Lemon Meyer is a popular tree for both productive and ornamental values.
Not only a source of food, the garden is a place of relaxation from the world. Spring is a great time to be adding to, or planting, a home orchard.
There are a lot of summer fruiting berries and frost-sensitive varieties available in the garden centre now. Varieties such as banana, passionfruit, avocado, tamarillo and cape gooseberry all grow well in sheltered frost-free pockets of home gardens.
It is the ideal time to plant these as they will be established and be of some size by the time the cooler temperatures arrive next June.
It is also a good time to plant other fruit trees including apples, apricots, nectarines, plums, pears, peaches, plumcots, peacharines and peachcots. There are also nut trees; almonds, hazelnuts, macadamias and walnuts can all be planted now too.
Citrus perform well in mild and temperate climates and tolerate lower temperatures than the likes of bananas. Citrus includes well-known lemons, mandarins, oranges, tangelos, grapefruit, limes, lemonades, finger limes and some lesser-known fruits including limequats and tangors (a cross between a mandarin and an orange). These popular trees have both productive and ornamental values.
They can grow well in the garden or as container specimens with sweet-smelling white flowers during spring and summer and the fruits’ decorative appearance during the autumn and winter months.
Most citrus trees are subtropical or tropical and will tolerate temperatures to around -2C. Trees are fairly slow-growing with a mature specimen taking 15-20 years to reach 4-5 metres. Where the location is sheltered from wind and warmer, the trees will grow and mature faster.
Citrus trees will generally try to produce fruit from the first year but, at that stage, the tree’s ability to bring fruit to maturity is often questionable or it is at the cost of tree growth.
A good practice is to remove flowers and fruit for two to three years to allow a strong branch framework to establish. In subsequent years, if the tree is still producing larger crops than it can sustain, the removal of around a third of the crop will ensure the tree does not get into a pattern of biennial bearing. This is where the tree switches between a year of heavy fruit production and a year of minimal cropping.
To be grown successfully, most citrus trees are grafted on to a rootstock. The main rootstock used in New Zealand is Trifoliata; it is vigorous allowing the tree to grow to 4 or 5 metres over 15-20 years usually. It is also tolerant of heavy and wetter soils and creates increased frost hardiness. By trimming or growing in a pot, a citrus plant can be kept at 1.5m to 2.5m.
Meyer lemons and Tahitian limes can be successfully grown on their own roots. These are particularly suited to pots and small gardens as the plant vigour is less than that of a grafted tree of the same type, with trees reaching 1.5m if left untrimmed. They still fruit prolifically from a young age; the plants just don’t grow as big.
Citrus are gross feeders and thrive in good soil with regular feeding of a specialised citrus fertiliser. Plants which are showing yellowing of the foliage should, in addition, be given a top-up of magnesium.
Yates liquid magnesium chelate is highly recommended. It is a product that makes nutrients readily available to the plant. Where soils are lighter and sandy, an extra dose of epsom salts is recommended on a more frequent basis.
In lighter soils, particularly, an application of mulch around the base of the tree at the start of each summer will also be of benefit in conserving soil moisture and helping retain nutrients.
Pruning is only required for shaping and plants are better left untrimmed from a fruit yield perspective. Avoid any pruning between the early spring to midsummer period to reduce the risk of attack from borer beetle.
If you do prune, be sure to seal cuts with pruning paste. The tell-tale sign of a borer attack is sawdust piles on and around the plant from holes in the stems/trunk where the beetles are active.
This can be controlled with the use of No Borer Spray Injector into the holes. They can be difficult to control so prevention is better than trying to fix later.
Any shoots from the rootstock should be removed as this will reduce vigour from the tree and subsequent fruiting potential.
A long, hot summer when trees are well-watered will result in better fruit production, followed by the cooler months which promote the change in skin colour of the fruit from green to yellow. When the summer is cooler, the crop yield, size or quality tends to suffer.
When growing citrus in pots and containers, it is important to use a “premium” potting mix such as Tui Pot Power or Ican Premium Potting Mix, and fertilise monthly or bi-monthly using a specialist citrus fertiliser that is suitable for pots and containers, such as Ican Fruit Food for Pots or Yates Acticote Fruit & Citrus Tree.
The addition of saturaid re-wetting granules to citrus growing in containers is highly recommended. This product should be applied annually. It channels water to the root zone where it is needed most and promotes even water distribution, so there is less water run-off and dry spots in potting mix and soils. It makes watering, rainfall and fertilisers more effective. It can also be used in the garden, even in sandy, clay or compacted soils.
The most common problem with citrus is usually sooty mould, a black sticky substance on the leaves and stems. This is a secondary problem caused by the presence of particular scales and aphids which, while sucking the goodness from the tree, secrete a sugary substance upon which the mould grows.
The sugary substance is also attractive to ants. The good news is this is easily controlled with a spray of a suitable insecticide such as Growsafe Enspray 99, which is an organically-certified spraying oil. If you are unsure, take some sample leaves into a garden centre for advice.
For more gardening information visit www.springvalegardencentre.co.nz.
Gareth Carter is general manager of Springvale Garden Centre.
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