Junipers are evergreen and come in all shapes, sizes and colours, they are also very hardy, surviving -20⁰C and grow well in a wide range of garden soils. They are traditionally planted with heathers, rhododendrons, acers and other “dwarf” conifers. The forms I am writing about today make good weed supressing ground-cover as they tend to grow horizontally rather than vertically many to no more than 50cm tall and 1.5m wide. Although I will refrain from overuse of botanical Latin names, which can be difficult for the non or rare user to get their tongue around, it is a necessary evil for accurate identification of forms. With junipers, to impress your friends with your botanical Latin, all you need to do is add “us” to the end of juniper making Juniperus. Latin plant names are always written in italics.
As weed supressing ground-cover low growing junipers are excellent, as long as the area they are to be planted in has been well cleared of perennial weed roots. If not properly removed these weeds can grow back and become an ongoing and difficult to eradicate nuisance spoiling the look of a planting.
Being evergreen Junipers contribute winter colour and form to the garden. Some of the ground-cover forms like J. communis. ’Repanda’ and J. squamata ‘ Blue Carpet’ can be difficult to combine with bulbs as you would need a tall bulb to push through which looks fine when the bulb is in flower but after flowering the dying foliage hanging over the spiky juniper foliage can look unsightly. I have successfully planted small cultivars of Iris reticulata species with Juniperus communis ‘Goldschatz’. This juniper only grows to around 10cm tall and the foliage of small irises are less noticeable after flowering as they die back quicker and can be removed sooner if wished.
This week I planted a recently purchased Juniperus c. ’Repanda’ at the edge of a stepping stone path leading to a garden bench. Looking to choose a complimentary companion plant as its neighbour and not wanting to go down the more usually associated heather / dwarf conifer route I have chosen a woodlander from my garden called red barrenwort, Epimedium X rubrum . Sorry more Latin. It grows to a similar height and has heart shaped glossy green leaves with a hint of red running through it which I think balances and compliments the spiky needle leaves of the juniper. It is also long lived and similar sized at maturity. Epimediums produce tiny flowers in spring but their primary ornamental value is their interesting leaf shapes and colours. The clump I lifted was large enough for me to chop up into three pieces before replanting which will speed up the re- establishment process. Thoroughly soaking plants by letting them sit in a water filled container before planting aids establishment.
Being a deciduous herbaceous perennial epimedium foliage dies down in the winter which will allow me to plant some early flowering bulbs amongst the clumps. I have a passion for iris bulb species, they do well in my garden without spreading too quickly. They should happily share the location with the epimediums and provide early colour before the epimediums leaves emerge later in the spring. Although it is not necessary, cutting the dying foliage down after the winter is said to improve the following year’s foliage display.
I have also added a layer of natural wood fibre from a bag of Gro-Sure Smart Groundcover from Westland horticulture initially brought to my attention by one of my customers. Westland claims it acts as a moisture retaining and weed supressing mulch. This for me is a little trial to see how effective it is. Wood fibre is made from wood chips which have been ground down further by grinding between steel plates until they form fine intertwining fibres.
It is the same material as many insulation products are made from and is used in large scale erosion control. With additional treatments it is used to make firm products such as plywood so I have no doubts that as the bag states it can last a long time, be used on slopes and form a solid enough barrier to prevent weeds emerging. My concern is the claim that it does not hinder bulbs emerging. This could occur not only because of the tight locking process of the cellulose fibre but also like bark , unless it has been allowed to age for around six months, many trees used to produce these products contain toxins which can inhibit the growth and kill young plants. I am sure it is fine as a general ground-cover on established mature plants and large or vigorous spreading bulbs but finer bulbs and corms such as cyclamen may not penetrate the tightly locking fibres.