So you have started to delve into native plants and now you are thinking, "What kind of plants can I have in my understory (layer between ground plants and tall canopy trees) that will give me structure, provide pretty flowers that are fragrant, and might have a very beautiful texture?"
Welcome, you've come to the right place! After establishing a native plant garden for over 15 years, I have experimented with shrubs tiny, medium, and tall! And of course, what makes a shrub and a small tree is a very fine line and to some degree, I am talking about both; small trees, and big shrubs, and of course smaller woody plants, which we call shrubs! More specifically, some plants are herbaceous, meaning they have soft, non-woody tissue and they are either an annual (growing from a seed) or perennial (growing from roots each year). A shrub is a smallish (up to the size of a small tree, maximum 10’ tall) woody plant that exists throughout the seasons.
Shrubs are interesting ‘tools’ and often ‘pieces of art’ in a garden in that they can represent the ‘in between,’ the focus, or both. In between the top and bottom heights. In between the small (ground layer plants) and the large (canopy trees). The focus; a beautiful intricate creation unto itself. Design wise, they can be used to ‘create the space between the notes…and speaking of notes, shrubs can be great perching or even nesting spots for birds that sing beautiful songs, adding another sensory element to your garden that the plants (unless you had a synthesizer hooked up to their roots and shoots) cannot offer. Shrubs can be cover over which rabbits nest, or toads, in transit, can stop and fashion an abode. Contrast wise, shrubs can help you create areas of light and dark by the shading they may provide, which often helps the mind calm and focus on areas you are wishing to highlight. Further, monoculture hedges can be replaced by a series of shrubs of different varieties, providing differing functions for wildlife, privacy or whatever is desired.
Famous (among botanists/ecologists) small trees/ shrubs in the wilds of the province are awe inspiring, from the gnarled and dwarfed E. White Cedar Trees estimated in excess of 1,000 years old growing on the Niagara Escarpment, to the Dwarf Hackberry Trees (barely taller than 10 feet) estimated about 400 years old growing on a shallow sandy ridge on Pelee Island. These rarities are not for the yard. They need to be kept in the wild of course but can really serve to fuel our creativity in the garden.
So let's look where we can start.... and let's start... really small. Tiny shrubs in my opinion are beauties to behold. Most of us have relatively small garden spaces and a 10’ x 10’ (1 x 1m) shrub takes up a lot of space! One species that jumps to mind quickly is Fly Honeysuckle. So many people purchase Japanese or other non-native Honeysuckles, which are quite detrimental to the environment because they produce berries that are eaten by our birds and then spread throughout our natural areas by bird droppings. Fly honeysuckle, if you can get your hands on one, is a shrub that rarely rises above a metre (3’) tall. It's beautiful with dainty little leaves and even dainty-er little yellowish flowers that hang and light up with the least amounts of sunlight.
Another one that I've seen so often in nature but one that's pretty rare in Ontario is one that I've had a hard time getting a hold for my garden, is the Snowberry (Gaultheria hispidula), which rarely gets above 50 centimeters in height. The tiny little flowers give way to marshmallow-white looking berries that make you want to just squeeze them! The wood work of their minute trunk and branches is so intricate it makes me to imagine tiny fairies admiring these shrubs as though they were their own ‘Giant Sequoias.’ Don't be fooled by much larger non-native Snowberry shrubs sometimes for sale at mainstream garden centres. Sure it's a nice plant where it's native, but in the Carolinian Zone of Southern Canada, it's an ineffective non native, that should be growing where it is native.
Other spectacular shrubs I dig include (listed below from smaller to larger, W = wetter habitat):
- Wintergreen
- Labrador Tea
- Snowberry
- Fly Honeysuckle
- New Jersey Tea
- Bush Honeysuckle
- Common Elderberry
- Round-leaved Dogwood
- Spicebush
- Flowering Dogwood
- Blue Beech
- Buttonbush (W)
- Highbush Cranberry (W)
Yes, this is too many to write about so let's focus on one - Spicebush. Gorgeous clusters of bright yellow flowers cling to the branches in late April/ early May like brightly coloured granola clusters. These transcend into bright red berries, the size of a Goji berry. The natural chemical constitution (i.e. the aroma) of the long oval leaves attracts the female Spicebush Swallowtail Butterfly who lays her eggs on the leaves. Not too long after, caterpillars emerge, casually munching on the leaves (only at night - caterpillars roll themselves up tightly in a leaf during the day!), often undetected to humans. Spending the winters as cocoons, they do not metamorphose until the following late spring as the adult.
So this is the full meal deal when you invest in native shrubs; you get the beauty of the plant, the high function for the ecosystem, and the spinoff benefits for attracting wildlife. Take some time to get to know more shrubs. They are a fascinating and important features in our gardens, providing the middle layer of our creative efforts and when used in the proper ecological context, they can really contribute to bolstering our urban ecology. Oh, and remember, they are locally adapted so they are Climate (Smart) Brilliant