At more than halfway through July, some gardeners may be wondering if it is too late to put in trees, shrubs or perennials. After all, many garden centres have some very attractive prices at this time of year, as they try to clear out some of the extra stock they received in the spring. As long as the plant you are considering is healthy, it is not too late to add it to your garden. Remember, a neglected, half-dead plant is never a bargain, unless perhaps it is free.
In fact, this has been an ideal summer so far for establishing new woody plants and perennials. Although we had some hot weather in the spring, the mild temperatures and extensive rains that Edmonton has received recently are perfect for plants trying to develop their root systems. Even drought-tolerant plants need extra water in the first year or two after planting to help them become established, and extra rain saves gardeners the trouble of standing outside with a hose every couple of days. Mild temperatures also prevent plants with small root systems from being scorched by the sun.
Although spring is generally the best time to plant, most trees, shrubs and perennials can be planted throughout the summer. Many gardeners even recommend planting trees and shrubs in the fall, but that practise generally works better in climates less prone to early frosts than it does here in zone 3. However, as long as the plant has adequate time to develop its roots before becoming dormant in the fall, you are likely to have success with later plantings. During the winter, when the plant is dormant, it still requires some water, but usually cannot take it up from the frozen ground. Since this will be a bigger problem for a plant with a limited root system, special care should be taken to water recently planted plants into the fall, even if they appear dormant.
Even if a newly planted tree or shrub experiences some winterkill during its first winter, as our hardy cherry did, it is likely to do better in subsequent years, as it becomes more established. Although this seems like a setback, it will allow the plant an earlier start in the spring than if it was only planted that year, so summer planting can be a great idea.