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
SMimeographed Repo t No. 12 February 1947
University of Florida
SUB-TROPICAL EXPERIMENT STATION i.
GROWING GUAVAS IN FLORIDA
Geo. D. Ruehle
Interest is increasing steadily in growing the common guava (Psidium guajava L.)
in Florida. Several rather large commercial acreages and a number of smaller
plantings are in bearing in southern Florida and additional acreage is being planted
at present. Manufactured guava products are being produced in a commercial way in
increasing quantities. It seems probable that the demand for such products will
continue to increase steadily, provided they are advertised to widen the market so
as to keep pace with expanded production. A small volume of fresh guavas are
shipped to northern markets.
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
trees. 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 one 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, salmon, pink or carmine. Seedling fruits vary from thin fleshed with a
large seed cavity 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 pec-
tin and acid and are superior for jelly making. Ascorbic acid content varies from
below 50 to more than 400 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 de-
termined 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 pre-
fer for the manufacturing of jelly or other products and propagate these by plant-
ing 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 one pound, which is inferior in
quality and low in ascorbic acid content. It is no longer recommended unless one
desires an especially mild flavored guava. No doubt there are many excellent seed-
lings in Florida which merit propagation as varieties but which have not been
brought to the attention of propagators or horticulturists.
Ruby and Supreme were crossed in 1945 and 130 seedlings of this cross have been
under observation at the Sub-Tropical Station. Several of these seedlings appear
to have qualities superior to either parent. One or more varieties will be named
from this cross in the near future. Air layered trees from a number of these trees
have been distributed to individuals and to other research groups, including the
University of Miami, in recent years, and one nurseryman is propagating and selling
layered trees under the name Ruby X Supreme hybrid.
Seed. 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 50-50 mixture of vermiculite and peat moss or with a sandy loam,
and covered to a depth of about inch. If soil is used, and it was not previously
sterilized, it is advisable to treat the seed with cuprons 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 trans-
ferred to individual containers where they should be grown until they are large
enough to set in the field.
Marcottage. The easiest vegetative method of propagating guavas is by air-layering
or marcottage. The method is quite rapid and is relatively simple. Limbs of 1 inch
or more in diameter are girdled by removing a strip of bark about 1.5 times the
thickness of the limb. The girdled area is bound with a ball of moistened sphagnum
several inches in diameter and 4 to 5 inches long, which is then tightly wrapped
with a sheet of translucent vinyl film and tied securely at each end with rubber
bands or string. The wrap is left attached until sufficient roots can be observed
through the plastic. Usually roots begin to form in 3 to 5 weeks. If they do not
begin to show after six weeks, the wrap should be removed and the girdled area ex-
amined. In some instances callous grows over the girdled area before root develop-
ment begins. Re-girdling and re-wrapping usually is followed by root formation in
a few weeks. After rooting is well advanced, the branch is cut off, pruned back,
and planted in a suitable container, and grown in partial shade until it is large
enough to plant in the field.
Budding and Grafting. Shield and patch budding and side-veneer grafting are
possible 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 1.5 inches long from
wood from which the green color has just disappeared from the bark.
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.
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 commend it. Stocks of this size are
readily topworkcd 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 collar of heavy paper around the stub and scion and
- 3 -
filling this with moistened peat moss, sphagnum, 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
top worked 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
Cuttage. Root cuttings 5 to 8 inches long cut from roots to -- 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. Leafy stem
cuttings of mature or nearly mature wood root with fair success in a constant moist
propagating box. After the rooted cuttings are removed from the box and transplant-
ed to soil, the plants should be kept in a constant mist chamber for a few days and
gradually removed to normal atmosphere. Comparatively little success has attended
attempts to root stem cuttings in an ordinary cutting bench, even with the use of
Another method of making a limited number of plants, is to sever roots 2 to 3 feet
Saway from the trunk with a spade or mattock, and sprouts will grow from the portion
cut off which may be transplanted later.
The guava can be grown successfully on a wide range of soils. It thrives on well
drained, loamy and muck soils, but willgrow vigorously on light sands, shallow lime-
stone and marl soils if properly fertilized. The guava will withstand temporary
flooding of the land and waterlogging of soil for considerable periods.
Experimental data are not available concerning planting distances for guavas grown
on all of the various soil types. Indications are that in commercial plantings
where heavy fertilization is to be practiced or where the soil is naturally fertile,
the trees should not be planted closer than 25 feet in rows 25 to 30 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 soils an 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 accommo-
date 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 nursery or plant container, the soil should be well packed and the tree
watered liberally as soon as planted to avoid air pockets. When the hole is com-
pletely 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 NON-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- lbs. (or its equivalent in some other neutral copper)
Zinc sulfate l3 bs.
Hydrated lime 1- 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
eliminated or greatly reduced in the feeding program. The amount per application
should begin with L pound per tree and be gradually increased to one 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 three times a year
during the first two years. February, June and September are suggested as appro-
priate months for applying such sprays. When grown on marl soils guavas will benefit
from the addition of manganese Sulfate to the spray to supplement the MnO added to
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 second or third year, and bearing
increases rapidly after the fourth year.
Experimental data are lacking regarding fertilizer requirements for guavas growing
on the diverse soil types found in southern Florida. From observations made in
bearing commercial groves that are producing heavily, it is evident that fertilizer
practices used successfullyon 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 clement requirements arc 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 3% 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
also 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 largest
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
sandy soils, 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.
Guava trees are attacked and usually killed outright rather quickly by a root and
crown rot caused by the gill fungus, Clitocybe tabescens (Scop. ex Fr.) Bros. This
fungus is parasitic on many species of living trees, and also flourishes as a
saprophyte in old roots or stumps of trees, especially oaks. Thorough removal of
tree roots, especially oak roots, when clearing timbered land prior to planting, is
the only method of avoiding this trouble. Clitocybe tabescens is absent in limestone
Ssoils from Miami southward, and appears also to be absent in muck soils of the
Everglades and in typical flatwoods sections, where pine is the dominant tree and
oaks do not occur.
Algal spotting of leaves and fruits, caused by the alga, Ccphaleuros viroscens Kunze,
is rather severe on some types and varieties of guava, particularly in the humid
coastal areas. Other varieties show very little spotting. Spraying with the nutri-
tional spray in the spring reduces the infection considerably.
Mummification and blackening of immature fruit attributed to the parasitism of a
species of Glomerella is reported as a rather common disease in Puerto Rico. A
similar trouble has been observed occasionally in Florida. Colletotrichum
gloeosporioidcs Pcnz., and several unidentified fungi are associated with decays of
mature fruit. Frequently such infections are initiated at insect stings or at cracks
developing in the skin after heavy rains.
The guava is subject to rootknot caused by parasitic nematodes. Injury can be over-
come to a considerable degree by heavy fertilization combined with the use of
Copper deficiency is manifested by attenuated growth and dieback induced by heavy
feeding of NPK fertilizers and the inability of the tree to obtain sufficient copper
to balance the major elements. Zinc deficiency is characterized by little leaf and
chlorosis. Correction of these troubles follows the application of a nutritional
spray containing copper and zinc.
The guava is subject to the attacks of numerous insects. The life history and con-
trol for many of these pests still remains to be worked out.
The guava whitefly, Metalcurodicus cardini (Back), and the numerous species of scale
insects attacking guava are controlled by the use of l- percent oil in spray or by
spraying with parathion wettable, at the rate of one pound 15% or equivalent per
100 gallons of water. In the case of whitefly the sprays should be timed when larvae
are found on leaves, or about two weeks after flights of adult whiteflies. Sprays
for control of scales should be applied when severe infestations are noted.
The redbanded thrips is often troublesome on the guava, causing defoliation and fruit
russetting when infestations are heavy. Spraying with lindane wettable at one pound
of 25 percent active ingredient or its equivalent per 100 gallons of water, or with
chlordane wettable at two pounds 50 percent active ingredient or its equivalent per
100 gallons of water will give control. The sprays should be applied when the fruit
is small or when infestations are noted.
In recent years the larvae of a tiny moth, Argyrcsthia eugeniella, have caused con-
siderable damage by tunneling through the fruit. Little is known concerning the
life history of this pest. It has been observed that the incidence of tunneling
increases steadily during the fruiting season, so presumably the life cycle is short.
Spraying with DDT wettable at two pounds 50 percent active ingredient or its equiva-
lent per 100 gallons of water at approximately two week intervals from the time the
fruit was small until near maturity apparently practically eliminated infestation
in an exploratory trial.
Small pit-like punctures through the skin of small green 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.
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. Parathion applied for whitefly control apparently also
controls these pests.
Plant bugs occasionally sting the fruit, sucking the juices from the flesh. The
sting areas usually decay as the fruit ripens. Satisfactory control measures have
not been developed for control.