Documents: Container & Small Space Gardening:

The Readers Write About Ponds, Ground Covers And Deciduous Barberries
by Art Drysdale
by Art Drysdale


Art Drysdale, a life-long resident of Toronto and a horticulturist well known all across Canada, is now a resident of Parksville, British Columbia on Vancouver Island, just north of Nanaimo. He has reno-vated an old home and has a new garden there. His radio gardening vignettes are heard in south-western Ontario over radio station Easy 101 FM out of Tillsonburg at 2 PM weekdays.

Art also has his own website at

February 11, 2001

Epimedium.jpg (86781 bytes)
Barrenwort (Epimedium grandiflorum) is just one excellent ground-cover plant that should be much more used. It grows well in partly shaded, dry conditions, and even competes well with tree roots. The leaves start out bright green with a slight tinge of pink or red, later they turn a deeper green and the veining shows well, by autumn they take on yellow to bronze tones. White, pink, violet or even yellow-spurred flowers about 2 cm long appear in June.
Author photo.

Several weeks ago Pat McAlister of Durham, Ontario wrote and asked two excellent questions pertaining to a pre-existing spring feed pond that they had enlarged to approximately 38 x 105 m (125 x 350’). It is apparently 1.5 m (5’) deep, and has one small island. The first question was “Are there any pond type plants that would aid in keeping the pond clean?” I responded that keeping a pond clean is a rather large topic, but in answer to her specific question, yes, all oxygenating plants (of which some such as Sagittaria natans are tropical, i.e. don't live over the winter, and some like the native Elodea canadensis are hardy) will help with this chore. So to will chemicals such as Pond Morena and Pond Peat (a sphagnum peat moss product in a net bags that are placed in the pond) both from the Sera company in Scarborough, Ontario. Sera products are well distributed across the country particularly at better garden centres that feature water garden plants and supplies.
In view of the size of the pond, another consideration, if the pond ever gets very low in water, or if it is possible to lower the water level drastically, would be to apply a very heavy gumbo clay layer to the bottom and tamp it down to form a natural clay liner. I have seen this done very effectively on large ponds such as at The Niagara Parks Commission Botanical Garden and School of Horticulture.
With regard to oxygenating plants, I suggested she try the people at Moore Water Gardens in Port Stanley first. They have the largest collection, and have been in this business longer than anyone else certainly in eastern Canada. (Humber Nurseries too has a good selection.) Still another method of keeping the pond clean (a minor item in such a large pond) is by the addition of trap door snails in copious numbers. These are scavengers that live over winters and really clean up algae particularly. You may e-mail Moore Water Gardens at
An additional suggestion I should have made to Pat was that she contact the newly formed Ontario Water Garden Society (e-mail: They have a newsletter and regular meetings and may just have a member who can offer first-hand advice on this specific topic.
Pat’s second question was to do with “The area around the sandy beach is extremely rocky and the soil is somewhat sandy and somewhat clay-based. Could you suggest an economical perennial ground cover that would not need cutting with the lawn tractor--as we already have a large area of lawn?”
Numerous perennials and other relatively low-priced plants will satisfy your specifications for the sandy area. I would suggest you go to a good garden centre (such as Humber Nurseries in Brampton, on old Hwy. 50, just south of Hwy. 7, west of Hwy. 427 and north of Hwy. 407. They would have at least 40 different such plants, and with many there are numerous cultivars.
Examples would be: Canada wild ginger (Asarum canadense) [now particularly popular with native plant advocates], bearberry (Arctostaphylos spp.) [shade, and only if soil is acid!], bugle flower (Ajuga spp.) [a number of quite different cultivars are available with varying leaf colours], goutweed (Aegopodium podograria 'Variegatum') [NB, very aggressive, weedy but great when in some shade and able to be confined], dwarf lady's mantle (Alchemilla erthropoda) [a smaller version of this popular perennial], lily-of-the-valley (Convallaria majalis) [excellent if there is some shade], snow-in-summer (Cerastium) [white flowers for a short period in spring, but silver foliage all season, very aggressive, for full sun], barrenwart (Epimedium grandiflorum) [particularly good in dry shade, even under trees]; sweet woodruff (Galium {Asperula} odoratum) [aggressive, pretty, tiny white flowers and small foliage for part shade], lamium dead nettle (Lamium maculatum ‘White Nancy’) [green foliage has abundant silver blotches making leaves look silver, white flowers May to July, good in shade or sun], yellow archangel (Lamiastrum galeabdolen) [yellow flowers and leaves marked with silver, a fast grower, sun and part shade], Sedum [many different ones with different colours of foliage and flowers, excellent in dry sunny locations], and germander (Teucrium chamaedrys) [basically evergreen foliage that turns purple for the winter, for sunny areas].
I personally would buy a couple or three of at least a half dozen different ones, and try them in the area(s) you want to cover. Then the next year, or even better, two years later, you could evaluate which ones were doing the best and plant those in large numbers. Note that spacing varies depending on the plant, but 30 cm (1’) apart is a good average.
More recently, Paul Nowosiadly wrote re availability of red-leaved barberry shrubs (he particularly likes red foliage shrubs and grows many different ones), and told me that someone in B.C. had advised they were for sale there. He had posted his question on the site and had several varying responses.
My suggestion was that he go to my website ( and look up the Commentaries page. There he will find, so far, only two, but one of them is on this topic. While it was written about ten months ago, it is still correct, except that the feds have not moved as fast as we thought they might (what else is new) and the date the new deciduous barberries will be available remains a question! The respondent from B.C. is no doubt correct, the old varieties (such as the absolutely delightful dwarf ‘Crimson Pygmy’ (Berberis thunbergii ‘Crimson Pygmy’--one of my favourite hedge plants) are being propagated and sold by a number of smaller nurseries across the country. That is not news, but it is illegal! Though it was advanced that it would be illegal to keep these plants in our gardens, that was never pursued, and it is not illegal to grow the deciduous Japanese barberries--just illegal to propagate or sell them in Canada. Read the Commentary if you want more background on this ridiculous regulation!

Art C. Drysdale, 6 Nesbitt Drive, Toronto, Ontario M4W 2G3

Art Drysdale is horticultural editor of Canada's oldest and fastest growing national gardening magazine, Plant & Garden. He is heard Saturdays from 8 to 9 AM, with a live radio broadcast on Toronto's powerful and clear, AM740 CHWO Primetime Radio.

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