Senna hebecarpa is rarely grown in gardens but it deserves to be used more frequently. It is a perennial that can grow to 180 cm (six feet) and has unusual compound leaves. Both of these features make it look more like a shrub.
Common names include American senna, wild senna and the northern wild senna. It is a North American legume, that hosts nitrogen fixing bacteria in it’s root nodules.
The last plant to start flowering in my zone 5 garden is Allium thunbergii ‘Ozawa’, the Japanese onion. As I write this it is October 26, 2014 and we have not had a real hard frost yet which is very unusual. Most common fall flowering plants like mums are finished flowering but the Japanese onion is still going strong. It is not bothered by early frost or snow.
Dictamnus albus, the gas plant, always makes a big splash in the garden when it is flowering and even when it is not flowering it is a very interesting plant with good leaf structure. Even the star-shaped seed heads are interesting. So why is this plant not seen more in gardens? It is very slow growing and I think it costs nurseries too much to get it to a saleable size. Fashions have also changed and this fantastic plant has been left behind in favor of more modern plants. That is a real shame since few garden plants will match the presence of a mature Dictamnus.
Arisaema thunbergii ssp. urashima is a great aroid that adds some excitement to the garden. Known as the dominatrix jack-in-the-pulpit, it appears in late spring and is gone by late summer. Its special feature is a long, dark purple, whip-like spadix that can reach 45 cm long, in true dominatrix fashion.
Corydalis solida is a great spring ephemeral that brings an unusual color to the garden at this time of year. How many of our spring flowers are red, pink or purplish red? Spread them around the garden between larger plants and enjoy them while the larger plants are still sleeping. By the time they grow to any size, C. solida will have gone underground for a summer snooze.
Allium fistulosum is a perennial onion that is good to eat and makes a great garden plant. It has many common names but the most common are welsh onion or Japanese bunching onion. “Welsh” is a corruption of the German “Walsch,” meaning “foreign,” and has no reference to Wales.
Primulas are great garden plants for part shade and Primula elatior ssp pallasii is one of the best. I normally do not care for pale colored flowers, but the light yellow of this one, combined with its early flowering, makes it stand out in the garden. It is a real gem that seems easy to grow.
It is difficult to find plants for dry shade but Pachysandra procumbens will be quite happy in such conditions, at least in cooler climates. In warm areas you might need to provide more moisture.
Pulsatilla are great rock garden plants and any species or cultivar will make a good addition to your garden. They all flower early, and then produce lovely hairy seed heads. Pulsatilla styriaca is one of the earliest pulsatilla to bloom.
Yucca glauca, an agave, is the hardiest yucca growing from Alberta, Canada all the way to Texas. You will either love or hate this plant depending on your appetite for desert-like plants. I love them for their spiky leaves and fantastic flowers. They are extremely drought tolerant and easy to grow.
Paeonia rockii is a lovely tree peony that should be grown more. It can be difficult to find in a nursery, but those specializing in peonies will have it. The ones pictured here were grown from seed obtained from the Ontario Rock Garden Society Seedex program. The flowers are mostly white or light pink with dark maroon basal flares on the petals. There is some variation in flower form and coloration. One seedling from this group has red leaves in early summer.
The common name, tree peony, describes the woody stems that are produced, but it is probably more correct to call these shrubs, not trees. They do not need staking.
Mention lamium to most gardeners and they run for the hills. Some lamium spread so fast they are thugs in the garden. Others, like L. maculatum, spread but can be controlled. A few are excellent, well behaved, garden plants and this includes Lamium orvala, which forms a nice non-spreading clump. It might seed around a bit, but it is easily pulled out if you get too many.