Gardeners sometimes take on the challenge of growing a plant that is way outside their climate zone rating. We want to see if we can grow the plant and winter it successfully, or because the plant is so spectacular it is worth the extra effort required to care for it and protect it. Such plants include the tender roses, including hybrid tea roses and David Austin roses. If you have taken on such a challenge, you’ll now be thinking about how to get your David Austin rose through the coming winter.
David Austin roses have exquisite flower form, the perfume is wonderful, and the colours spectacular. With charming variety names like Lady of Shallot, Tess of the D’Urbervilles, and Wife of Bath, David Austins are popular wedding flowers, so if you are planning on staging a wedding in your yard they would be the perfect plant to add to the setting.
Successfully growing a David Austin rose in Manitoba begins with careful planting. The hole must be dug deep enough and wide enough to accommodate the roots without being crowded after they are spread out. Placing some bone meal, compost and rotted manure in the bottom of the hole before planting will get the rose off to a good start. The soil used to fill the hole should also be amended with these same ingredients to improve its texture and nutrient level.
There is usually a noticeable graft at the base of the plant because the David Austins available here are grafted onto other rootstock. The top of the graft should be covered by at least six cm of soil. After planting and watering well, a layer of mulch (such as dead leaves) should be added. This mulch layer should be five to six cm deep and will protect the soil around the feeder roots from getting too warm, and will conserve moisture. In Manitoba we generally plant tender roses in the spring to allow them to have a full growing season to get established.
David Austins were developed in England where the sun is less intense and where there is substantial cloud, so when they are grown here they do not need to be located in full sun, although like all roses they do require a substantial amount of direct sun each day. Protection from our intense midday sun is preferable.
In the summer the plants should be fertilized during the height of the growing season and supplied with a consistent supply of moisture. Carefully monitor for diseases and insects, and take immediate action if a problem is discovered.
David Austins are recurrent bloomers, so after the full flush of bloom in early summer, they will continue to produce flowers sporadically for the rest of the season. Each rose is fully double, with petals packed together in overlapping rows, and can be creamy and pure white, pink, yellow or deep crimson with shiny dark-green foliage.
The main challenge in growing David Austin roses comes at this time of year; they need a substantial amount of winter protection when grown in our Zone 2 or 3 gardens as they are typically rated as Zone 5. In late October, just before freeze-up, the plants need to be buried in a thick layer of mulch. The stems can be bent over and fastened either by using garden twine attached to a fastener securely placed in the ground or by weighing them down with bricks.
Alternatively the stems can be cut back to a height of about 15 cm before the mulch cover is put in place. The covering can be dry leaves, flax straw, or dry peat moss — the main point is that it should be dry to provide insulation against cold temperatures. To keep the mulch dry, some gardeners install a rose cone of Styrofoam while others construct a cover out of wood and plastic that will shed rain and snow and keep the mulch dry. The rose(s) should be well watered before the mulch is applied so that dehydration does not occur during the winter, but the watering should be done a couple of days before the mulch is applied so that the soil surface can dry somewhat so the mulch will not absorb too much moisture and lose its insulating value. One gardener I know grows David Austins in a group and surrounds them with a row of flax straw bales lying on their sides then fills this “box” with loose flax straw, covering the whole thing with a waterproof tarp securely held in place to withstand strong winter winds.
David Austin roses are slow to emerge in the spring so it is not a good idea to uncover the roses much before mid-May. The uncovering should occur after warm temperatures have arrived and be done gradually to allow the plants to adjust to being exposed to air and sun. Dead wood should be pruned only after the new buds are visible so that live wood is not inadvertently cut off. The mulch is removed to allow the soil to warm up but after this has occurred a layer of fresh mulch is again put in place for the summer.
Growing a David Austin rose in our area is no easy task but with some extra effort it can be done.