Chapter XXVI. — Garden Escapes
Included under the above heading are chiefly trees, shrubs, and hedge plants; escapes from the garden proper occur in lesser numbers. Some of them would, I believe, survive for considerable periods were mankind, fires, and domesticated beasts banished from the land; a few perhaps would take a permanent place in a reconstituted flora of New Zealand.
On Tutira the groves of golden willow (Salix alba), as well as fine specimen trees, owe their origin to a stout riding-switch brought at my request in '83 or '84 by Mr T. J. Stuart from Meanee. The original stick placed in a corner of our first garden unfortunately had to be destroyed on account of its great growth, but not before its limbs had been widely distributed over the run. Although so free a grower no seedlings appear: increase has been by stake, pole, or less often, by branchlets carried down in slips and floods.
White poplar (Populus alba) is another species which, although not reproducing itself by means of seed, yet merits inclusion amongst garden escapes. Planted in '85, it has of late years in a small way become a nuisance by reason of inordinate suckering.
Two or three score of pines (Pinus insignis and Pinus austriaca) were planted on Taupunga peninsula by Stuart and Kiernan in '80. Both species have in their immediate neighbourhood spread towards the south-east, their light flat seeds having been blown from ripe high-placed cones during north-western gales. In the lee of the original plantation a younger generation of each has arisen. Pinus insignis, in addition, has managed to convey itself great distances north, south, east, and west from its orginal site.
Individual pines of this species have appeared in localities so barren and miserable that sheep seldom graze over them; sheep nevertheless page 260 have, I think, been the transporting agency which alone can account for these cases of distant germination. Unless seed had found lodgment in a fleece and been thus carried far afield, it is hard to account for specimens discovered miles distant from the parent plantation. The insignis, as it is universally known in New Zealand, makes a double growth each season, one in spring, another in autumn; it is not surprising, therefore, that several of the trees planted forty years ago have attained a diameter of more than five feet.
A score of eucalypts (Eucalyptus globulus) were also planted by Stuart and Kiernan; though, however, the species has reproduced itself, the blue gum compared to the pine is but a sedentary plant. Only in spots where fire has swept over the ground, and but at limited distances from the parent trees, has germination occurred.
Prickly acacia (Robinia pseud-acacia) and wattle (Acacia deal-bata) perpetuate themselves not only by ample suckering, but also by seeds. I have found young plants of each on favourable sites several hundred yards from the homestead. Though I have never seen birds feeding on seeds of either of these plants, they oftenest appear in company of seedling gooseberries and blackberries, obviously dropped from roosting-boughs.
The original elderberry (Sambucus nigra) growing on Tutira had also been on my suggestion brought up as a riding-stick. Although the small thicket grown from this riding-switch has been destroyed, yet the plant has managed by means of seed to migrate a distance of a couple of miles.
Of broom (Cytisus scoparius), a single plant grew for over twenty years on the site of an old clearing on Putorino. Owing to ploughing, of late years it has largely increased.
Gorse (Ulex europœus) had also preceded me. On Tutira there have always been half a dozen patches, spread possibly by horses, possibly by pig, in very early days from a hedge which partly enclosed a native cultivation-ground near Lake Orakai. No new thicket has appeared in my time, although the original patches have increased in size through ill-advised attempts to destroy them by fire.
African box-thorn (Lucium horridum) and barberry (Berberis vulgaris) have each been used as hedge plants; each has spread not only about the policies but to the distance of several hundred yards by means of seedlings, all of which I may add have been destroyed.page 261
In 1914 seed from a honeysuckle hedge (Lonicera japonica) had germinated beneath a favourite roosting-place of minahs. The young plants had found a suitable nidus in the shade and leaf-mould of a long-established cherry grove. When, after the war, I returned, the little thicket had been smothered, macrocarp and barberry hedges about the homestead had likewise been overrun; honeysuckle had also established itself everywhere in the plantations and manuka gullies reserved for native birds.
The strawberry (Fragaria elatior), planted during '78 or '79 in a temporary garden on the Taupunga peninsula, was nearly thirty years later still surviving. It had been growing in turf,—turf, moreover, except for a few weeks in each year, perpetually nibbled by sheep. Proximity of scrub may have prevented stock biting very closely herbage rather less palatable on that account, otherwise this highly valued garden plant had endured for over a quarter of a century the hardships of the commonest weed. Moved to a somewhat neglected corner of a later garden, the transplanted roots have taken a new lease of life and appear determined to maintain their grip on the station both by seed and runner; but though vigour has revived, flavour has altogether gone. Grown again with full exposure to the sun, the fruit of these rescued strawberries is extraordinarily tasteless—literally is not worth the labour of gathering.1
When it is considered how in the animal kingdom some long-domesticated species are unable, or hardly able, like the camel, to reproduce their kind and maintain themselves without the assistance of man, the sustained vitality of many of our domesticated plants appears remarkable. It would have seemed more probable that after centuries of rich feeding, culture, and care, the stamina of such plants would have become impaired, or at any rate modified to meet these artificial conditions. Yet the strawberry, gooseberry, parsnip, tansy, horse-radish, carrot, and potato appear after centuries of care to have retained the pristine virility of their wild progenitors.
Comment has already been made on the hardihood and virility of the garden strawberry; the long persistence of the potato (Solanum tuberosum) seems as remarkable; that such a plant, manured and carefully page 262 tended by man for hundreds of years, should endure, as it has done on Tutira for more than half a century, an entire absence of tillage, the strangulation of matted turf, the trampling of stock, the competition of cherry-suckers and the shade of trees, has always been a matter of surprise to me. Yet in 1906 I gathered tubers, healthy though deteriorated in size to big peas, from native cultivation-grounds deserted for fifty years. Very carefully disentangled from turf and replanted with fibrous roots undamaged, these peas produced that same season potatoes as large as damsons. Next year I had a profusion of well-grown tubers, blue-skinned and blue also throughout the flesh. Though of no great size, they possessed the peculiar flavour of the plant in a marked degree; in taste they were superior to the more shapely field and garden varieties of modern times.
Carrot (Daucus carota) grows sparsely though vigorously in some of the homestead clover - paddocks. Parsnip (Peucedanum sativum) and horse-radish (Cochlearia armoracia) maintain themselves, in spite of weeding, chipping, and digging, on the site of the original garden of 1884. The former has also in light lands persisted for years on the site of a deserted drover's camp, having probably arrived there as seed in sacking.
Though here and there in the district the vine (Vitis vinifera) still flourishes, it cannot be considered truly a garden escape. As, however, a solitary specimen on Tutira has survived for half a century on the site of George Bee's deserted garden near the foot of the zigzag on the Heru-o-Tureia block, I include it in our list. Another grows on the banks of the Waikoau, midway between the eastern ford of that river and the coast. The vine, I believe, never in Hawke's Bay renews itself by seed, though raisin stones, accidentally reaching dry soils, germinate freely.
Tansy (Tanacetum vulgare), not even now to be found as a potherb in the station garden, grows but on one spot on Tutira. As its arrival illustrates what must occur in the way of combination of favourable chances before a new species can appear in a new locality, as also the plant is one about whose manner of travel there can be almost no doubt whatever, it deserves the distinction of a paragraph.
As remnants of conquered races take refuge in the mountains, so amongst rocks do persecuted plants longest survive. Cape-gooseberry (Physalis peruviana) still manages to hold out precariously in the crannies of certain limestone cliffs. The only plant of tobacco (Nicotiana tabaccum) got by me on Tutira was procured as far back as '83, also beyond the reach of stock, on one of the huge limestone quadrilaterals of the Racecourse paddock. Each of these plants had doubtless escaped from native cultivations in very early times.
Of the species included in this chapter, few have spread beyond a couple of miles, whilst several survive only by suckering or the carriage of broken branchlets in floods and landslips. Six years ago it would have been correct to say that asparagus, elderberry, box-thorn, barberry, gooseberry, raspberry, red-currant, and honeysuckle had strayed but a score or so yards from garden and orchard. That is no longer the case. Alien birds are year by year proving more active agents in the dissemination of alien vegetation, The blackbird, thrush, and minah especially are becoming more and more parasitic to garden and orchard; by them seeds are being carried season by season further afield.
1 It may be worth adding, in view of the open question as to the relative flavour of British and New Zealand small fruit, that the taste of another variety of strawberry grown in the Tutira garden seems to me to be excellent. I believe, too, that our station rasps, gooseberries, and currants are as full-flavoured as those grown in England.