for November, 1920 



371 



Protecting Tender Garden Subjects 



HENRY J. MOORE 



WITH the advent of early Winter, naturally the 

 grower of semi-hardy herbaceous and other 

 plants becomes much concerned as to the 

 method to be employed in protecting these from the 

 Winter's cold. Sometimes over anxiety for their safe- 

 ty leads him to apply the mulch or protective material 

 too thickly, with the result that many of the subjects 

 are smothered. Sometimes he is too careless and 

 applies too little, and consequently the subjects freeze. 



In order to successfully protect the tender plants, 

 there are certain simple but essential things to learn. 

 When we make a study of the way in which Xature 

 protects the dormant subjects during Winter, we find 

 that the straws, leaves and twigs are usually blown in 

 and around the plants and lodge very lightly. Even 

 the leaves and stems of herbaceous subjects fall light- 

 ly over the roots which produced them. These pro- 

 tective materials, when covered with snow, usually 

 afford adequate protection during the coldest months. 



What does Xature teach us by the forementioned 

 simple illustration? That the Winter's mulch she ap- 

 plies is composed of coarse but light materials throtigh 

 which air may pass. Thus, when we apply a mulch to 

 our herbaceous borders, or to beds, or plots of tender 

 subjects, we must see that a proper material is chosen 

 and properly applied, so as not to preclude the en- 

 trance or exit of air. 



Perhaps the greatest mistake is made by applying 

 well rotted stable manure to serve as a protective 

 mulch. While this may suffice in the case of many- 

 subjects, generally the practice is wrong. 'W'hen satu- 

 rated with moisture the manure settles down into a 

 dense soggy mass throtigh which air cannot readily 

 pass, if at all, as the spaces between the fibres are filled 

 with water to the exclusion of air. 'Well rotted stable 

 manure may be advantageously applied to a host of 

 hardy well rooted subjects as a mantire, and in fact 

 this is generally practiced during the Fall, but we 

 must realize that there is a vast difference between 

 a manure and a protective mulch. 



Strawy litter shaken out from the manure pile, or 

 this mixed with leaves, or even leaves which have been 

 piled away for one year are themselves good for use 

 to protect the tender plants of our borders. These 

 should be spread over the border to a depth of about 

 four inches, or over the roots of individual subjects 

 as the case may be. Between the fibres of this coarse 

 material there are air spaces which will always be 

 filled with air. This film or cushion of air acts as a 

 buffer to the cold ou'ter air, preventing its too rapid 

 entrance and to the relatively warmer air, preventing 

 its too rapid exit from beneath the mulch. Thus a 

 slow and gradual but nevertheless sure interchange of 

 air takes place. The outer air is warmed in entering, 

 the inner air does not leave too rapidly, and conse- 

 quently the plants are not chilled bv sudden changes 

 of temperature. 



A soil in which there is a circulation of air is usuallv 

 warmer, and certainly is drier than one in which little 

 circulation takes place. A heavy dressing of rotted 

 manure precludes the entrance of air, and when once 

 wet will keep the soil in a wet condition as long as the 

 manure itself holds the moisture. 'When such a soil 



freezes it becomes almost a solid mass of ice. A soil 

 covered with a coarse protective mulch is usually drier, 

 as the mulch above it does not hold water, but air. 

 Such a soil when in a frozen condition is usually more 

 or less ''honeycombed," most of the spaces being 

 only partially filled with ice, thus favoring aeration. 



No matter what materials are used for our purpose, 

 the protective mulch should not be applied before the 

 ground is lightly and, if possible, permanently encrust- 

 ed by frost. By this time much of the moisture may 

 have escaped, and when the Winter's covering is ap- 

 plied the tender subjects will enjoy a warmer and 

 drier habitation through the cold months. To apply 

 the mulch earlier than this may result in injury. If 

 after applying it a warm or rainy spell should occur, 

 the extra protection will tend to make the plants less 

 hardy and less able to withstand the Winter, and in 

 some cases to actually start prematurely into growth, 

 — we must not cover up our plants too early. 



The principle outlined above will also apply to tender 

 plants whose stems and leaves remain green through 

 Winter, and which depend upon these for the flowers 

 of the coming season. Let us take Canterbury Bells 

 as an example. When protecting these, it is only- a 

 case of applying the material in a slightly dift'erent 

 manner, as it is not the roots which will freeze, but 

 the tops, therefore these must be protected. It will, 

 however, be obvious that a heavy laj'er of mulch will 

 have a tendency to break the stems and leaves. Once 

 broken thev quickh- decay and often the plant:? will 

 damp completely off. The more impervious to air the 

 mulch, the greater the danger of damping. 



If a few small branches of trees ctit to a length of 

 about eighteen inches are stuck in the ground, about 

 the same distance apart, throughout the area contain- 

 ing the plants, and the protective material is placed 

 lightly over these, they will prevent it from pressing 

 down upon the subjects unduly. Stifficient air will 

 pass through the covering for the needs of the plants 

 (for plants require air in Winter as well as Summer). 

 The covering will remain much drier when partially- 

 suspended on the branches, than were it on the ground, 

 and the danger of damping be largely obviated. 



Tender shrubs, such as Roses of many kinds, may 

 be protected by simply scattering strawv litter light- 

 ly around the roots, or by tying straw around the 

 stems. The grower, however, should not attempt a 

 too elaborate operation when protecting these, or in 

 fact any tender subjects. .Any method of protection 

 which tends to exclude pure air is wrong, any which 

 favors a gradual interchange of air is right. Certain 

 parts of ])lants must "breathe." Even the soil must 

 Iircathe — the gases of fermentation must escape. It must 

 1)e aerated or it cannot be healthy, and as an aerated soil 

 is warmer than an unaerated one plants are more likely 

 to winter succesfully tmdcr the former condition. 



The writer will leave the reader to answer the ques- 

 tion he now asks. The more the reader ponders over 

 it, the greater will be the benefit derived from this 

 article. Why is the hand in a woolen glove through 

 which the air can pass, warmer on a zero day than 

 one encased in a kid glove, which is practically imper- 

 vious to air? 



