Fertilizers can be the most important "tool" for manipulating
your cycads to perform the way you want them to. First you have
to ask yourself, what am I trying to accomplish by using a particular
fertilizer? A homeowner-collector may want the healthiest plants
possible, in the easiest possible way. A lot of times people don't
have enough time to fertilize all their plants several times a
year. A nurseryman wants to grow the fastest plant possible. The
faster the finished product, the better the turnover, and the
more money you make. Companies like Disney, that are concerned
more about display purposes, want their plants to look good. With
our frosts and freezes, Cycas revoluta can get spotted and burned.
By forcing leaves out earlier, the waiting time for new leaves
can be minimized. The person who is interested in producing seeds
wants a plant to grow as fast as possible until it cones. After
that point, a female bearing seeds needs to be strong enough to
take the strain of holding seeds (usually for a year). Also, I
have found that a strong, healthy plant produces more seed than
a weak plant. As an example, I have a Ceratozamia kuesteriana
that produced 188 seeds. The next year, in a weakened state, it
produced 97 seed. After fertilizing the plant and waiting a year,
it produced 270 seeds. After experimenting for several years I
have found a way to "force" cones on cycads. The first
year I succeeded, I doubled, and tripled my seed production, depending
on the species. For the last three years, my seed production has
continued at this level, or increased on multi-headed cycads.
People are just finding out how energy oriented cycads really
are. In habitat, many cycads push leaves, at most, once a year.
Plants that are hundreds of years old, in many cases, only produce
female cones every five to eight years. Most species of cycads
can cone every year, and produce multiple leaf flushes each year,
with the proper energy. Cycas taitungensis in particular, can
produce leaves up to six times a year. I find many people using
palm fertilizer on cycads. They think because cycads look like
palms, they are closely related. Of the seed bearing plants, cycads
are about the farthest plant group away from palms. Most palm
fertilizers are low in nitrogen (with N around 7-10). To produce
a high enough energy level so that previously mentioned results
can be attained a fertilizer with a nitrogen level around 18-25
needs to be used.
After documenting leaf flushes on 150 species and coning cycles
from 25 species and correlating these results with fertilizer
applications from eight brands of fertilizer, I am pleased with
two brands. The first is Scott's Premix with Minors. It is a 24-7-8
plus minors, with 14 of the 24% being derived from a fast reacting
nitrogen. The second is Nutricote 360. It is an 18-6-8 with minors,
360 day formula. According to the distributors, the pellets are
plastic coated, and do not release more fertilizer when watering
is increased. The Premix gives a big push in the beginning, but
levels off. It lasts about three months, so it is used in cycles,
four times a year. Nutricote starts out slow, but after 6-9 weeks,
stays at a constant level for up to 10 more months, depending
on the temperature of the growing area.
In the beginning stages of growth, usually only one leaf is pushed
at a time. With each consecutive leaf flush, the number of leaves
per flush increases. In these beginning stages, it is common for
leaves to push several times a year. At a certain point, when
larger, cycads seem to change the way they grow and only flush
once per year, but many leaves per flush. As the number of leaves
per flush increases, the higher the energy level necessary to
force these new leaves out.
In the beginning stages, the Nutricote wins hands down for the
fastest, healthiest plants, When the plants get larger (around
the six leaf per flush stage), the Premix works better. As an
example, I have a group of eight Encephalartos ferox that produce
3-4 flushes per year using Premix. When I switched to Nutricote,
they flushed once during the entire year. The next year, I went
back to Premix and got 3-4 flushes on all eight plants. According
to an article written by Hannes Robbertse in The Journal of the
South African Cycad Society, cycads have an episodic growth pattern.
In most cases, I have found this to be true. Palms have more of
a continuous growth pattern. For this reason alone, your strategy
for growing cycads needs to be different from growing palms. My
Macrozamia and Stangeria seem to have a continuous growth pattern.
For these two genus, Nutricote works better.
After plants get burned in the wintertime, apply Premix at the
highest level on the label instructions. After that, wait two
weeks and cut off all the burned leaves. Usually within three
weeks, new leaves will be produced. I have used this procedure
in the middle of winter, and produced leaves on Zamia furfuracea,
Cycas revoluta, and C taitungensis. If you use this procedure
in the wintertime, and expect a frost before the leaves harden,
application of a copper based fungicide to the new leaves when
they are full size will harden them in a fraction of the normal
time.
A problem with some (usually central American) Zamias is that
they can grow too fast, and the caudex will split right down the
middle. They usually harden up, but sometimes they die. Not only
did all the Zamias react well to Nutricote, producing many flushes
per year, I have not had a single plant split in years. With premix,
I had 3 or 4 plants splitting every year. They really seem to
like the constant feed. It is important to note that some people
have found that increasing or decreasing watering schedules has
caused splitting of Zamias.
If you are looking to produce seeds, first you have to grow a
cycad to the size that it can tolerate the strain of holding seed.
Most cycads have a starch content of about 65%. This starch reserve
is somewhat depleted while holding seed. To stimulate cone production,
the plant needs to feet strong enough to hold seeds. If you fertilize
with Premix two months before the expected emergence of cones,
the plant will have this extra strength. Once you have produced
cones, switch to Nutricote, and this will keep the plant healthy
for the rest of the year. Each species has its own timing for
producing cones. If you don't know when to expect cone formation,
you may have to watch your plants the first year and chart their
timing. Either that or ask someone in your area who has dealt
with that species before.
Some species react well to fertilizer applications, some do not.
The plants that react best, at least in my collection, are Cycas
taitungensis, C revoluta, Encephalartos arenarius, and E. ferox.
You will see the best results of the use of Premix with these
species. Dioon mejiae does not react well to fertilizer. This
species seems to wait until about June or July when the weather
heats up before leaves are produced. For plants like this, you
may as well use Nutricote because it's easier.
A homeowner may not have enough time to fertilize often. In many
cases, a homeowner may want nice looking plants, but may not care
how fast the plants grow. In this case, they can use Nutricote.
One application in the spring and forget about fertilizing for
the rest of the year.
Fertilizers can be the most important tool a grower can use. Keep
in mind that over-use or over application of fertilizers can kill
your plants. As long as the pH of your soil does not incapacitate
your fertilizer, the proper use of it will show you great results.
Cycads are thought to be very slow growing plants. In habitat,
these plants are relying on their coralloid root systems, which
produce very low levels of nitrogen. If you use a high nitrogen
fertilizer that has a release pattern similar to the growth pattern
of a particular species, growth can be optimized. With the proper
use of fertilizers, cycads may no longer need to be known as "slow-growing"
plants.
Author's note:
This article is mainly to explain how cycads react to certain fertilizer applications. It is not important to use these particular products, but a produce that has the same basic analysis. Premix in particular, has been discontinued. Also, certain products may not be available in different parts of the world. For those people in Florida who may be interested, I have had a wholesale fertilizer company produce a fertilizer to my exact specifications. It has been tested by myself and and others in different parts of the US, and it has been working very well. I have improved it over the old mix. I have it available now in 50 pound bags.
