Why haven't my 7 year old decidious trees grown for the last 2 years?
The trees are planted in light red basalt soils surrounding the homestead. The lawns and trees are bore watered regularly over summer. Species incl Silver Elm, Golden Ash, Claret Ash, White Cedar, Flowering Plum and Flowering Cherry. The trees have made little growth over the last two seasons and may need a 'feeding' programme to get them moving. Can you please advise what to give them and when...also how much. The trunks are about 100 mm diameter.
It sounds like the trees you have planted have done extremely well over the last 7 years to be now 5 metre tall. They obviously like the soil they are growing in. A 'feeding programme' would be a good idea. You can either choose an organic fertiliser, inorganic fertiliser or perhaps a combination of the two, we recommend Yates Dynamic Lifter Soil Improver & Plant Fertiliser. Spring would be the time to apply a fertiliser. The soils will be warming up at this stage and the trees putting on new growth. Organic fertilisers such as Dynamic Lifter Plus Organic Plant Food would be suitable for all of the trees you have growing. Acticote is a slow release fertilise which can be applied in spring and again in autumn. The fertiliser will be released over that period of time to ensure the trees received all the nutrients they need to put on new growth and maintain strong growth. Continue to give your trees a deep watering on a regular basis during the summer months and I am sure they will reward you by putting on lush new growth. Enjoy.
Why do we need to fertilise our garden plants?
For a start, unless you are growing plants in their natural habitat and returning all waste matter to the soil, the soil will need to be fertilised to replace lost nutrients.
As well, those garden plants that originate in soils with higher nutrient content they will need to be fertilised to grow happily.
Another reason for fertilising is that, in time, established plants use up all the goodness in the surrounding soil.
And some plants, such as fruit trees, vegetables and roses, have been bred to be super productive and need extra. Lawns are other good examples. Every time the lawn is mowed and the clippings removed, the plants have to begin re-growing their leaves again.
It is important to be aware that fertilisers are not 'food' for plants plants manufacture their own sugars from the sun but are necessary to enable plants to function effectively. However, generally, the term 'plant food' is commonly used when referring to fertilisers.
Elements Essential for Plant Growth
Carbon, oxygen and hydrogen can be obtained from the air and water but all other elements are dissolved in water and taken up by the plant's roots or, to a limited extent, by its leaves.
1. Major Elements
Nitrogen is an essential part of the proteins in plant cells. It is most important for leaf growth and is a necessary part of the green pigment chlorophyll.
Phosphorus is imprtant in cell formation so is most needed by the growing parts of the plant. Phosphorus promotes the development of seedlings, root growth, flowering and formation of fruits and seeds.
Potassium assists in photosynthesis and is helpful to the plant's 'food factory'. It assists the plant's overall strength, water uptake and disease resistance, and improves the quality of flowers, fruits and seeds.
2. Minor Elements
Calcium forms the cell wall structure. It is available in lime, superphosphate and gypsum but is quickly leached out by heavy rain. Watch out for blossom end rot (sunken areas on the base) on fruits, especially tomatoes. This is caused by lack of calcium or by poor uptake of calcium which may be a result of unreliable watering.
Sulphur forms part of plant protein. Deficiency is relatively rare because sulphur is found in most plant foods.
Magnesium is important in photosynthesis because it is present in chlorophyll. New leaves have first call on this nutrient and, because magnesium moves very readily through the plant's system, deficiency is most often evident as yellowing of the older leaves.
A magnesium boost is supplied by an application of Epsom Salts dissolved in water.
Iron, Manganese, Zinc, Copper, Boron, Molybdenum.
Trace elements are essential to plant growth but are only needed in minute quantities. It is important to remember that the symptoms of excessive application may be as severe as the symptoms of deficiencies in other words, use sparingly!
Answered: 6 Jul, 2014