Lemon and mandarin trees beside the driveway

We are never going to suffer from scurvy here. We have fresh citrus fruit in the garden twelve months of the year and our lunches are accompanied these days by a glass of fresh squeezed orange juice. It takes an average of six oranges each to get a full glass of pure juice.

Of all the fruit trees we grow, the citrus is probably the crop we take most for granted but would miss the most if we were to be deprived. Were it not for Mark’s parents, we would not be so blessed. As far as we can make out, they must have started planting grafted citrus back in the 1940s and 50s – a time when few people realised we could successfully grow any citrus other than lemons in our climate. Mark can remember some of them being mature when he was a young child. We did a quick count – we think we have about 20 productive trees dotted around the garden, mostly oranges, and that does not include the new plants we have waiting to be planted out.

The earliest trees planted here, a generation or maybe two earlier than Felix and Mimosa, were seedlings which grew too large and were erratic at best with fruiting. The breakthrough came with trifoliata root stock which is much more adaptable to our climate and is also a dwarfing stock. Most of our mature citrus trees are now in the 3 to 4 metre height range.

Oranges: When it comes to oranges, one variety stands head and shoulders above all others for us. The Lue Gim Gong on trifoliata stock is the breakthrough variety in this climate. When all the other oranges have finished fruiting, we can continue picking the Lue Gim Gong and it keeps us going twelve months of the year. When the fruits hang on to their second season, the skins turn a deeper orange and the fruit gets even sweeter and juicier. It is a form of the Valencia orange and dates back to Florida in 1876 where it was recognised as a breakthrough because it is sweet and more frost tolerant than other Valencias. If you can only grow one orange, our pick is definitely the Lue Gim Gong and it is still available for sale (try Google).

The distinctive navel orange - good eating

Because we can grow more than just one variety, we also have the Jaffa (excellent crop and flavour and most attractive on the tree as well as a long season) and a range of navel oranges. It appears that all navel oranges descend from the one specimen but some have sported over the years to give variations. Of them all (and I think we have tried most of them) the Leng Navel has the best flavour. It is hard to beat a good, tree-ripened navel orange for eating but the downside is that their season is comparatively short and they don’t hold on the tree. If you are not around to pick them, they fall off and rot. We have a blood orange waiting to be planted out. The flavour is good but the red colouring seems to be dependent on a hotter summer than we can give.

Lemons: Most New Zealanders grow a lemon tree except for people who live in the coldest areas. The Meyer is the most common because it is most tolerant of a range of conditions but it is not a true lemon, being thought to be a natural cross between an orange and a lemon. We planted a new lemon tree several years ago but we have lost the label. It is certainly not Meyer – it may be a Lisbon. We were very disappointed in it for the first couple of years because the fruit was thick skinned and unappealing but it has settled in well and gives us plenty of fresh lemons throughout much of the year. This specimen does require regular copper spraying to prevent leaf blights.

The Tahitian lime - a favoured crop for kitchen use

Limes: I prefer the old Tahitian lime we have which is under two metres high and a little wider. We tend to leave the fruit to turn yellow and use them like juicy little lemons. The fruiting season is not as long but the volume of fruit is excellent. The younger leaves are also aromatic for flavouring Asian dishes. I use the ripe yellow limes to salt for use in Middle Eastern dishes. They are a more convenient size to put in jars and have a thinner skin. If you are warm enough to grow a Tahitian lime, it is well worth its place in the garden. Preserved Lemons recipe.

Grapefruit: We have a couple of trees which fruit well but they are not in a convenient location so we tend to ignore them and the crop goes to waste. Proper grapefruit do not do well in New Zealand, apparently. It appears that they need a hotter climate than most citrus. What does grow here is the New Zealand grapefruit or Poorman Orange which was apparently introduced by Sir George Grey to Kawau Island. It came from Australia and is thought to be a natural hybrid, probably between a pomelo and a mandarin. Alternatively the Wheeny grapefruit is grown here (we have one) and it has a thin skin and a good flavour though it is not as hardy as the Poorman. My late mother in law was a splendid jam and marmalade maker and her advice was that neither the Wheeny nor the Poorman has sufficient pectin to set marmalade easily so it is necessary to add lemon juice.

Mandarins: These are particularly decorative and ideal for families with children, especially when they are the easy peel varieties. Besides plucking fruit as we pass, much of the crop sits on the trees looking attractive here because in the end we would rather eat oranges. Silverhill, a named form of Satsuma, is the best producer for us. Our Clementine died which was a pity. It had a better flavour but because it is not as easy to peel, it is never going to be as attractive to children. Added to that, it has many seeds and seedless citrus is preferable for eating.

Tangelos fruit well and are easy to peel, though messy, and delicious when you get good ones. It is thought that the tangelo is a hybrid between a mandarin and a pomelo (also known as a shaddock). They are not a replacement for oranges but they are a good addition where space allows. They have an unfortunate tendency to produce some dry fruit for us but we have never worked out why – we suspect it is varietal rather than conditions.

A mature Jaffa orange grown as a lawn specimen

Growing conditions and general maintenance:
When choosing a site for citrus trees, give them as much sun, warmth and air movement as you can, along with good drainage. We have some as lawn specimens and they appreciate the open conditions. However, they are now so old that there is a clear space under the canopy which stops grass competition. On young specimens, it would pay to keep the trunk clear and not to mow within half a metre or so. We do not go in for the urban fashion of growing citrus in containers so can not give specific advice on that practice beyond the generic techniques for growing plants in containers.

In the world of fruit trees, our citrus are remarkably easy care. Common advice is that they need plenty of feeding but we rarely bother. Years go by between feeds. That said, yellow foliage is usually a sign of nitrogen deficiency so if you have a sickly yellow citrus, give it some fertiliser or compost and make sure that whatever you use is rich in nitrogen. With regular rains twelve months of the year, we never water. It is often said that citrus need plenty of water to keep the fruit juicy but I have seen them growing extensively in Spain and Italy where conditions are bone dry and hard and I can’t imagine that watering was particularly consistent or thorough.

Control against the borer larvae

We do not regularly prune the trees. All we do is take out the dead wood or any wayward branches as required. Borer is one of the biggest problems but not so big that it threatens the entire tree. If you are more thorough, you can inspect the trunks and branches and kill out the borer larvae by injecting holes with oil, insecticide, kerosene or other variants. Look for the tell tale signs of holes with a ring of sawdust beneath. Spraying CRC down the hole using the fine nozzle works a treat, suffocating the grub, though Mark is of the view that flyspray with the same fine tube would be better. The borer can kill a whole branch which is why we need to prune out dead wood from time to time.

Neither do we worry too much about spraying the trees (except for the above mentioned lemon). They certainly do not undergo any regular spray programme. What little is done here is strictly on an as-required basis. Leaf roller caterpillars can be a problem because if they damage the skin of the fruit, it is enough to make the fruit drop off.

Sometimes we get an attack of brown rot which gives, surprise surprise, brown rotten patches on the fruit and causes extensive defoliation. Mark is out with the copper spray on the very next fine day when we notice this. In theory he does an autumn copper spraying round of all the citrus trees but in practice this can be hit and miss. We have enough trees here to ensure that if one or two have a bad year, we don’t run short of fruit. The use of trifoliata root stock is a major factor in enabling us to continue with such a laissez faire approach because it shows excellent resistance to many common problems.

All of which brings us to the thorny issue of climatic range. We can’t say, is the answer. We garden on volcanic loam about five kilometres from the coast. The disturbed westerly air patterns mean that such frosts as we get are only mild (a degree or two) and we never get very cold. On the other hand, we never get particularly hot either and we have high sunshine hours, high humidity and high rainfall twelve months of the year. The Meyer Lemon is the hardiest of these citrus. If you are in doubt, check whether it is growing nearby. If it is, then you could start experimenting with other options but don’t get too carried away until you can see some success. Coastal areas are always milder. While citrus are happy in places with hot summers, if the corollary is a very cold winter with heavy frosts and maybe snow (a continental climate), it will generally be too cold for them in winter.

Trifoliata coming away below the graft - our preferred root stock

In summary:

• Source trees budded on to dwarfing root stock or learn how to bud your own plants. Our experience is that trifoliata stock is successful. This root stock keeps the trees smaller and gives greater hardiness and disease resistance in less than perfect conditions. You can grow your own rootstock from cutting if you find a tree which is sending shoots from below the graft as shown in the photograph. You then need to bud or graft onto the rootstock. For general instructions on budding, check out our Outdoor Classrooms:
Autumn chip budding
T budding

• Citrus can be a decorative addition to the garden as well as being productive (and the scent at flowering time is divine). If you have space for several trees, you don’t have to be so particular on spray and maintenance programmes.

• Healthy, established trees in good conditions do not succumb as readily to pests and diseases.

• Lue Gim Gong on trifoliata stock is our single best orange variety here and guarantees fresh fruit twelve months of the year.

• In our conditions, the citrus range are probably the most rewarding and easy care tree crop we grow. You can go to a great deal more trouble and effort if you want, but you can get away with very little.

Lue Gim Gong as a lawn specimen - our top performing orange