The forsythia are in bloom at our house, adding the first bright patch of color for spring. Forsythia are the earliest flowering shrub in the Denver area, at least as far as I can tell from meanderings through landscapes in the region. However, they are the first of many that are soon to come, with lilacs, viburnums, and prunus varieties being soon to follow. To have a good bloom season on these shrubs requires a little cooperation from nature, as a hard freeze or snow storm can zap the flower buds, which are much less cold hardy than the stems or leaves. There’s not much we can do about that, besides enjoy the show when nature allows for it. What you can do though is prune these shrubs at the proper time to encourage flowering. In the fall, landscape maintenance companies and homeowners often take the gas or electric-powered shears to all the shrubs in the landscape, and give them a nice shape for winter. Sadly this is the worst thing you can do for spring flowering shrubs (and shearing in general is a bad idea for most shrubs, but more on this in a future post). For shrubs that flower in spring, the flower bud is formed during the previous season, typically by mid-summer. So, if you prune those shrubs after the flower bud has formed, you are removing the next season’s flower display. The best time to prune spring flowering shrubs is once the flowers have faded, and before the real surge of new growth has begun. Once our forsythia have faded, we’ll prune them and share some photos and tips on how to prune your own (hint: it’s not with shears).
