to produce fruiting spurs. Also the lower in the tree spurs are produced the easier it is to tend the fruit and to pick it Knowing the style of tree being pruned is important to enable fruiting spurs to be encouraged where required and to remove unwanted branches. In all pruning start by examining the structure of the tree and identify any new branches that should be kept to improve the style and structure of the tree. Tie these into place. Once the structure is sorted then the removal of unwanted branches can begin. Shorten them back to at least one third of their length. When pruning branchlets on a fruiting spur cut back to about one third so that the spur will continue to develop. On older spurs look at the possibility of removing some very old wood which can be replaced by new young growth. Remove all the unwanted material from the tree. If this material is diseased burn it or send it away in the green recycling bin. Gardeners should be able to recognized the difference between flowering buds on an apple tree and non flowering buds. Flowering buds are fatter and rounder and are usually at the end of a short spur. Keep as many of the flowering buds as possible. Always use sharp secateurs and for larger branches a sharp saw.
A 500 year old grapevine that was cut back by vandalism has sent out some new shoots. When cut back it was not expected to live. This vine is a great grandparent of the popular variety Gruner Veltliner a white grape which is a particularly good food wine. It is being experimented with in NZ currently as a grape producer for wine production.
The Tamarillo is a native of the Andrean Region of Peru South America and was introduced to New Zealand from plants grown in India in 1891. It is a member of the Tomato family producing many large egg shaped fruits ready to harvest in autumn and winter.
Often called the Tree Tomato in NZ it is quite popular as a fresh fruit. Two varieties are grown, red fruited and yellow fruited. Flavour can be quite tart to some people but for others it is a fresh tasting highly flavoured fruit when eaten raw. It can be used as a stewed fruit as a filling or even poached and decorated as a desert. The yellow varieties are milder in flavour.
It is a subtropical plant and tolerates only very light frosts requiring warmer climates or special microclimates. It is grown commercially in the northern parts of New Zealand.
Growing is quite easy as it copes with a variety of soil types provided it does not get wet feet. The large leaves are easily damaged by wind.
Once established it grows quite quickly with thick soft branches. Good training of a strong branch system is important to support the leaves and weight of fruit. They flower on fruit on new seasons growth which means pruning in early to late spring to get the longest growing season possible.
Harvest fruit from late autumn through to early spring. Fruit ripening will depend on local conditions and the time pruning took place. Early pruning in spring will give an early crop with later pruning giving a later crop.
Common pests and diseases include whitefly, aphids, looper caterpillar and powdery mildew.
Tamarillos are great talking points in the garden their large leaves make an impressive statement. While the flowers are small and sometimes insignificant the fruit makes a fine display and a great talking point.
Citrus fruit are often described as hard to grow and they need to be grown in sheltered locations. But really it’s just common sense. Some citrus are much hardier than others and can be grown in less sheltered areas while the more tender ones should be positioned facing north where they capture a lot os sun and can be easily watered.
The another requirement for Citrus is that they need a free draining soil to prevent the fine feeding roots from rotting. Citrus roots not only have those fine feeding roots in the top layer, but also have quite long anchor roots which grow down into the subsoil. Positioning them away from your underground services is a consideration.
Another major consideration to grow successful Citrus is to place them where maximum sun is found because this will help fruit mature at a much faster rate than growing them in partial shade.
Another key is copious quantities of water placed over those fine feeding foots during those hot dry summer months, which if not done the plant will tend to roll its leaves and produce a reduced yield of fruit. To prolong the effect of moisture, mulch could be applied to a depth of 100mm, using such material as compost, organic mix, or similar. Its very important that you never disturb those fine feeding roots by hoeing or digging as this will have the effect of yellowing the leaves and general decline of the citrus tree. Apply mulch twice a year.
As for pest and diseases there are a few that have to be kept under control, making sure that they are sprayed before they become too bad. Aphids tend to effect the growing tips and this can stunt growth, but they are easily controlled by spraying with any insecticide or use an organic method like Pyrethrum, but spray them early.
Scale is also a problem on citrus appearing both on the undersides of leaves and along the stems. If the problem gets too bad black sooty mould grows on the honeydew excreta which can clog up the all important breathing holes on the tree. The scale insect sucks out all the moisture and nutrients from the plant effectively killing it. This has the effect of yellowing leaves, which drop off and general lack of growth is seen.
Affecting some Citrus is Verucosis which distorts the fruit with scabbing lesions appear on them. They should be sprayed when they appear usually from October to June with a copper-based spray.
Another major pest that affects the leaves and fruit of the citrus is the Red Mite which is a microscopic insect that tends to suck the juices out of leaves making the leaves appear light or even translucent as well as discolouring the fruit.
Most citrus are grafted onto trifoliata root stock which is more disease resistant and tends to produce a more compact tree which matures more quickly and often produces more fruit. Sometimes the rootstock grows away from a single bud below the graft union. Cut these off carefully with a knife very close to the main stem.
Citrus are heavy feeders requiring large applications of fertiliser at least twice a year in October and February of mainly Superphosphate that helps root development and Sulphate of Potash which helps fruit set and improves colour. The addition of slow release Nitrogen through Blood and Bone also will help in the making of constant healthy green growth.
Most citrus require minimal pruning, but quick growing plants like mandarins may require thinning out occasionally while others such as lemons require keeping in shape by cutting back long stems. This is usually done after harvesting the fruit as all citrus fruit on one-year-old wood.
There are many types of citrus. Often the choice of what citrus to grow is determined where you live and how much shelter and protection you have around your section. Most people choose lemons or grapefruit, but often oranges and mandarin can be grown.
Lemons - Meyer lemons are the hardiest of the citrus group, being compact, the fruit is medium sized, smooth skinned and matures in winter/spring, but lemons can usually be picked most of the year. Meyer lemons can be grown by cuttings and grow on their own roots.
Other lemons are Lisbon, Eureka, Genoa and Villa Franca, all being juicy, thinned skinned.
Grapefruit - Morrison Seedless is the most well known variety but one called Golden Special is also seedless, thinned skinned and generally grows into a nice shaped bush. The flesh is orange and it ripens from July to October. Because of its vigorous growth it is wise only to shape the bush on a regular basis.
Mandarin - has heavy crops of sweet fruit on compact bushes. It needs regular feeding and plenty of moisture. Clementine is probably the best all round variety with medium sized fruit of good flavour. Ripens late July to September.
Orange - these are the least hardy of the citrus fruits and requires a warm sheltered area and are often grown in containers in Christchurch. Like most citrus they require a good composted soil and plenty of moisture. The main varieties grown in New Zealand is Carters or Washington Navel which ripens from early August to September and Best Seedless which is a mid season variety ripening September to November while Harwood Late ripens in November to December.
Tangelo - these are a hybrid cross between Mandarin and Grapefruit and they are intermediate in character between the two. Seminole is the major variety grown in New Zealand and bears heavy crops of large, attractive, thin-skinned, flavoured fruit. They ripen in September and hold on until December.
Ugli Fruit - this is a hybrid between a grapefruit and a mandarin. It is a large thick-skinned pale orange fruit, ripening in August through to September.
Kumquat - these trees are small, dense and highly ornamental making ideal tub and container plants. They are relatively hardy and produce heavy crops of golden fruit which are eaten whole, skin and all.
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