small flowering shrubs for my garden built on concrete

(Question)

Hi Master Gardener Team:

I have had a large mound of raspberry bushes and a dark green vine that produces tiny purple flowers. They have grown considerably thicker in what seems to be a symbiotic relationship. This was built on concrete and there is rotting wood/old planters under the “mound”. Any soil around this is damp and the rotten leaves seem to mulch with it as well.

I am in the process of cutting back about 1/3 and reshaping/expanding the mound/bed by approx 25 sq ft. I am using concrete stones, rocks and bricks as borders.

What are some relatively affordable shrubs or preferably flowering shrubs you would recommend. I want to make it more colorful leaf wise and possibly some blooms. I have just recently added 2 moonshadows to some of the cutback area.

Flattened area at front of pic to be filled im with shrubs/vines. Raised area at back is reconstructed wall (cant see in this pic) and current, trimmed back raspberry and vines (still plenty there).

Thanks in advance for your consideration.

(Answer)

There are many terrific shrubs for you too consider. There are two excellent Toronto Master Gardening Guides available for ideas for shrubs in full sun, Blooming Deciduous Trees and Shrubs, as well as one for various light conditions, Ornamental Shrubs for Various Light Conditions.

The following is a list of things to remember  when selecting various shrubs :

  • Hardinesss zone- make sure the shrub will survive in your  area
  • Lighting- Lighting is important to consider when choosing a flowering tree or shrub. For your new plant to thrive, it must have the right amount of light.
  • Soil Type- Is the soil acidic or alkaline? It may be necessary to amend your soil  in order to be sure your new plant will thrive in your garden. Also check to see whether your soil is clay, loam or sandy. The best approach is to choose the right plant for the right location.
  • Pruning and Maintenance- Shrubs must be watered regularly until established and also in times of drought. Top dress every spring with good compost, well-rotted manure, or quality organic fertilizer. Prune out branches that are dead, diseased, or damaged. Thinning out branches should also be considered as it improves air circulation and increases light penetration to the center of the shrub.

Have fun choosing and planting your new shrubs!