Purple leaf sand cherry shrub

Hi Master Gardener,

I live on the north east side of Toronto and I just bought a purple leaf sandcherry bush (prunes x cistena) during the end of season sales at a home hardware store. I hope to plant it in a full sun area in my yard but right now it’s still in its 2 gallon nursery pot. It’s a little under 3 feet tall. I have a few questions…

1) Since it’s already November, should I keep it in the pot outdoors or should I plant it? This week it is double digits so the ground I figure isnt frozen over yet. Would another option be keeping it in its pot indoors until the spring?

2) Is this the right time to prune it? It is quite scraggly and I would want it to grow bigger and fuller. Would this answer vary depending on if it is planted outdoors or kept indoors?

3) If I am to prune it, how would I do so? I’ve read some that say prune it all the way to the base in the autumn, and some say right above where a leaf grows after flowering in spring.

Please help! Thanks!

Thank you for contacting Toronto Master Gardners.

Prunus x cistena (Purple-leaf or purple sand cherry) is best grown in moist, organically rich, well-drained soils in full sun. It tolerates part shade, but for the best flowering and leaf colour plant in full sun. Good soil drainage is essential. Prune as needed after flowering.

Your shrub is a member of the rose family and is therefore susceptible to a large number of insects and disease pests, often leading to a shortened lifespan of about 10 years. Examples of possible problems include; Cankers, frost cracks, borers, aphids, scale, and Japanese beetles.

In terms of the best time to transplant, as a general rule, the best time to transplant most shrubs and trees is usually spring, when there’s more moisture in the soil, and plants are growing at a faster rate. You can also transplant during the fall once the plant is dormant and all its leaves have fallen off. However  since transplanting is traumatic for the plant and since it’s already November, you might consider waiting until the spring.

Luckily, your Purple sand cherry is cold hardy to Zones 2-8, so you might consider overwintering in it’s pot. According to garden expert, George Weigel, there are a couple of options to boost your plant’s winter survival odds.

1. “Store your potted woody plants next to a heated wall and especially any south- or west-facing walls that are brick or stone.”
2. “A second option is insulating the pots. You can do this by burying them for winter, by packing leaves, mulch or straw all around them, or by placing them in an even bigger container and filling the space between with straw or leaves.”
3. “The third option is moving them inside an unheated structure like a covered porch. A site that keeps the pots out of cold, drying wind and adds at least a few degrees more warmth can make the difference between death and survival. Give those plants just a little water a few times over winter to keep the roots from getting too dry.”

According to our own Toronto Master Gardner’s website, you should prune your purple-leaf sand cherry just after it finishes flowering.  This is because this shrub flowers on last years’ growth and pruning before then would reduce flowering in the current year.