Perennial Garden Care

Here are some tips on how to take care of your perennial garden.

• Loose, well-drained, loamy soil to which compost has been added is ideal in most regions.
• Fertilize with low-nitrogen, high-phosphorus fertilizer. Most perennials do not need heavy fertilization. A single application in spring (after the soil has warmed) is usually sufficient.
• Water deeply, especially during the first growing season. The soil should never be overly dry or wet. Avoid getting water on the foliage to avoid disease.
• Group plants that have similar water requirements.
• Mulch around plants to keep weeds to a minimum and retain moisture.
• Create a neat, clean edge between your lawn and flower bed. Use an edging tool or install permanent edging.
• Remove spent flowers to prevent plants from using their energy on seed production and to stimulate reblooming.
• Put plant supports in place early in the season, before plants get too big.
• Divide big plants when they are not in bloom. Spring and fall are usually the best times to do this.
• If your ground freezes, cover all your perennials with a protective mulch of compost or dry peat moss.
• Leave mulch on your perennial beds while ground is frozen until there comes several nights in a row with above-freezing temperatures. As you remove the mulch, add it to your compost pile.

In our region, where temperatures can dip, we have found a technique that allows the tougher perennials, such as alpines, to overwinter right in their pots.

• First, we cover the pots with Microfoam, a 1/2-inch-thick white foam blanket with plastic backing on both sides.
• Then we scatter a thick layer (about 6 inches [15 cm]) of loose peat moss onto the blanket and put another layer of clear plastic on top. Microfoam is a commercial product not generally available to home gardeners, but by substituting several layers of white spun fabric such as Remay, available at most garden centers, you can create the same effect.

Most containers don't have enough soil volume to insulate perennial roots from freezing when winter temperatures drop. Two or three weeks prior to freeze-up, transplant into the garden any perennials growing in all but large containers.