The publications in this collection do
not reflect current scientific knowledge
or recommendations. These texts
represent the historic publishing
record of the Institute for Food and
Agricultural Sciences and should be
used only to trace the historic work of
the Institute and its staff. Current IFAS
research may be found on the
Electronic Data Information Source
site maintained by the Florida
Cooperative Extension Service.
Copyright 2005, Board of Trustees, University
University of Florida
SUB-TROPICAL EXPERIMENT STATION
Homestead, Florida LIBRARY
FROM THE LIBRARY
2- GROWING GUAVAS IN FLORIDA OF
Geo. D. Ruehle A I
Interest is increasing steadily in growing the common guava (PsjAdm guajavaL
in Florida. Several rather large commercial acreages and a number oA s ler
plantings are in bearing in southern Florida and additioNal acreage is *f6g pla ed
at present. Manufactured guava products are being produebi1T a commercial way n
increasing quantities. It seems probable that the demand rf 'suh( oducts wil
continue to increase steadily, provided they are advertised t~ ign Q r.ke so
as to keep pace with expanded production.
The guava ranks far above many of Florida's better known fruits in nutritive value,
and its wider use in the diet is justified from this standpoint.
An increasing number of people are learning to use and enjoy the better types of
guava, either eating them as fresh fruit or cooked or preserved in various ways.
Methods of preparing guavas are described in Florida Agricultural Extension Bulle-
tin 70, "The Goodly Guava."
Practically all of the commercial plantings of guava in Florida are of seedling.
tree-s. The fruit from seedling guavas grown from unselected seed may exhibit a wide
variation in appearance, size, flavor, acidity, texture and color. The shape may be
pyriform, ovate or globose and weights vary from less than 2 ounces to more than 1
pound. Skin color ranges from light green to bright yellow and in some types a
faint pinkish blush occurs on the exposed side. The flesh color may be white, sal-
mon, pink or carmine. Seedling fruits vary from thin fleshed with a large seed cav-
ity to thick fleshed with few seeds, and in flavor, from sweet to highly acid. Some
are high in pectin and low in acid; others are high in both pectin and acid and are
superior for jelly making. Ascorbic acid content varies from below 50 to more than
00 milligrams per 100 grams of fruit pulp. Some guavas have a strong objectionable
odor; others are very mild.
Local descriptive names, such as lemon guava, pear guava, or apple guava, are in use
for some of the common types. Quality of the fruit, however, cannot be determined
from the color, shape or size of the fruit. Several unnamed varieties are grown in
commercial plantings. Some processors have types of guava which they prefer for the
manufacturing of jelly or other products and propagate these by planting seed from
selected fruits or by grafting.
Seedling guavas cannot be relied upon to produce fruit identical with that from the
parent tree. Choice varieties can only be increased by some vegetative means of
At present, only a few named horticultural varieties of guava exist and trees of
these are not yet offered for sale in quantity by nurserymen. The Red Indian and
Ruby are red fleshed, sweet, large fruited, dessert-type guavas producing good crops
of fruit of high quality. The Supreme produces heavy crops of thick-walled, sub-
acid, white-fleshed fruit of good quality suitable for preserving or eating fresh.
All three of these new varieties produce fruit high in ascorbic acid content and are
excellent types for planting in home gardens or for sale as fresh fruit. The Redland
produces white-fleshed fruit weighing up to 1 pound, which is inferior in quality and
low in ascorbic acid content. It is no longer recommended unless one desires an es-
pecially mild flavored guava. No doubt there are many excellent seedlings in Florida
Mimeographed Report No. 11I
which merit propagation as horticultural varieties but which have not been brought
Guavas are commonly propagated by seed, which should be planted as soon as possible
after their removal from the fruit. They should be sown in flats or bulb pans filled
with a sandy loam and covered to a depth of about 1/4 inch. If the soil was not pre-
viously sterilized, it is advisable to treat the seed with red copper oxide before
planting and to spray the young seedlings and soil with Cuprocide (1 oz. to 3 gals.
of water) to prevent damping off. After the true leaves appear, the seedlings should
be transferred to individual containers where they should be grown until they are
large enough to set in the field, since they are not easily transplanted from the
The guava is rather difficult to propagate by the usual methods employed with other
fruits. Both shield and patch budding or side-veneer grafting are successful on
young stock plants but it is difficult to obtain a high percentage to live. Shield
budding is most successful if the buds are inserted in young stocks as soon as the
bark is thick enough to receive the bud, Budding is best done during the winter and
early spring. Buds should be cut 1 to 1 1/2 inches long from wood from which the
green color has just disappeared from the bark. When older stocks are used, shield
buds frequently fail to sprout readily.
Side veneer grafts on young stocks, using scion wood of the same diameter as the
stock, are somewhat more difficult to make live than shield buds. The very hard
nature of guava wood makes it difficult to make the straight cuts necessary for
matching stock and scion perfectly. However, if the union is successfully made, the
graft develops into a tree faster than the shield bud.
Patch buds may be made on stocks an inch or more in diameter but the buds usually
sprout slowly and this method has little to recommend it. Stocks of this size are
readily topworked by use of the crown bark graft similar to the method used in top-
working citrus, except that it is advisable to protect the scions from drying out.
This is accomplished by tying a paper collar around the stub and scion and filling
this with moistened peat moss, sphagmum, or a mixture of these materials with sand in
addition to coating all cut surfaces with grafting wax. By taking similar precautions
against drying out of the scions, large seedling trees may be topworked in the grove
either by cleft or crown bark grafting. Usually, however, the guava persists in
suckering below the graft union following the topworking of old trees.
If guavas are grown where there is danger of the top freezing back to the ground, it
is desirable to have the roots of the same variety as the top, so that the original
variety will be retained when suckers arise. The guava can be air-layered in the
manner employed for propagating the lychee. The principle involved is to girdle the
stem and then enclose t4h portion in a "marcottage" box filled with moss or other
suitable rooting medium. The latter is kept moistened by watering if necessary un-
til roots develop from above the girdled area. The stem is then severed below the
box and potted without removing the rooting medium.
Another method of making a limited number of plants, is to sever roots 2 to 3 feet
away from the trunk with a spade or mattock, and sprouts will grow from the portion
cut off which may be transplanted later.
Root cuttings 5 to 8 inches long cut from roots 1/4 to 1/2 inch in diameter planted
horizontally to a depth of 3 or 4 inches in nurseries-or cutting beds will often
root with fair success, if the soil is kept moist but not too wet. Comparatively
little success has attended attempts to root stem cuttings, although the use of hor-
mones in connection with this method has not been thoroughly investigated.
The guava can be grown successfully on a wide range of soils. It thrives on well-
drained, loamy and muck soils, but will grow vigorously on light sands, shallow
limestone and marl soils if properly fertilized.
Experimental data are not available concerning planting distances for guavas grown
on the various soil types. Indications are that in commercial plantings where heavy
fertilization is to be practiced, the trees should not be planted closer than 20
feet in rows 20 to 25 feet apart.
The land on which young guava trees are to be planted should be cleared and prepared
some months ahead of planting. In deep soils the land should be plowed and disked;
in limerock soils it should be well scarified and grooved or plowed out where the
tree rows are to be located. On newly cleared sandy soils with a strongly acid re-
action, it is desirable to make a general application of dolomite at 500 to 2000
pounds per acre (the amount depending upon the degree of acidity) broadcast and
disked in just before or just after the trees are planted. On newly scarified lime-
stone soil n application of superphosphate at 500 to 1000 pounds per acre similarly
broadcast is desirable.
Guava trees are usually planted to best advantage during late spring just ahead of
the rainy season. A planting hole must be prepared large enough to easily accommodate
the root system. Before placing the tree, the soil in the bottom of the hole is
commonly mixed with some topsoil fortified with a small amount of well-rotted compost
or with a natural organic fertilizer such as dried sheep manure or steamed bonemeal.
The tree should be placed so that the roots are no deeper than they were in the nur-
sery or plant container, the soil should be well packed and the tree watered liber-
ally as soon as planted to avoid air pockets. When the hole is completely filled, a
basin is formed around the tree for water. After the trees are planted and watered,
it is advisable to mulch the basin heavily with grass and weeds or sawdust to prevent
drying out and heating of the soil about the new roots.
Fertilizing Ron-bearing Trees
Guava trees may be grown very rapidly by the use of nutritional sprays combined with
frequent and liberal applications of fertilizer.
Applications to the foliage every 3 or 4 months of a nutritional spray containing
copper and zinc will improve the growth and. vigor of the young seedlings growing in
plant containers. The following spray formula is suggested:
Cuprocide 1 1/2 lbs. (or its equivalent in some other neutral copper)
Zinc sulfate 3 lbs.
Hydrated lime 1 1/2 lbs.
Water 100 gallons
After planting, a complete fertilizer should be applied every 4 to 6 weeks during
the first year and every 60 days during the second year, except during the period
between November 15 to January 15. The type of mixture used should be modified or
supplemented according to the nature of the soil, For most Florida soils, mixtures
analyzing about 4% nitrogen (N), 7-9; phosphoric acid (P205), 3% potash (K20), and
1.5% magnesium (MgO), with at least 30% of the nitrogen derived from natural organic
sources are satisfactory. On soils that contain marl, the mixture should include
1 to 2% MnO (supplied from manganese sulfate). On muck soils, the nitrogen may be
- 4 -
eliminated or greatly reduced in the feeding program. The amount per application
should begin with 1/2 pound per tree and be gradually increased to 1 pound by the
end of the first year and 2 to 3 pounds per tree by the end of the second year.
Nutritional sprays containing copper and zinc should be applied 3 times a year during
the first two years. February, June and September are suggested as appropriate
months for applying such sprays. 'hen grown on marl soils guavas will benefit from
the addition of manganese sulfate to the spray to supplement the MnO added to the
For the initial applications, the fertilizer is broadcasted uniformly over an area
beginning 6 to 8 inches from the trunk of the tree and extending to the edge of the
watering basin. As the tree becomes established, the roots spread beyond the water-
ing basin and the fertilized area is widened accordingly.
Fertilizing Bearing Trees
Guava trees usually begin to bear fruit the third year.
Experimental data are lacking regarding fertilizer requirements for guavas growing
on the diverse soil types found in southern Florida. F'ron observations made in
bearing commercial groves thst are producing heavily, it is evident that fertilizer
practices used successfully on citrus on the various soil types will also give sat-
isfactory results when used on guavas. However, there is evidence that the guava
requires more nitrogen than common citrus, particularly during the periods when the
fruit is sizing. There is also little likelihood that the guava will be damaged by
overfertilization, provided minor element requirements are satisfied. Therefore,
it is probable that the grower will find it advantageous to supply extra nitrogen
just prior to the fruiting periods. Some varieties produce practically all of their
fruit during late summer to early winter. Others produce a second fairly heavy crop
during the spring months. The fertilizer practice should be modified accordingly.
The fertilizer mixtures used should contain at least 30 water soluble MgO and for
guavas on marl soils at least 1% MnO also. Annual applications of zinc and copper
supplied as nutritional sprays should be continued. In general, the higher the
poundage of fertilizer applied, the greater is the need for copper and zinc (and al-
so of manganese on marl soils). The grower should determine by observation whether
more than one application of the nutritional spray is needed per year.
Pruning and Irrigation
Some pruning of young trees is necessary. The guava ordinarily grows as a large
bushy shrub, but can be shaped into tree form by judicious pruning. As the bearing
trees become older, there is a tendency for the fruit to become smaller. The larg-
est fruit is borne on strong shoots of 2- to 3-year old wood. By moderate thinning
out and heading back of the top every 2 or 3 years, the production of.this type of
shoot will be stimulated and large fruit size may be maintained.
An ample supply of soil moisture during the fruiting season is required for maximum
fruit yield. If needed and used at this time, irrigation will greatly increase pro-
duction by increasing the size of the fruit.
Definite information is lacking concerning the best types of cultivation to be prac-
ticed in guava groves on all soil types. On limestone soils the growing of a cover
crop of native grasses or weeds which is mowed periodically and allowing the cut
material to decay on the ground surface is the most satisfactory practice. In most
sany soils, t-e-following the practice used in citrus groves, of allowing the cover
crop of native grass and weeds or of planted legumes to grow during the summer
period when rainfall is abundant should prove satisfactory. The cover is usually
mowed once during the summer or chopped in with a crop chopper. Plowing and deep
cultivation whereby guava roots are cut is undesirable because of the danger of
causing root suckering.
Algal spotting of leaves and fruits, caused by the parasitic alga, Cephaleuros vires-
cens, is rather severe on some types and varieties of guava, particularly in the hu-
mid coastal areas. Other varieties such as Supreme, show very little spotting.
Spraying with the nutritional spray reduces the infection considerably.
The guava is subject to rootknot caused by parasitic nematodes. The injury can be
overcome to a considerable degree by heavy fertilization combined with the use of
Copper deficiency causes attenuated growth and dieback and zinc deficiency is char-
acterized by little leaf and chlorosis. Correction follows the application of a
nutritional spray containing these elements.
The guava is subject to the attacks of numerous insects. The guava white fly,
Metaleurodicus cardini, and several species of scale insects are controlled by the
use of oil emulsions as used on citrus for scale and citrus white fly control,
In recent years the larvae of a tiny moth, Argyresthia eugeniella, have caused con-
siderable damage by tunneling through the fruit. Little is known concerning the life
history of this pest and control measures have not been worked out. Small pit-like
punctures through the skin of the fruit are caused by a small weevil, Anthonomus
costulatus, and larvae of this insect are sometimes found in the flesh. Control
measures have not been worked out for this insect.
The red-banded thrips is sometimes troublesome on the guava, causing defoliation
and fruit russetting when the infestation is heavy. Spraying with nicotine sulfate
1-800 or with Extrax or Syntone will effectively control these insects.
Other insects attacking guavas in Florida are an unidentified leaf-tier and a ser-
pentine leaf miner. These have not been serious enough to warrant applying special
control measures thus far.
Plant bugs occasionally sting the fruit, sucking the juices from the flesh. The
stung areas usually decay as the fruit ripens. Satisfactory control measures have
not been developed for control.