One Thousand Questions in California Agriculture Answered Part 22

Walnuts in Alfalfa.

Will the walnut trees be injured in any way by irrigating them at the same time and manner as the alfalfa - that is, by flooding the land between the checks? Will the walnuts make as good a growth when planted in the alfalfa, and the ground cultivated two or three feet around the tree, as though the alfalfa was entirely removed? Is it advisable to plant the trees on the checks rather than between the checks?

Walnut trees will do well, providing you do not irrigate the alfalfa sufficiently to waterlog the trees; providing also that you do use water enough so that the trees will not be robbed of moisture by the alfalfa.

This method of growing trees will be, of course, safer and probably more satisfactory if your soil is deep and loamy, as it should be to get the best results with both alfalfa and walnuts. It would be better to have the trees stand so that the water does not come into direct contact with the bark, although walnut trees are irrigated by surrounding them with check levees. Planting walnut trees in an old stand of alfalfa is harder on the tree than to start alfalfa after the trees have taken hold, because the alfalfa roots like to hang on to their advantage. In planting in an old field, we should plow strips, say, five feet wide and keep it cultivated rather than to try to start the trees in pot-holes, although with extra care they might go that way.

Walnuts in the Hills.

Will walnuts grow well in the foothill country; elevation about 600 feet, soil rich, does not crack in summer and seems to have small stones in it?

Walnuts will do well providing the soil or subsoil is retentive enough.

If you have water available for irrigation in case the trees should need it, they would do well, but if the soil is gravelly way down and likely to dry out deeply and you have no water available an opposite result might be expected. It is a fact that on some of the uplands of the coast mountains there is a lack of moisture late in the season which interferes with the success of some fruit trees.

To Increase Bearing of Walnuts.

We have a walnut orchard which does not bear enough nuts. The trees are all fine, even trees, 10 and 12 years old, and we are told that the crop was light this year because the trees were growing so vigorously and put most of their energy into the new wood. Is there any special fertilizer which will make the trees bear more and not prompt such heavy growth?

If your adviser is right that the trees are not bearing because of excessive growth, it would be better not to apply any fertilizer during the coming year, but allow the trees to a.s.sume more steady habit and possibly even to encourage them to do so by using less cultivation and water. If you wish to experiment with some of the trees, give them an application of five pounds of superphosphate and two pounds of potash to each tree, properly distributed over the land which it occupies. You certainly should not use any form of nitrogen.

Temperature and Moisture for the English Walnut.

What amount of freezing and drouth can English walnuts stand? Under what conditions is irrigation necessary?

The walnut tree will endure hard freezing, providing it comes when the tree is dormant, because they are successfully grown in some parts of the Eastern States, though not to a large extent; but the walnut tree is subject to injury from lighter frosts, providing they follow temperatures which have induced activity in the tree. On the Pacific Coast the walnut is successfully grown as far north as the State of Was.h.i.+ngton, but even in California there are elevations where frosts are likely to occur when the tree is active, and these may be destructive to its profit, although they may not injure the tree. You are not safe in planting walnuts to any extent except in places where you can find trees bearing satisfactorily. Planting elsewhere is, of course, an enterprising experimental thing to do, but very risky as a line of investment. Irrigation is required if the annual rainfall, coupled with the retentiveness of the soil and good cultivation, do not give moisture enough to carry the tree well into the autumn, maintaining activity in the leaves some little time after the fruit is gathered.

Walnuts from Seed.

There is a reliable nursery company selling seedling Franquette walnut trees on a positive guarantee that they will come true to type. Are orchards of this kind satisfactory?

Walnuts do come truer to the seed than almonds and other fruits and the Franquette has a good reputation for remembering its ancestry. Until recently practically all the commercial walnut product of California was grown on seedling trees. But these facts hardly justify one in trusting to seedlings in plantings now made. The way to get a walnut of the highest type is to take a bud or graft from a tree which is bearing that type.

High-grafted Walnuts.

What is the advantage of a high-grafted walnut? I am about ready to plant 10 acres to nuts and do not know whether to purchase Franquette grafted high on California Black or not.

The advantage of grafting English walnut high on California Black walnut consists in securing a main trunk for the tree, which is less liable to sunburn and probably hardier otherwise than is the stem of the English walnut, and the present disposition toward higher grafting or budding seems therefore justified and desirable.

Grafting and Budding the Mulberry.

What is the most approved manner of grafting mulberry trees? Am told that they are very difficult to successfully graft.

Most propagators find the mulberry difficult by ordinary top and cleft grafting methods. A flute or ring graft or bud does well on small seedlings - that is, removing a ring or cylinder of the bark from the stock and putting in its place a cylinder from the variety desired, cut to fit accurately. For large trees this would have to be done on young shoots forced out by cutting back the main branches, but when this is done ordinary s.h.i.+eld budding in these new shoots would give good results. Cut back the trees now and bud in the new shoots in July or August.

Hardiness of Hybrid Berries.

How much cold will Phenomenal, Himalaya and Mammoth blackberries stand in winter? Is it safe to plant where the temperature goes below 32 degrees?

These berries are hardy to zero at least, for they are grown in northern parts of this coast where they get such a touch once in a while. They have also endured low temperatures in the central continental plateau States and eastward. Whether they can endure the lowest temperatures of the winter-killing regions of the northern border cannot be determined in California, for we do not have the conditions for such tests. The berries are very hardy while dormant, and probably their value in colder regions would depend rather more upon their disposition to remain dormant than upon what they can endure when in that condition.

Pruning Himalayas.

Shall the old wood be cut away in pruning Himalayas?

All the old wood which has borne fruit should be cut out in the fall and new shoots reduced to three or four from each root, and these three or four shoots should be shortened to a length of ten or twelve feet and be trained to a trellis or fence, or some other suitable support. Vines which are allowed to grow riotously as they will, are apt to be deficient in fruit bearing.

Strawberries with Perfect Flowers.

Has Longworth Prolific an imperfect bloom? I have Longworths in bearing which apparently are perfect. Is there another strain of Longworth that are not self-fertilizing?

The Longworth Prolific strawberry has both staminate and pistillate elements. Possibly some other variety, because of its resemblance to Longworth and the popularity of it, may have been wrongly given its name. Most of the varieties which are largely grown in California are perfect in blossom, though some of the newer varieties need a.s.sociation with pollinizers.