Feeding your trees.
Just like people, in order for trees to be healthy, they need good food and water to be their very best.
For tree in Auckland, many gardens have been stripped of topsoil when the houses were built and may have been left with poor soil conditions. Trees in South Auckland where the soil is generally lovely may struggle if the topsoil has been removed so it’s good to keep an eye on your tree’s health.
In a natural setting, the soil would forever have leaf litter, dead branches, or trees decomposing to recycle nutrients back into the soil as well as animal and bird waste to enrich the soil. As gardeners, we find this messy and untidy for the garden and so this process doesn’t always happen with a reconditioning of the soil naturally.
A lack of nutrients may manifest in your trees with stunted growth, leaves and roots, discoloration in the leaves, and even small or lack of fruit. When a tree is compromised, it will be more susceptible to damage by pests and diseases.
The easiest way to ensure your trees are getting what they need is to apply fertilizer, and the best time to do that would be in Spring. There are many options including organic, fast and slow-release, liquid, powdered, and granules. If you have sandy soils, nutrients may leach out of the soil and your trees may need feeding more often.
Fast-growing leafy trees like Michelia may need more nitrogen, as well as gross feeders like Buxus and citrus trees.
Too much nitrogen for fruit trees may result in more foliage growth and less fruit. These trees may need more potassium-rich fertilizers. Olive trees will produce more foliage and minimal fruit if there is too much nitrogen.
The roots of a tree typically reach 1.5x the width of the canopy so a light dressing around that area would be suffice. If you have a very mature tree then it is unlikely you will need to top them up as they have done well thus far. Just keep an eye on them for any deficiencies especially if there have been new garden beds or plants added to the area.
If you notice signs of deficiency in your trees then use a fast release fertilizer for a quick “pick me up”. Then apply a slow-release compound to sustain the tree through the growing period going forward.
Pots need special attention and will absolutely need to have fertilizer supplied, as the tree cannot send roots out to look for what the tree needs.
Whole tree mulch is a great soil conditioner and with leaf matter, a component of the product, the breakdown of the mulch can contribute to the available nitrogen. Good mulching as always has its advantages.