Creating a Woodland Garden

A woodland garden of native species provides homeowners with the opportunity to have a low maintenance and environmentally friendly natural landscape that’s beautiful and attractive to wildlife. The beauty comes in a shady lush green envelope that’s punctuated by the colours of the spring ephemerals such as spring beauties, trout lilies and Virginia bluebells as well as later season bloomers such as blue-stemmed goldenrod and wild lupine. Plus some of our most beautiful flowering shrubs and trees are components of the woodland garden plant list. But don’t forget green is a colour and time spent in the green environment of the woods or your woodland garden is very calming and therapeutic. There is plenty of scientific evidence to support this.

Assuming that there are a number of trees providing shade (the woodland), there are a few fundamental characteristics to give consideration to when creating a natural woodland garden.

Pit and Mound

Pristine, old growth forests have an undulating soil landscape known as pit and mound topography. When large trees blow over in storms, the roots pull soil with them leaving a pit and when the roots eventually decay, that soil and resulting compost creates a mound beside the pit. A pit and mound topography establishes different soil and moisture conditions which provides opportunity for a greater diversity of plants to seed and grow. A flat site could not sustain near the diversity of flora. The pits will keep your woodland garden moist longer and reduce watering requirements. A replica of pit and mound topography can be created using a rototiller or a shovel. The pit should be 15 to 30cm deep and the mound a similar height and about a metre wide and two metres long. Vary their sizes, shapes, heights and depths somewhat and leave some space between them. Several pits and mounds would suffice in the average backyard of 15 by 20 metres.

Highly Organic Soil

Woodland plants grow in an organic/compost/humus rich soil environment created by the leaves that drop each autumn. Even twigs, branches and large tree trunks laying on the ground eventually decay and enrich the soil. This is important for a number of reasons including soil fertility, moisture retention and habitat for small and microscopic (mycrrohizae) living organisms. Humus is the be all and end all of healthy soil. Mycrrohizae are the nutrient and moisture accumulators of the woodland soil. Healthy soil is alive. The fungi that live in the humus/compost rich soil have a very important symbiotic relationship with woodland plants. They co-mingle with plant roots, which assists plants to receive and take up nutrients. Initially incorporating leafy compost into the woodland garden soil and then mulching with leaves every year is essential for growing native woodland plants. Basically just leave the leaves from your trees where they fall. A light top dressing of wood chips on the leaves holds them down from blowing winds (if that’s an issue in your garden) and adds more organic material.

Shade Levels

Deep in the woods, shade is a fairly constant condition but in backyard gardens it varies somewhat. Factors include the number, density and variety of trees your garden has, garden orientation and shade from buildings and fences. Even if all the backyards in your block are wooded, it will not be as shady as a natural forest. Locating the woodland garden under trees that are adjacent to the north side of a building could be a good start. If there is room, consideration could also be given to planting more trees or sun loving shrubs on the south and west boundaries of the garden site. Also, north facing slopes are great locations. Of course, these strategies may not be possible and you will have to make the best of your site. We would not recommend attempting to establish a woodland garden under just one or two trees but if that is your long term goal then step one is planting young trees and shrubs.

Wind Velocity

Wind is greatly reduced within a forest. Winds are diverted over the tree tops with only light winds reaching the forest floor (except perhaps in severe storms). This results in little impact on the understory plants and growing conditions. Wind dries the air and soil and reduces heat values. That is why the first 100 meters in from the forests edge is not considered quality forest habitat. Consideration should be given to reducing the impact of wind on your woodland garden. Planting a shrub wind break, using fences, buildings and garden orientation are strategies that could help. It would be very challenging to grow a woodland garden in a rural location with wide open fields surrounding it.

Soil Types

This is probably more important to the trees you may plant and grow than to the understory plants. Species such as Sassafras and Black Oak do best in sandy soils and struggle or perish in clay. Assuming that the woodland garden is being created under large mature trees, soil type is not a big consideration. Many woodland wildflower species, such as Trilliums, Jack-in-the-Pulpit and May Apple grow in either sandy or clay soils. The most important soil factor is its organic content. We believe this levels the playing field for woodland plants when it comes to soil types and conditions. Add compost when you plant and remember,,, mulch yearly with leaves.

Sod Removal

If the garden site has lawn it needs to be eliminated. Mechanically removing it with a sod cutter is an option but can be difficult because of tree roots and requires topping the garden with a good top soil. Spraying with a chemical herbicide is an option but requires the use of poisonous chemicals which we never use. The best method is smothering the lawn under cardboard covered by mulch. It’s recommended to do this months before planting but you can plant through the mulch and cardboard if need be.

Woodland Understory Flora

Many showy woodland wildflowers are known as “Spring Ephemerals”. They are long lived perennials that leaf out and flower in early spring before the tree canopy leafs out and shades the forest floor. They basically have to go through their annual life cycle quickly, taking advantage of the sunshine available before the tree leaves develop. Most spring ephemerals bloom for about a two week period, some amazingly early while there is still snow possible. After they have flowered and produced seed, they become dormant and withdraw valuable nutrients back into the roots. Survival through late summer, fall and winter lying dormant without leaves requires the storage of food. So spring ephemerals have evolved with special roots (bulbs, corms and rhizomes) to survive. Gardeners are most familiar with non-native exotic spring ephemerals such as Tulips and Daffodils.

Native ground covers, low maintenance carpets of green, flourish in the woodlands of Lambton County and are essential in the woodland garden. Patches of Mayapple, Ostrich Fern, Trilliums and Wild Ginger (see plant list and plant cards) are a special feature adding to the lushness and appeal of the woodland garden.

Other plants to consider are woodland shrubs such as Dogwoods, New Jersey Tea, Viburnum, Spicebush, Witchhazel, and Serviceberry for your garden. They are important to wildlife such as birds, butterflies and small mammals and provide some additional shade for the woodland perennials. We believe they are important functionally and esthetically and complete the woodland look and appeal.

There are also woodland perennials that flower in the summer and do not go dormant until fall. These include Woodland Asters, Sunflowers, Lilies and Goldenrods. Others are evergreen such as Hepatica, Virginia Waterleaf, Wild Strawberry and Woodland Sedges.

Sedges and ferns complete the woodland garden, so be sure to include them. Christmas fern is a good choice because it is an evergreen species.

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