IRISH GARDENING 



VOLUME XV 



No. 174 



Editor— J- W. Besant. 



A MONTHLY JOURNAL DEVOTED TO THE 



ADVANCEMENT OF HORTICULTURE ANlf'^**'"^^'^^^'^ 



fw ¥•*< 1920 

 ARBORICULTURE IN IRELAND .V,.^ 



Plants for the Rock Gardener to avoids or to 



be careful about* 



If one is a really keen gardener it takes a lot to 

 damp one's enthusiasm, but there must be 

 something especially resilient in the constitu- 

 tion of the rock gardener which enables him to 

 come back with unimpaired enthusiasm to the 

 formation of his collection notwithstanding 

 the many occasions upon which his ignor- 

 ance has been imposed \ipon by those who 

 should have been his friendly advisers. For 

 it seems to be the almost invariable custom, 

 for the rock gardener of some ■experience to 

 dump upon the rock gardener of less experi- 

 ence all the ramping invasive weeds with 

 which he himself has struggled. It is quite 

 right that one should dissuade the inexperi- 

 enced from filling his garden at first with diffi- 

 cult plants like Eritrichiums and some of the 

 high alpine Violas, but it is almost criminal to 

 pass on to him without warning plants like 

 some of the Lmarias, with which he must 

 make unending warfare. I remember with the 

 deepest gratitude one of the few benefactors of 

 my garden wlio invariably gave me a warning 

 with a plant where one was necessary, and I 

 sometimes hope that a particularly warm spot 

 will be reserved hereafter for others who have 

 added unnecessarily to my labours. 



One has to deal with two types of pests — 

 (1) runners and (2) seeders. The first one the 

 worst. Amongst them, unfortunately, are a 

 few beautiful things that one must grow, but 

 others have not even the merit of beauty. 



The worst pest in my garden is possibly 

 Linaria pallida, quite a pretty toadflax with 

 large violet and white flowers, but it has tiny, 

 brittle, white, thready roots, which go any 

 depth and into any crack, and it is almost 

 impossible to get rid of it. I have d\ig out a 

 bed and thrown away the soil, but it still 

 appears, and if it once gets in among plants 

 that one fears to lift and move, one may give 

 up the contest as hopeless. Several other 

 Linarias are almost equally bad. L. hepaticcF- 

 folia has gone right tlirough a strong bank and 

 is spreading rapidly on the other side. Only 

 L. Hendcr>iOiii and L. orhjamjoVia so far seem 

 inclined to confine themselves to decent limits. 



It is always advisable to receive with 

 caution any plant described as an " ideal 

 carpeter " ; as a rule this implies that your 

 garden will soon be all carpet and no furniture. 

 Arenaria balearica is one of these; its close 

 mats of foliage strangle any small, choice thing 

 and it must be confined to actual rocks. Every 

 spring I cut strips of it back, leaving a few 

 inches of bare rock between it and any soil, 

 and by autumn it has recovered the rock and 

 is commencing to run over the soil, but this 

 plant is possibly the best dwarf carpeter for 

 stone, and its many white stars in spring are 

 indescribably beautiful. 



Helxine SuUcroIii is even more invasive, and 

 has no flowers. It makes a thicker mat of 

 bushy green that swamps everything in sum- 

 mer and dies away in du'ty brown patches in 

 winter. If it would only die away entirely I 

 would willingly pay for a tombstone, but it 

 doesn't; on the contrary, even the hardest 

 winter fails to kill some bit tucked away under 

 a stone or in the foliage of a mossy Saxifrage, 

 from wdaich it will surely spread t'he following 

 spring. 



The Aetenas are surface-rooters which can be 

 kept in check by constant pulling up, but one 

 must beware of their biuTs in autiunn, which 

 cling to one's clothes and get carried about 

 to seed themselves elsewhere. 



The Cotulas are also " carpeters " that I 

 could dispense with, particularly one well- 

 named sqiiaVnla and another .named potcn- 



Anfviuiiirld iVnuca must be ti'eated like 

 Acoena. Anonouc sijlvestris is also trouble- 

 some and it rarelv shows one a sufficient num- 

 ber of its beautiful white flowers to repay one 

 for finding a solid mass of its leaves appearing 

 yards away from whei'e one hoped to keep it. 



Among Campanulas, one must be careful 

 about C. coIVma : it is too beautiful to be ex- 

 cluded, but its foliage is strong and its roots 

 are stout and very overpowering, and no 

 ordinary sized rock will prevent it from spread- 

 ing to adjoining pockets. Almost equally ram- 

 pageous^whcn it succeeds — is C. puncfuta, 



