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Gardening Answers Knowledgebase

Plant Answer Line Question

Keywords: Brunnera, Stachys, Liriope, Epimedium, Lamium, Alpine and rock gardening, Shade gardening, Ground cover plants, Geranium

I'm looking to plant in a narrow strip on our retaining walls some "spiller" plants which will overhang the walls (which face north).

I'd prefer evergreen plants which would fill in fairly quickly, but I could also mix in slower-growing and deciduous plants. There's great drainage since I have gravel reservoirs behind each wall, and the part of the plant above the wall will get part to full sun, though I could overplant them if necessary for a plant that couldn't handle full sun.

I would like plants with interesting foliage and form to soften the look of the walls, and so would prefer a furry look to a spiny one. Flowers and fragrance are less important though always nice, and I'm hoping to have at least 2 or 3 different plant types with different colored foliage (shades of green are fine).


Some of the plants that occur to me, based on the description of your site, are Brunnera macrophylla, Epimedium, Geranium phaeum, Stachys byzantina, Lamium maculatum, and Liriope. Of these, the Geranium and Lamium will trail somewhat, while the others are essentially upright.

Graham Rice's article on the Royal Horticultural Society site features a selection of recommended trailing (or spilling) plants. Here is another good list of trailing plants for walls.

You could also try entering your site requirements into the plant-finding and plant selection web pages below:

Great Plant Picks (a local site)

King County's native plant guide

Missouri Botanic Garden Plant Finder

Royal Horticultural Society Plant Finder

The Miller Library has many books on gardening in the shade, so you may wish to come in and do some research to help you in your plant selection. Here is a booklist that may be of interest.

Date 2017-12-09
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Plant Answer Line Question

Keywords: Failure to flower, Stachys, Pruning shrubs, Leycesteria

I have a question about cutting back plants. I have some non-flowering lamb's ear that is looking quite scraggly. How far back do I cut these, and when?

Also, how far back should I cut my Himalayan honeysuckle? We planted it 2 years ago, and last summer it got 5 feet high!

Also, last year my Hebe plants did not flower. We have Hebe anomala purpurea 'Nana'. I have recently checked the tags they came with, and it doesn't mention that it flowers. Is this a non-flowering Hebe? Although the shrubs are lovely, I was hoping for the type that flowers. If we decide to move them, when would be the best time to transplant them?


Yes, Stachys (lamb's ears) can look pretty ragged after winter. I'm guessing you are growing Stachys byzantina 'Silver Carpet' or a similar cultivar, which doesn't flower. If you look closely, you should see signs of new growth. I would suggest cutting back all the tattered or dried leaves as far as you are able, without injuring new growth. March is a good time to divide the plant if you like. (I have shared this plant many times and moved clumps to new locations. It is quite tough, and will transplant easily.)

Himalayan honeysuckle, Leycesteria formosa, can be cut back to the ground (or within a few inches of the ground) in late winter or early spring,according to Sunset Western Garden Book. The website of Rainyside Gardeners (a Northwest site) has a useful page on Leycesteria formosa.

According to Hebes: A Guide to Species, Hybrids, and Allied Genera by Lawrie Metcalf (Timber Press, 2006), Hebe anomala 'Purpurea' is a synonym for Hebe odora 'Purpurea' which is supposed to have a lot of flowers. He doesn't mention the dwarf variety, 'Nana,' but I assume it would have similar attributes. Even with the nomenclature confusion, there seems to be some consensus about the floriferous qualities of the plant: Douglas Chalk's Hebes & Parahebes (Christopher Helm, 1988) lists Hebe 'Anomala' as a cultivar of Hebe odora, and he too says it has lots of flowers. Are your Hebes getting enough sun? Some Hebes will flower in partly shady sites, but the flowering will be diminished. Could they have been pruned accidentally, just before flowering? Another possibility is that the plants are not mature enough to flower. The Metcalf book mentions a few species which can take years to produce flowers. He also says that flowers are enhanced by chilling followed by warmth, over a period of about 12 weeks. The number of hours of daylight to which the plants are exposed is also a factor. As far as transplanting, doing it in March should be fine. It isn't too hot, and we are likely to have the occasional rain,but you should still water well when you first move them.

Date 2017-05-26
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May 31 2018 13:14:08