The California fruits and how to grow them

Front matter

CALIFORNIA JR s o

I

I

Preface

The Seventh Edition of this treatise has shared the good fortune of its immediate predecessors in meeting a public demand which covered the available supply much sooner than anticipated. Because of the desirability of keeping the work abreast of the progress of a constantly changing and developing industry, the publishers have assumed the burden of resetting the type for each edition, resisting the temptation of greater profit which would attend reprinting from plates with minimum revision. Therefore this edition is wholly set anew — the eighth opportunity for free revision which the writer has enjoyed during the publication of the work, which has reached a total of twenty-two thousand copies since the appearance of the first edition in 1889.

Of the quality of the book, it does not become the writer to speak, but he may express his satisfaction at its popularity. Its circulation may be cited as a testimonial of its suitability for service in the building up of the fruit industries, and the demand for it may be regarded as rather unique, when it is remembered that the book deals exclusively with the fruit growing of a single State which is only one, although it be the greatest, of the agricultural interests of that State. The demand for the book is an exponent of the continued activity in California fruit planting, and its sale abroad indicates the fact that the outside world is watching California 's fruit development, and desires to know the methods by which a product with a commercial valuation of more. than $225,000,000 was secured in 1918.

The writer repeats the request which he has made in earlier editions that all readers whose observation and work teach them any better way than he has described in this book shall share with him the advantages of such greater wisdom.

EDWARD J. WICKSON.

Berkeley, August, 1919.

PART ONE: GENERAL. Chapter

I The Climate of California and Its Modifications.

II Why the California Climate Favors the Growth of Fruit.

III The Fruit Soils of California.

IV The Wild Fruits of California.

V The California Mission Fruits.

VI California's Leadership in American Fruit Industries.

FART TWO: CULTURAL.

VII Clearing the Land for Fruit.

VIII The Nursery.

IX Budding and Grafting.

X Preparation for Planting.

XI Planting of Trees.

XII Pruning Trees and Thinning Fruit.

XIII Cultivation.

XIV Fertilizers for Trees and Vines.

XV Irrigation of Fruit Trees and Vines.

Chapter I The Climate Of California And Its Local Modifications

In climatic conditions affecting horticulture we have in California almost an epitome of all other parts of the United States, with added climatic characters which no other part posseses. We have high mountain valleys with wintry temperature-conditions, where only hardy northern fruits can be grown ; we have hot valleys where the date palm confidently lifts its head to the fiery sunshine, while its feet are deeply planted in moist substrata beneath the sandy surface ; but we can not claim tropical conditions, because our dry air denies us many strictly tropical growths, although we have frostless sites for them. Intermediate between the cold and snow of the mountains and the heat and sand of the desert, we have every describable modification and gradation, and, naturally, it is between these extremes that our richest inheritance of horticultural adaptation lies.

When the breadth and scope of our horticultural adaptations are realized, it becomes apparent that an enumeration of the fruits we can grow successfully would be, in fact, a catalogue of the known fruits of the world, except those which are strictly tropical. Wherever there is a northern or southern departure from the equator sufficient to bring energy to mankind, or where the same is accomplished by elevation upon tropical mountainside or plateau, there also are fruits which find a welcoming home in California, and are improved by the intelligent cultivation and selection which here prevail. On the other hand, it has been abundantly demonstrated, during recent years, by official awards at great exhibitions and by the sharp criteria of the markets as well, that the fruits of wintry regions are quite as much benefited by transfer to proper locations in California as are the people who come to grow them. From north and south alike, then, California makes grand acquisitions and includes within her area the adaptations of the whole country, with some which no other State possesses.

But while this horticultural scope is claimed for the State as a whole, it is necessary to add that local adaptations within the State must be very narrowly drawn. Our greatest failures have followed ill choice of location for the purpose intended. Whenever certain California fruits have been ill spoken of, they have been produced in the wrong places, or by ill-advised methods. It is possible, then, to produce both poor and perfect fruit of a given kind. It may be said this can be done anywhere by the extremes of culture and neglect, but to this proposition it must be added that in California equally excellent methods and care may produce perfection in one place and the opposite in another. One who seeks to know California well must undertake to master both its horticultural greatness and littleness ; and so closely are these associated, and so narrow the belts of special adaptations, that there are many counties which have a range of products nearly as great as the State itself.

It is hard for the stranger to realize this. It is difficult for him to believe that the terms "northern" and "southern" have almost no horticultural significance in California ; that northern fruits reach perfection, under proper conditions, at the south, and vice versa ; that some regions of greatest rainfall have to irrigate most frequently ; that some of greatest heat have sharpest valley frosts ; that some fruits can be successfully grown through a north and south distance of 300 miles, but can not be successfully carried a few hundred feet of either less or greater elevation ; that on the same parallel of latitude within a hundred miles of distance, from coast to mountainside, one can continuously gather marketable Bartlett pears for three months — not to mention the second crop, from belated blossoms, which is often of account on the same trees in the same season.

Through the multitude of local observations, which seem perplexing and almost contradictory, it is possible to clearly discern certain general conditions, of both nature and culture, which may be briefly advanced as characteristically and distinctively Californian.

The climate of the Pacific Coast is described by the meteorologist as "insular or moderate," as contrasted with the "continental or excessive" climate of the regions east of the Sierra Nevada. The west coast of Europe is also insular in its climate. The northern limit of an annual mean temperature of 50 degrees Fahr. is 50 degrees and 47 degrees of north latitude on western coasts of Europe and America respectively. But though there is this similarity in mean annual temperature, there is a decided advantage pertaining to our climate over that of west Europe in that our range of temperature is less ; that is, extremes of heat and cold are nearer together, and changes are therefore much less excessive. This characteristic

TOPOGRAPHY AND CLIMATE H

of our local climates is due in the main to two great agencies, one active, bringing heat, the other passive, shielding us from arctic influences.

First : Our proximity to the Pacific Ocean. Professor Alexander G. McAdie, for twenty years in charge of the San Francisco office of the United States Weather Bureau, and now Professor of Meteorology at Harvard University, says of the mildness of the California climate: "The Pacific Ocean is a great natural conservator of heat, the mean annual temperature of which near the California Coast ranges from 50 degrees to 60 degrees F. The strength of the westerly winds which prevail on the California Coast for more than half the days of the year is due to the fact that the whole drift of the atmosphere is prevailingly from the west to east. The climate of west coasts is consequently less severe than the climate of east coasts."*

Second : Another agency contributing to the mild climate of the Pacific Coast consists in the mountain barriers upon our northern and eastern boundaries. It was Guyot who first called attention to the fact that the Sierra Nevada and the Cascade Mountains reach the coast of Alaska and bend like a great arm around its western and southern shore, thus shutting off or deflecting the polar winds that otherwise would flow down over the Pacific Coast States, while California has her own additional protection from the north in the mountain arch which has its keystone in Mount Shasta.

CHIEF TOPOGRAPHICAL AND CLIMATIC DIVISIONS OF

CALIFORNIA

California is usually divided into three main areas and climates, each distinct in typical conditions and yet separated by regions, more or less wide, in which these conditions merge and influence each other. Dr. Robertson says :t

Isothermal lines which normally run east and west are, as they near the Pacific, deflected north and south, and define three distinct climatic belts. These may be named coast, valley and mountain; and while they resemble each other in having only two seasons, they are dissimilar in other respects. These differences depend upon the topography of the country, and are of degree rather than of kind; altitude, distance from the ocean, and situation with reference to mountain chains, giving to each region its characteristic climate.

How similar are the conditions which prevail in these belts may be learned from the data shown in the following table, which includes points separated by nearly the whole length of the State, the difference in latitude of the extreme north and south points being seven or eight degrees. Thus, through a north or south distance great as that which separates the States of Georgia and New York, similar climatic conditions prevail in California. In the following

•"The Rainfall of California," University of California Publications in Geography, 1914. tReport of State Agricultural Society, 1886, page 322.

table the averages are deduced from observations by the United States Weather Bureau observers for a long series of years :

Seasonable and extreme temperatures and average rainfall in various California regions from the records of the United States Weather Bureau to the close of 1918.

5 8

STATIONS.

H COAST—

Eureka Humboldt 64

San Francisco. San Francisco ... 155

San Jose Santa Clara 95

King City Monterey 333

Santa Barbara . Santa Barbara ... 130

Los Angeles. .. Los Angeles 293

San Diego San Diego 87

VALLEY—

Shasta 552

.Sacramento 71

Merced 173

.Fresno 293 g E

£8 % c8 s-i c3 c3 rt bo O bo 9 fajo a gS S6

FOOTHILL AND MESA—

Auburn Placer 1360

Redlands San Bernardino ..1352

Redding. . . .

Sacramento.

Merced

Fresno

47 50 56 54 51 85 20

51 55 59 59 55 101 29

50 57 67 60 58 108 18

49 57 66 60 58 116 14

55 58 65 63 60 115 27

55 60 70 65 62 109 28

55 59 68 63 61 110 25

47 60 80 64 63 112 18

47 59 72 62 60 110 19

49 61 79 65 63 116 16

47 60 79 64 63 115 17

2 c

35.8 20.1 10.7 9.7 10.4

33.9

14.9

LOCATIONS FOR THE GROWTH OF DIFFERENT

FRUITS

It is intended to describe as definitely as possible the locations suitable for the growth of different fruits in the special chapters given to those fruits, but there are a few general conditions which should be outlined.

In discussing the choice of location for an orchard it is not intended to speak geographically. As has already been intimated, latitude, which is a prime factor in geography, is of exceedingly small account as an indication of horticultural adaptations in California. The fact becomes strikingly apparent when it is known that the apple and the orange, fruit kings whose kingdoms lie at opposite borders of the temperate zone, so far distant that one may be called semi-frigid and the other semi-tropical, have in California utter disregard for the parallels of latitude, which set metes and bounds upon them in other lands, and flourish side by side, in suitable localities, from San Diego to Shasta. Impressive as this truth may be, it is not so startling as, another fact, viz., that fruits, in suitable interior situations, ripen earlier at the north than in coast valleys at the south.

"That almost any extreme of weather," says Professor McAdie in his publication just cited, "can be found within the limits of Cali-

CALIFORNIA COAST CLIMATES 13

fornia is readily comprehensible when it is considered that the state is 800 miles in length, contains a hundred million acres, and varies from deserts as much as 280 feet below the sea to Shasta 14,380 feet, or the High Sierra, where 66 peaks exceed 10,000 feet in height, while 40 exceed 13,000 feet, and Mount Whitney rises to 14,502 feet."

It is apparent, then, in view of such diversity, that the selection of locations for orchards must be made with a knowledge of special conditions governing the distribution of equal temperatures and other natural agencies contributing to the development of fruit. This distribution, as has been intimated, is not by parallels of latitude, great circles which appear as straight lines on a map, but by curves, which proceed in various directions, governed chiefly by topography. These are curves of temperature, of rainfall, of elevation, of soil formation and deposit. Geography must be interpreted by topography and climatography.

Let these ruling conditions be reviewed, then, briefly : First, as to general areas ; second, with reference to special situations and locations.

COAST CLIMATE

The chief characteristics of the coast are equable temperature, increasing southward ; summers cool and winters warm, as compared with the interior; abundant rainfall, decreasing considerably southward ; a somewhat humid atmosphere, as compared with the interior ; frequent fogs or overcast skies ; prevailing westerly winds.

The extension of coast influence toward the interior is governed by local topography. Coast valleys open to ocean winds are cooler and moister and demand hardier fruits than valleys sheltered by intervening ranges. Gaps and passes in the ranges are subject to winds of considerable force and low temperature, and are not generally favorable for fruit; on the other hand, situations sheltered on the north and west favor growth of fruits even though quite near the coast. Sometimes a distance of a few miles, sometimes a windbreak or natural forest, or of planted trees, so modifies coast influences that fruits do well. Elevation on the sides of coast valleys secures similar results. For example, the floor of the Pajaro Valley is well suited for apples, late pears, cherries, plums, prunes, and berries (except gooseberries), while on adjacent hillsides peaches do well.

In Southern California, coast winds are warmer than in the upper half of the State, but coast influences intrude farther, as a rule, because the hills near the coast in Southern California are low ; the high ranges, answering to the Coast Range of the upper part of the State, trending far into the interior. On the coast side of these ranges fruits ripen later than in sheltered interior points in the upper part of the State, but eastward of the mountains, where soil and moisture favor, or irrigation is practised, extra early locations have been found and are now being rapidly developed — in the Imperial and adjacent valleys, for instance.

Some of the horticultural effects of the conditions prevailing on the coast may be described as follows :

Late Ripening of Fruits. — The late ripening of fruits west of the mountains in Southern California has just been mentioned. Intrusion of coast influences has the same effect in more marked degree at the north because the ocean winds are colder. Directly on the coast, at Pescadero, San Mateo County, for example, fruits ripen about a month later than in Santa Clara Valley, which is just across the Coast Range. Napa Valley, though about forty miles inland and sheltered by ranges of hills, still is sufficiently affected by the coast influences to mature, fruits considerably later than Vaca Valley, ten or fifteen miles further east, beyond a higher range, which completely bars out these influences. Similar local effects are found in Southern California. For instance, in Ventura County, in a canyon sixteen miles from the ocean, and at an elevation of sixteen hundred feet, fruits ripen three weeks earlier than on the coast or in the 'valleys opening thereon.

Failure of Certain Fruits. — Though killing frosts are few directly on the coast, the deficiency in summer heat and sunshine renders some fruits unsatisfactory. This is especially the case in the upper coast region. Grapes and figs ripen imperfectly, while but a short distance back from the coast, in situations sheltered by ridges parallel to the coast, they do well. Elevation sometimes produces corresponding effects.

Pests and Diseases. — Certain blights are more prevalent under coast conditions. The scab blight of the apple, the curl-leaf of the peach, and some other blights, are prevalent on the coast and in coast valleys, on the river bottoms in the interior, and on the mountains, and less serious, or wholly absent, in the hot interior valleys. Some insects prefer the coast but thrive also in the interior, as hot dry wind is excluded by dense growth of the tree and the included air becomes moister above irrigated soil. A notable instance is the black scale, which, with the black smut which attends it, has long been a grievous pest of growers of olives and citrus fruits, and has recently became prevalent on deciduous fruit trees in some regions. On the other hand, in the face of ocean winds the codlin moth seems to have less chance to fill pears and apples with her destructive offspring than she enjoys in interior valleys and mountain regions. Directly under coast influences, moss and lichens gather quickly and should be removed. Spraying with alkaline washes not only kills insects but cleans the bark from parasitic vegetable growth. Although fruit trees on the coast are not so subject to sunburn as in the interior, there is especial value in low heading to withstand winds ; there should also be plenty of room given the trees, that sunshine may have free access to warm the ground all around the tree, which may be undesirable in the interior.

INTERIOR CLIMATES OF CALIFORNIA 15

VALLEY CLIMATE

The characteristics of the interior valley climate are higher summer and lower winter temperatures than on the coast, the range of temperature being nearly the same both north and south ; rainfall abundant in the north and decreasing rapidly southward, so that as a rule the interior valleys in the south half of the State require irrigation ; very dry air and almost constant sunshine, freedom from fogs and from dew in summertime ; winds occasionally strong, hot, and desiccating in summer and cold in winter.

Local Modifications. — The term " valley climate" is broad, and includes everything away from the coast to a certain elevation on the slope of the mountains. Certain small valleys protected from cold northerly winds and from fog-bearing westerly winds and open to the spring sunshine, have a forcing climate which produces the earliest maturing fruit of the season ; earlier not only than the coast and the mountain, as has been stated, but also somewhat earlier than adjacent locations in the broad, open valley. Slight elevation, even on the sides of small valleys, frequently secures freedom from winter frosts and ministers to early ripening. Elevation above sea-level on the rims of great valleys also secures similar results and gives rise to thermal belts in which semi-tropical fruits are successfully growing even as far north as Shasta County. On the floors of great valleys moderating influences are secured on the lee side of wide rivers and by planting on the river bank or on slightly elevated swells rather than on the level, open plain. The river bottom lands of the great valleys, though subject to severe frosts, are freer from the effects of desiccating winds than the open plains ; they are, however, more favorable to the spread of certain blights than the plains.

Some of the horticultural effects of valley conditions are as follows : Early ripening and perfection of summer and autumn fruits, owing to continual sunshine and dry air ; forced maturity of certain fruits, as apples for instance, which destroys character and keeping quality; injury from sunburn and hot winds in summer, which seriously affect both fruit and foliage of some varieties; occasional injury to tender fruits (semi-tropicals) and to young trees of hardy fruits, which have been kept growing late in the season, from low temperature, which sometimes is reached suddenly on the floor of the valleys ; freedom from some blights and insects which are prevalent on the coast, but not from others. Many of these minor troubles are, however, counterbalanced by the earliness, size, beauty, and quality of certain fruits, and by the most rapid and successful open-air drying of fruits, owing to high autumn temperature, the freedom from summer fog, dew and generally from rain during the drying season.

FOOTHILL CLIMATE

Foothill climate is usually considered as a modification of valley climate. It has been shown that up to about two thousand five hundred feet, on the western slope of the Sierra Nevada, the seasonal temperatures are quite like those of the valley, but the rainfall increases about one inch for each hundred feet of elevation. There are, however, in the foothills, places where early spring heat and freedom from frost give very early ripening fruits, and other places at the same elevation where winter temperature drops below the valley minimum, and where late frosts also prevail. This is governed by local topography. In many of the small valleys among the foothills, both of the Sierra Nevada and the Coast ranges, frosts are more severe than on the hills adjacent or in the broader valleys to which they are tributary. These small "protected valleys" are apparently warm and cozy for early blooming deciduous and citrus fruits, but they are really very dangerous. They frequently have such narrow and obstructed openings that cold air is dammed up over their lower lands and frosts are more severe and later than in valleys which have ample and free outlets and seem less protected.

Of course the disposition of cold air to settle in low places and to flow down canyons and creek-beds while the warm air rises and bathes the adjacent hillsides, has much to do with the frost in the hollow and the freedom from it on the hills. The constant motion of the air on the slopes is also a preventive of frost, providing the general temperature is not too low. It is not uncommon to find in deeper valleys, protected against the western wind, flakes of snow and a wintry chill, with dormant vegetation, while one thousand feet higher up the foliage is fast developing.

MOUNTAIN CLIMATE

Above an elevation of two thousand five hundred to three thousand feet, conditions gradually intrude which resemble those of wintry climates. The tender fruits, the apricot, peach, etc., become liable to winter injury and give irregular returns, or as greater elevation is attained, become wholly untrustworthy. Early blooming of these fruits during warm spells which are followed by severe frosts, renders the trees unfruitful. At four thousand to four thousand five hundred feet the hardy apple and pear flourish, ripening late, and winter varieties possessing excellent keeping qualities. Here, however, winter killing of trees begins and locations even for hardy fruits have to be chosen with circumspection.

There are elevated tracts of large extent among the Sierras where the common wild plum, choke-cherry, gooseberry, and California chestnut are produced abundantly. April frosts have killed the fruit of those same plums, transplanted to lower ground, while those left in their natural situation were quite unharmed. It has been observed that these plum trees with other fruits and nuts in their original positions, invariably occupy the broad tops of the great ridges instead of the sides and bottoms of ravines or narrow, pent-up valleys. Follow nature in the choice of orchard sites (with due regard to a supply of moisture in the soil, either natural or artificial) and little hazard attends the culture of the hardier fruits of our latitude among the highlands of the State that is incident to other

AUTUMN COLORS NOT DUE TO FROST 17

seemingly more favored localities. The beauty and quality of these mountain fruits are proverbial.

A RULE OF GENERAL APPLICATION

What has been thus suggested of the great variation of temperature conditions within narrow limits should lead to the conclusion that not only must the kind of fruit to plant be determined by local observation and experience, but often varieties of these fruits must be chosen with reference to adaptation to local environment. For this reason it is impossible to compile tables of varieties suited for wide areas — and yet it is true that some varieties have shown themselves hardy and satisfactory under all conditions. These facts will be shown by the discussion which will be given to each of the different fruits.

REST AND ACTIVITY OF FRUIT TREES

Indication has already been made of regions adapted to the growth of early and of late fruits. There is, of course, difference in time of rest and of returning activity in blooming. On the mountains under wintry conditions the trees leaf out and bloom late, following more or less the habit of Eastern trees. In the foothills, the valleys, and the coast, there is less difference in time of rest and of leaf and bloom. Even in regions where there may be a month 's difference in ripening of fruit, as, for example, in the Vacaville district, fifty miles inland, and in Berkeley, two miles from the bay shore, trees bloom almost at the same date. The difference in ripening is due to the higher temperature and fuller sunshine of the interior situation, which have a forcing effect, while the low temperature and dull skies of the summer on the coast retard maturity.

The rest of the tree, in all save the mountain district, is not dependent upon the touch of frost. It comes rather from thirst than from cold. The immense weight of fruit, the vigorous growth of wood, and the exhaustion of moisture from the soil by the draught of the roots to compass this growth, are the chief causes which bring the sere and yellow leaf in California. It is not frost, for the petunias may be blooming and the tomato' vines still green in the fields. But the time has come for a rest. The trees sleep ; but merely as a nap at midday; the early rains wake them soon. The roots are active first, then the buds swell, and the blossoms burst forth — sometimes as early as January — the almond first heralding the advent of California's springtime.

Sometimes this season of rest is too short for the good of the tree or vine. The early rains, when followed by a spring-like temperature, as sometimes happens, induce activity in the top as well as the root, and the tree is not in condition to withstand cold weather, which may follow. It is probable that such stimulated activity, suddenly checked, is responsible for more ills to tree and vine than are usually attributed to it. Both to insure hardiness and fruitfulness it is important that a tree shall have summer moisture enough to finish its late summer and early autumn growth-processes. Reference to this important matter is made in the chapter on irrigation.

Chapter II Why The California Climate Favors The Growth Of Fruit

It is pointed out by the earliest students of meteorology, as related to horticulture, that perfect development of fruits depends upon certain atmospheric conditions, which are included in the term climate : First, temperature ; second, light ; third, humidity or atmospheric moisture, — considered wholly apart from soil moisture. It was also shown that temperature and humidity should be equable, or as free as possible from excessive extremes or rapid changes.

Obviously, the chief characteristics of the California climate are : First, freedom from extremes of low temperature ; second, an abundance of sunshine ; and third, atmosphere with a low percentage of humidity. It will be interesting to introduce enough statistics to demonstrate these claims, and to cite reasons why these conditions are of special value to the fruit grower.*

THE OFFICE OF HEAT IN FRUIT PRODUCTION

Temperature conditions may preclude the success of a fruit tree either by destroying it outright, by dwarfing it, or by preventing it from setting or ripening its fruit. Extremes of temperature accomplish the death of plants, and insufficient or excessive mean temperatures may prevent fruition without killing the plant. The first quality of the California climate to arrest the attention of fruit growers in the states east of the Rocky Mountains is the freedom from the effects of the extremely low winter temperatures, to which is due the deplorable failure, in the eastern and western states, of many of the fruit varieties from the west of Europe, and to escape which such zealous efforts are now being so successfully put forth to secure hardy varieties of native and foreign origin.

How slight is the injury from low temperatures in all parts of the State where fruit is largely grown may be seen from the following compilation of extreme low temperatures at different points approximately at the same latitude on the coast, in the interior valleys, and on the foot-hills.

Lowest Temperatures at Several California Points.

Coast and Coast Deg\ above Deg\ above Deg\ above

Valleys — zero. Interior Valleys — zero. Foothills — zero.

Eureka 20 Redding 18