Sometimes it’s only a cool breeze, just the breath of relief from summer’s heat, like the first rush of puppy love. Invigorated, you rush around the garden to rake leaves, plant pansies and put out new mulch. If you’re lucky, though, that breeze soon becomes a gale, roaring and consuming everything in its path. That’s unconditional cold, and thankfully it turns perennial leaves brown so they can rest for a few weeks at least.
Caring for perennial plants is not complicated, but what you do at this point in the year is important. The longer you leave green leaves attached to the crown of the plant, the better. Even if they’ve begun to brown at the tips, like my husband’s cannas, resist the urge to chop them all the way down. Sure, it’s fine to trim the brown parts off if you can’t stand it, but leave the green until cold turns it crispy. When you cut old stems and leaves and stems off of perennials, do a good job and clear the area of snipped or fallen debris. Looks like you’re cleaning up the plants, but you’re also clearing the area of place where insects and diseases can spend the winter in comfort.
Consider the crown of a perennial plant as precious as a tiara crusted in diamonds and treat it right. Cut stems down to, but not into that mass at the center of your perennial. Likewise, work rotted mulches into the ground around the crown and spread new mulch up to it, but don’t smother it. Perennial crowns need good air circulation all year, but if you have just planted new starts and fear for their lives, cover the whole plant with a used plastic pot on very cold nights. If pests were a problem last summer, consider spraying the crown with an insecticide that contains clarified oil of neem to help suppress them. Neem is organic and an effective miticide, insecticide and fungicide.
If you’ve ever given love unconditionally and been spurned, you know how it goes: the warmth turns to ice and you feel withered. That’s a humanized version of what happens to perennials with the first blast of cold air strong enough to take them down. But those plants and your heart are stronger than they look on the surface, and both rebound, stronger and more beautiful with each coming year.