Plant Type: Shrub

Shrubs are the backbone of Pacific Northwest Gardens. We’re able to grow an incredible amount from all over the world. Evergreen to deciduous the choices are vast. We focus on mostly (but not all) low water species and many native western species. Shrubs are often much less thirsty than other plants and live for a long time if properly sited. They can sport amazing foliage or showy flowers.  From Manzanita to Ceanothus and even Grevilleas nothing makes a garden look more western. Our choice of shrubs is from years of experience growing them in our own gardens.

The best treatment leads to success

Treat all shrubs well when you plant. Dig a large hole and apply ample mulch and water to establish well. Do not let the shrub dry out completely until you are sure it is established and make a point to mulch each shrub. This is particularly important if you are creating a hedge or massing shrubs. Treating them all consistently well is the difference between continuity and chaos.

Pruning shrubs 101

The most daunting thing about growing shrubs is pruning. I try to include information about pruning each individual plant – but there are several rules that I adhere to when I prune a shrub that I am unfamiliar with. First, if you do not know the shrub let it bloom. Take note if it blooms on established wood from the previous season or if it grows and then blooms- an indication that it blooms on new wood. If it blooms on wood from the previous season – or ‘old wood’ then you can prune it directly AFTER blooming is done. That way you have less chance of eliminating bloom for the coming season and if it blooms on new wood you are safe too. Plants that bloom on new wood can be pruned in early spring some examples are Lagerstromia, Abelia, Indigofera. Once you understand this it makes pruning MUCH less intimidating. Make sure that you have very sharp pruners and it hurts nothing to sterilize them first. 1 TBS bleach to a bucket of water and a quick dip. Pruning can introduce disease so this is prudent.

New compact plants preclude pruning

Over the eons and more so lately nursery people have been selecting shrubs for more compact habits as well as vibrant bloom. Take advantage of these slower and smaller growing tendencies in the garden. Choosing the right size plant saves work in the future and eliminates the need to prune at all.

Many shrubs will morph into trees over time

In time many shrubs can pose as small trees and this should always be figured into a design. It is far easier and more natural to let a shrub  become arboreal than the tortured look and continual work of making it small. Some shrubs that go on to become trees in time are Osmanthus (many) Phillyrea, Camellias, Manzanita (many). Leptospermum.  Many reach tree like proportions in a decade or so. They may have their lower limbs removed to reveal shady planting space beneath and to accentuate the view of the bark which can be quite showy. They may also be trained to single leader to produce compact appropriately sized trees for courtyards and smaller gardens for a more formal appearance.

Topiary- a precise art

Topiary is an art that we dabble in at Xera. More than just torturing plants it is a process that takes a bit of planning and plant choice. It introduces a little discipline to the gardener in the form of regular maintenance and the effects are worth the effort. For the best effects and adaptability we use the tried and true forms of myrtle. They’ve been the subject of  topiary for eons and we know why. They take a lot of pruning with no harm. They live long lives in containers are drought adapted and we choose the cold hardiest cultivars. The flowers which are adorable are in perfect scale with the leaves,  Topiaries can introduce small amounts of formality in a garden and we love the way this plays in larger wild landscapes.

Rely on our soils own fertility

Shrubs in our climate and soils for the most part do not need fertilizer. In fact, over time I’ve seen more ill effects of overfertilization than I have seen benefits. Most often the plant is not getting enough water and the solution is a layer of mulch and a more consistent irrigation program. Often very drought adapted shrubs will react to added water in a dramatic way- Ceanothus, Grevilleas, Leptospermums, Arctostaphylos are genus’ that respond to water in a big way- in fact they react as if having been fertilized with no improvement to the soil at all and they explode in growth. Therefore, we recommend no supplemental irrigation for these genera when established but if they are slow to take off don’t be afraid to water, Irrigation requirements are in each description as well.

Shrubs- furniture for the garden

We need to shift our definition of shrubs. For too long they’ve been the tortured class of plants. The recent trend of grasses mixes excellently with shrubs but not if they are pruned into submission. Take the time to pick the correct plant for the site and be realistic. Plants grow fast in Oregon.

Climate Adapted Plants for Gardeners in the PNW