PLSC 368: Plant Propagation
February 18, 2004
Lab Exercise 5

5. PLANT PROPAGATION BY HARDWOOD EVERGREEN CUTTINGS

Note: In this lab exercise, you will learn procedures for propagating hardwood evergreen trees and shrubs by cutting. Work in a group of two or three students. Turn in the lab report on April 28, 2004.

A. Introduction

        The rootability of evergreen cuttings is greatly dependent on the species involved. Most varieties of junipers, arborvitae, taxus, and boxwood root quite readily. Pine, spruce, and fir are readily grown from seed. However, in the interest of perpetuating specific forms, color, hardiness, etc., these species can and are propagated asexually. Although grafting is a common method of propagating pine, fir, and spruce, they can also be grown from cuttings.
        In general, cuttings are taken during late fall and during the winter. This, however, varies greatly and the literature should be checked for specific times for each species as in some instances, a month's difference in collection time will result in success or failure. One notable exception to the fall or winter collection is Mugo pine which roots best from cuttings taken in June, just as the candles unfold their needles. Evergreen cuttings are made from the current year's wood excluding the tender, soft tip of each branch. The cuttings should be 5-7 inches long with the lower needles removed from that portion of the stem which is inserted into the media.
        In most cases, it is beneficial to treat evergreen cuttings with a rooting hormone. The hormone to use, and its concentrations is dependent on species and variety. Mugo pine is again a good example wherein hormone treatment may be beneficial to some clones and detrimental to others. Bottom heat (65-75 oF) is usually required. Although a high humidity must be maintained during rooting, a mist system is not essential.
        Broad-leaf evergreen cuttings, including boxwood, holly, ivy, myrtle, spurge, gardenia, rhododendron, camellia, etc., may be rooted from current year cuttings taken from late summer to early winter. Procedures are similar to those suggested for narrow-leaf evergreens. The purposes of these experiments are:
            a. To learn the techniques of propagating hardwood evergreen cuttings.
            b. To determine the influence of rooting media and growth regulators on the rooting of hardwood evergreen cuttings.

B. Procedures

           Plant Materials:
                    1. Juniperus horizontalis 'Blue Chip' (Blue Chip Juniper)
                    2. Juniperus chinensis 'Mint Julep' (Mint Julep Juniper
                    3. Thuja occidentalis (Globe Form Arborvitae)
                    4. Thuja occidentalis (Pyramidal Form Arborvitae)

  A. Influence of media on rooting of cuttings.
          1. Prepare 40 cuttings from each of 2 species of the plant materials available as demonstrated. Dip into 0.8% of IBA.
          2. Stick 10 cuttings of each species in each of the 4 rooting media.
              a. Peat
              b. 50% peat and 50% perlite
              c. 50% perlite and 50% vermiculite
              d. Perlite
          3. Make observations of cuttings at 2 week intervals for signs of callusing and eventual rooting.
            B. Influence of growth regulator treatment on rooting of cuttings.
                    1. Prepare 100 cuttings from one species of your choice.
                    2. Treat the cuttings with the following growth regulator series:
                          a. (1) Control - no hormone               b.(1) Control - no hormone
                              (2) IBA 0.1% (powder)                    (2) IBA 100 ppm
                              (3) IBA 0.3%                                   (3) IBA 1,000 ppm
                              (4) IBA 0.8%                                   (4) IBA 2,000 ppm
                              (5) IBA 1.6%                                   (5) IBA 4,000 ppm
3. Stick the cuttings into the rooting medium containing 50% peat and 50% perlite.
4. Make observations of cuttings for signs of callusing and eventual rooting as before.
C. Data
Score the rooting (% rooting, number roots/cutting) in each treatment. Average the scores and discuss the outcome of your experiment. Write a lab report summarizing your data.
D. Lab Report
          Write a report, using the following format:
a. Title and your name
b. Abstract
    (A brief summary of findings)
c. Introduction
    (One or two paragraphs; importance and objectives of the experiment)
d. Materials and Methods
    (Plant, soil and other materials used; how the experiment was run)
e. Results and Discussion
    (Data on rooting percentages and their comparisons)
    (Discussions and comments on your findings)
f. References
    (List literature if cited)
 
             Table 1. Effect of plant age on rooting of selected evergreen cuttings. It was found by chance
             that cuttings of apple taken from one-year-old seedlings rooted very readily. Comparisons of different
             aged plants were then made with other species. Some of the results were as follows:
Species
Percent Rooting
1yr  2yr  3yr  Older
Llex opaca (American Holly) 100 64 47 0
Pinus sylvestris (Scotch Pine) 77 8 0  
Pinus strobus (White Pine) 98 51 12  
Pinus resinosa (Red Pine) 62 3 7  
Pinus taeda (Loblolly Pine) 46 6 0  
Thuja occidentalis (American Arborvitae)   100 42  
Picea excelsa (Norway Spruce)   90   50
Taxodium distichum (Bald Cypress) 95 30 10  
    Source: Gardner, F.E. 1930. The relationship between tree age and the rooting of cuttings.
                Proc. Amer. Soc. Hort. Sci 26:101-104.


            Table 2. A condensed summary of cutting propagation schedule for selected woody evergreens.

Plant
N
Rooting time (wk)
Remarks
Broadleaf Evergreens                            
Abelia             x xx xx xx     4-6  
Berberis                 xx xx xx   5-7  
Buxus semp. suff.               xx xx       5-8  
Buxus, all other                 xx xx xx   5-8  
Contoneaster               xx xx xx xx   4-6  
Eleagnus                 xx xx xx   5-7  
Euonymus fortunei xx xx xx         xx xx xx xx xx 3-4  
Euonymus sieboldiana (ManhattanF1)             xx xx xx xx xx xx 3-4 Filler crop (root anytime)
Ilex crenata, glabra               x xx xx x   5-8  
Ilex fosteria, opaca                 x xx xx   8-10  
Mahonia                   x xx   6-8 Frost essential
Pyracantha                 xx xx xx   4-6  
Sarcococca h. humilis                 xx xx xx xx 6-8  
Stranvaesia d. undulata                 xx xx xx   6-8  
Viburnum rhytidophyllum                     xx xx 5-7  
Yucca xx                   xx xx 10-14 Root cuttings
Coniferous Evergreens                            
Chamaecyparis nootkatensis                   xx xx xx 8-12  
Chamaecyparis obtusa                   x xx xx 10-12  
Cryptomeria japonica     xx                   8-10  
Juniperus chinensis, upright                     xx xx 10-12  
Juniperus chin., spreading xx                   xx xx 10-14  
Juniperus chinensis, sargenti xx xx                 xx xx 8-10  
Juniperus horizontalis xx xx               xx xx xx 8-10  
Juniperus virginiana                   xx xx xx 8-14  
Taxus baccata                   xx xx xx 10-14  
Taxus cusp., media xx                 xx xx xx 10-14  
Thuja occid., upright xx xx                 xx xx 8-12  
Thuja occidentalis, umbrac. xx xx xx                 xx 6-10  
Thuja occid., woodwardi xx xx xx                 xx 6-10  
Tsuga canadensis xx xx                   xx 10-12  

 

            ROOTING RESULTS OF CUTTINGEXPERIMENTS



            Plantspecies___________________
            Date examined_________________
 

Treatment Total number Number 
dead
Number
callused;
not Rooted
Number alive 
not callused
or rooted
Number
with
roots
%
rooting 
Average
number
of roots
Average
length
of roots
Visual
injury
% of roots
Visual
quality
rating
Comments
                       
                       
                       
                       
                       
                       
                       
                       
                       
                       
                       
                       
                       
                       
                       
                       
                       
                       
                       
                       
                       
                       
                       
                       


Cutting Propagation Lab 2
Evergreen Cuttings

PREPARATIONS NEEDED

1. Plant Materials
1. Juniperus horizontalis 'Blue Chip' (Blue Chip Juniper)
2. Juniperus chinensis 'Mint Julep' (Mint Julep Juniper)
3. Thuja occidentalis 'Techny' (Techny Arborvitae)
4. Thuja occidentalis 'Woodwardii' (Woodward Globe Arborvitae)
5. Thuja occidentalis 'Wareana' (Siberian Arborvitae)
2. Growth Regulators
1) Commercial rooting powders
    Check the shelves in the greenhouse lab.
2) IBA solutions
    Prepare IBA solutions (in 50% ethanol) in 300 ml bottles
    (Dissolve IBA in 100% ethanol, and then dilute to 50%)
3) NAA solutions
    Prepare NAA solutions in ethanol or NaOH, then dilute with water.
4) Also prepare control (water) solutions.
    All growth regulator solutions must be kept in brown bottles or wrapped in aluminum foils. Store the bottles
    in the refrigerator until use.
5) Buy or get about 50 styrofoam cups to small aliquots of growth regulator solutions during the lab period.
3. Supplies and Tools
1) Pruning shears (13 pairs)
2) Plastic labels (one box)
3) Sharpee pens (5-6, or a box)
4) Rooting medium
    A 50% perlite: 50% peat mixture (about 2 ft3)
5) Trays and cell packs
    About 20 trays and 20 cell pack trays.
6) Other supplies: paper towels, etc.