Citrus trees are easy to grow and perfectly suited to the Northland climate.
Planting Citrus can be done most times during the year,choose a warm, sheltered, sunny site, they don’t like to be exposed to a prevailing wind or even a persistent draught so use a shed, fence or hedge to give the tree the protection it needs. Citrus trees have a lot of surface roots so leave the area around the roots clear of other plants so it will not have to compete for food so because of this don’t dig too deeply close to the tree.
Drainage is very important, heavy soils especially clay will waterlog the roots in the winter and dry them out in the summer.
Prepare the hole by digging it a little deeper than the length of the bag and half as wide, this will make filling the hole easier. Mix a good couple of handfuls of blood and bone to the bottom of the hole and lightly mix it in to the soil, use the soil level that is in the bag as a planting depth guide –this is the level that you plant to, planting it deeper than that will encourage the trunk to rot.
After planting choose only the topsoil to return around the tree if you are a little short of soil mix the top soil with a little compost, leave out the subsoil, this will often be harder and heavier and will have no benefit. Tamp the soil down well and give it its first watering. If you are planting more than one tree then plant at least 3 meters apart.
Care –Fertilising your citrus trees is necessary they need a balanced food, often a poor crop will be due to insufficient feeding. Use a prepared Citrus fertiliser twice a year, fertilising in August and the again around February, always water the fertiliser in.
Citrus trees will sometimes need an extra boost during the season to balance a magnesium deficiency – this is deficiency is often evident with a yellowing of the leaves. Epsom salts are used to correct this problem. You can use mulch around citrus trees – grass clippings, leaf mould and compost are great for this as they will add nutrients to the soil and will help to conserve water in the summer. Pull back the mulch when feeding with fertiliser. Make sure you don’t heap the mulch around the trunk as this creates moist conditions that are ideal for bark diseases.
Pruning citrus trees is easy their requirements are few and not to complicated. Early pruning is usually done to improve the shape and pruning as the tree ages is for health and fruit production. Citrus wood is softwood make sure all cuts or damaged to the wood is cleaned and sealed with pruning paste. Open wounds will very quickly be infected by borer.
Prune to keep the tree open to the sunlight, this is done by removing any branches that over crowed the middle.
Remove any damaged or badly infected branches and reduce by half any very long branches.
As the tree grows ensure there is up to a meter clear from the ground to the start of the branches, this will protect the branches from damage by the mower.
Remove any shoots that grow from the trunk below the graft these are commonly called water shoots and serve no value. Remove when they are small will avoid larger cuts later.
Keep an eye out for branches that look like they are going to cross over the centre of the tree. Branches that cross over each other will rub together in the wind and cause damage to the bark.
All citrus need water and lots of it especially during the dry summer months;they are after all a juicy fruitland a shortage of water will cause the fruit to be small and shrunken. Citrus trees that are grown as specimen tress in the lawn will compete with the grass for moisture in the dry weather so keep up the watering. You can use mulch around citrus trees to help conserve water in the summer, grass clippings, leaf mould and compost are all good for mulching and you can pull back the mulch when you need to fertilise. Make sure you don’t heap the mulch around the trunk as this creates moist conditions that are ideal for collar rot. Keep the mulch at least 10-15cm away from the trunk.
Bugs and diseases do affect citrus trees, but in conjunction with a good feeding and watering programme spraying can be kept to a minimum. The table below outlines a good basic spray program that you can use, the two sprays are considered to be environmentally friendly.
WHEN WHAT CONTROL
November - after petal fall - this is when the petal have all fallen off and the fruit has formed. Copper Oxychloride Verrucosis, brown rot and thrips
December - after main flowering Copper Oxychloride Verrucosis, brown rot and thrips February - Conqueror oil Scale - make sure you get under the leaves as well.
May - Copper Oxychloride Verrucosis, brown rot and thrips
June - Copper Oxychloride Verrucosis, brown rot and thrips