Page 112 - Tài liệu cây cảnh Bonsai4me Bonsai Basics

species (particularly when in training) during the Spring, the higher proportion

of Nitrogen encourages stronger leaf and shoot growth and can encourage faster
growth. It should not however be fed throughout the growing season as this
would eventually result in too lush green growth with long internodes.
A fertiliser low in Nitrogen is very useful when applied to bonsai from late-
Summer through to dormancy. The relatively high Phosphorous and Potassium
content helps to strengthen the years growth and the root system before the cold
of Winter. It also increases bud production for the following year. Top growth
that would otherwise succumb to the first frosts in Autumn is slowed. Ultimately
a fertiliser that is rated as 0:10:10 and contains no nitrogen is preferred but can
be hard to obtain and is relatively expensive. A suitable alternative is to use a
low-nitrogen fertiliser (12.5:25:25) that is diluted by half.
Fertilising Lime-Hating/Ericaceous Plants

Lime-hating plants such as Enkianthus, Azaleas (Rhododendrons) and
Stewartia require regular replacement feeds of specially formulated fertilisers
which ensure that their soil pH remains acidic, ericaceous fertilisers also contain
higher levels of chelated iron which is required by lime-hating species to offset
chlorosis.
Many Pine species and Juniper species also benefit from monthly 'acid'
feeds.
Suitable fertilisers include Miracid or any other fertiliser that is indicated as
being specifically for ericaceous or lime-hating plants.
Solid Fertilisers

Japanese bonsai growers traditionally used solid fertilisers such as small
cakes of fish-meal or rape-seed that are placed on top of the surface of the soil
and these slowly release nutrients every time the tree is watered. The primary
advantage of solid fertilisers is that they continually supply the tree with small
amounts of nutrients and only require replacing every two to three months so are
less time-consuming to apply.
There are now several solid/slow-release fertilizer-brands on the market
including Green Dream and Biosorb, both of which are excellent for outdoor
bonsai (they tend to leave an odour which makes their use indoors less
attractive!)
Overfeeding

If the nitrogen content of the bonsai soil becomes too high it will burn the
roots. Always follow the mixing and application rates described on the fertiliser
packaging, never mix a higher concentration than is described and do not feed
more frequently than is described. Overfeeding can result in less growth NOT