"Sniffer-Dog" wrote in message
...

I would also be grateful for any info from anyone who currently grows
these or knows about these tropical trees. For example how difficult
are they to grow, what type of soil is best, temperatures, lighting
and humidity etc.

http://edis.ifas.ufl.edu/MG045

Guava trees are relatively difficult to propagate by usual methods.
Consequently seed is still commonly used, although varieties do not
reproduce true to type this way. The easiest method is air layering, but it
is impractical when large numbers of plants are needed and the source of
material is limited. Veneer grafting and chip budding are successful only
when seedling rootstocks are young and vigorous (stem caliper should not
exceed that of a pencil) and the scion comes from terminal growth which is
still green and quadrangular. Leafy stem cuttings will root fairly
successfully in a mist box.

CLIMATE
Susceptibility to cold weather restricts guava growing in Florida to central
and southern coastal areas and a few warm areas in the interior. Small trees
may be killed by temperatures of 27-28°F, while older trees withstand short
periods of 25-26°F without much damage. However, if the top of trees are
frozen, they usually sprout from the ground and are back in production in
2-3 years.

PLANTING AND PRUNING
Under Florida conditions, commercial plantings are spaced 20 or 25 feet
between rows and between plants in the row. However, if provisions are made
to top and hedge as needed, distances can be shortened to 12 to 15 feet
between plants in the row. Guavas lend themselves well to pruning, which
facilitates grove management practices in close planting. Pruning hastens
flowering and fruiting by promoting vigorous flushes of new growth which
bear larger fruit.
The best time for planting trees is in early summer at the beginning of the
rainy season. Young plants can be expected to produce half a bushel of fruit
in the third year of planting, and mature trees will produce up to 8 to 10
bushels per year.


FERTILIZER
In all Florida soils, guava responds well to fertilizer applications. After
planting, fertilize each tree every 60 days with ¼ lb of a mixture
containing 8-10% nitrogen, 3-4% phosphoric acid, 8-10% potash and 4-5%
magnesium. The second year increase this to 1 lb of fertilizer per tree
every 60 days. Thereafter, use about 5 lbs of this mixture per year for each
inch of trunk diameter. For heavy bearing trees supplemental applications of
ammonium sulfate or ammonium nitrate may be desirable during periods of
heavy blooming, not exceeding 2 lbs per year for 10-year old trees.
Nutritional sprays containing zinc and manganese should be used 2 or 3 times
a year, depending on soil conditions and production. Copper should be
included in the sprays if copper-based fungicides are not used. In
calcareous soils, iron chelates specific for these soils may be needed.


PESTS
The parasitic red alga (Cephaleuros virescens) is troublesome in guavas,
particularly in some varieties under conditions of high humidity. Copper,
perhaps the best material for its control, should be sprayed as soon as the
first symptoms appear on the leaves.
Root-knot nematodes can cause severe damage to the roots of young trees in
sandy soils. Injury can be overcome to some degree by the use of
fertilizers, mulching and irrigation.

Guavas are attacked by several insect pests in Florida.

Guava whitefly (Metaleurodicus cardini) and scale insects: These can be
controlled with oil sprays containing 4-5 quarts of emulsifiable oil in 100
gal water or by a combination of oil (4 qts) plus 4 lbs of malathion 25%
wettable powder (or 2 pints of the malathion liquid, containing 5 lbs active
material per gal) in 100 gal water.

Caribbean fruit fly (Anastrepha suspensa): In recent years the larva of this
fly has been the most serious insect pest of guavas in south Florida. Larvae
hatch from eggs laid within maturing fruit and burrow through the ripe fruit
making it unsuitable for eating or processing. No satisfactory control for
the fly has been developed.

Guava moth (Argyresthia eugeniella): Although not as damaging as the
Caribbean fruit fly, the moth larvae spoil the ripe fruit by tunneling
through it. A satisfactory control has not been developed.