The Filbert and Persian Walnut in Indiana

W. B. Ward, Department of Horticulture, Purdue University

The soils and climatic conditions in Indiana are, for the most part, favorable to the growing of nut trees. There are various types of soils, ranging from light sand to heavy clay, soils high and low in organic material and natural fertility. The annual rainfall, 35 to 40 inches, is fairly well distributed throughout the year. The length of the growing season is about 150 frost-free days and, oftentimes, another 20 to 30 days of non-killing temperature. The summer and winter temperatures are average, thus providing good conditions for the development of fruit and growth to the trees.

There are always exceptions to the normal conditions, and a good test season broadens the experience of those who want to go to the extreme in planting nut trees. This past year, 1950-51 season, was a good test year. The temperature early in November was as high as 85°, tomatoes, peppers, beans, and sweet corn were growing in the gardens. During mid-November the temperature quickly dropped to near zero. The cold later went down to -20° and even -35°, as recorded at Greensburg. This cold weather, not only killed much of the tender short growth and pistillate flower possibilities, but destroyed many of the catkins. The filbert and Persian (including Carpathian) walnuts, suffered and in some instances the plants were killed to ground level. All of the damaged plants have survived, and where the top of the tree was killed, new growth came up from the root. As only seedling Persian walnut trees were under observation and included in the Purdue plantation, their sucker growth will be used to form new tops.

The native walnut, hazelnut, hickory, and butternut had little or no winter injury and many trees are very fruitful all over Indiana. The improved strains of filberts and the Persian walnuts have only a few fruits this year. Seedling Persians grafted or budded on native black walnut survived, but there was some damage to the top growth due to immaturity of the wood and bud last fall. Before general planting recommendations can be made, other than for the hobbyist or home-owner with a few trees, further testing will be required.

Filbert and Hazelnut

The native hazelnut thickets are not as common now as in years past. Most of the nuts were small and of little commercial value. When hybridizers and other nut enthusiasts started improving the size and quality of the native hazelnut and bringing in filberts from other countries, some impetus was added to the filbert planting program. Only a few took advantage of these new and promising seedlings, and aside from a few small plantings throughout the state the filbert is placed in the ornamental grouping of plants. Several areas in Indiana are suitable for more extensive plantings. The Jones hybrids have proven satisfactory and are found growing from the northern part to the Ohio River.

Several crosses were made four years ago using pollen from the Rush and large fruited seedlings on the native hazel. There are 35 or 40 such plants, two years old, now growing in the Purdue plot. They came through the winter in excellent condition. Many of the catkins on the older plants were killed during the early cold spell, and the nut crop this year is very spotty. The filbert does have a place around the home as an ornamental, as a fruit tree, or when used as a hedge for screening.

The Carpathian Persian Walnut

The Carpathian Persian walnuts in Indiana are practically all seedlings. Many of these seedling trees show great promise, while others under observation for the past few years are being discarded because of lack of hardiness and production. Some few seedlings made vigorous growth and produced fair to good yields for the past 10 years, but some weakness was evident after the 1950-51 winter. It appears now that those trees that have survived and are in production this year are worthy of further study and propagation.

The oldest known Persian walnut in our state is the Haderle seedling. A few nuts, from a friend in California, were planted in 1924 and 10 years later fruited. This tree has produced as many as 350 pounds of nuts in a single year and has survived all test winters since planting. The nut from the Haderle tree averages 32 nuts per pound, medium shell, good quality and 44.6 per cent of the total weight is edible. The nut cracks well. Several other such Persian seedlings have been classified as existing prior to the general distribution of Carpathian nuts from the Wisconsin Horticultural Society in 1936 to 1938 and later.

Several individuals in Indiana took advantage of the nut sale and importation from Poland during the years mentioned and about 10 per cent of the original seedlings are now alive. Many of the trees planted 10 to 15 years ago are fruiting and classified. Outstanding groups of seedlings, which are referred to by name, such as Bolten, Fateley, Eagles, Barnhart, Kraning, Behr, Zollman, and others are found from the extreme northern area to the Ohio River, and are distributed over nearly one-half of the 92 counties in Indiana.

The use of eastern black walnut as understock has been practised by several orchardists and nurserymen, and a few will have trees for sale in the near future. The fruits from these trees compare with the best.

The largest nut is in the Fateley #1., with some fruits two inches in diameter, and averaging 23 nuts per pound. The nut is high in quality, has an appealing taste, and a well formed kernel. It cracks easily and has a very thin shell for such a large nut. This tree has borne 50 pounds of nuts or more annually for the past few years and has a nice crop this year after the severe test winter. The Fateley #1 seedling as well as the #2, #3 and #4 seedlings, are grown on a city lot, under crowded conditions and provided with only moderate care.

Several crosses have been made at Purdue with the Persian walnut, and approximately 100 seedlings have been distributed to various persons throughout a large area of the state. The trees do not seem as susceptible to insect and disease damage as the native black walnut, and growing well in sod should make good lawn trees. Some of the nut trees were sprayed with "Nu Green"—five pounds per 100 gallons of spray material was used on the orchard crops, and great growth response was noted for the sprayed over unsprayed trees. As the home owner is forever looking for new trees to plant, and trees with clean habits, the Persian and particularly the Carpathian selections may be the answer.

The speaker exhibited photographs to illustrate his talk. They pictured several of the different trees he had mentioned. The photographs showed the conditions under which the trees grew, the effects of fertilizing, and the injuries resulting from the winter cold. The reading of the paper was followed by a short discussion, after which Dr. Rohrbacher called upon Mr. Ira Kyhl, of Sabula, Iowa, who talked on the subject "Nut Growing in Eastern Iowa."