Perennials and Blooming Cycles

Perennials are defined as plants that return in the garden 3 years or more from the same root base. Their bloom cycles vary from early to late season, short and long lived, but they can adapt, grow, and naturalize in places where annuals cannot, and once established are less overall maintenance.

When inspecting your garden site consider the amount of sunlight in the area, soil type, wind, rainfall, irrigation, and fertilizer. Most sun loving perennials prefer 6+ hours of direct sun; part-shade plants need 4-6 hours of sun, and shade tolerant plants require 4 hours or less. Perennials thrive in various soil conditions, but most prefer well-drained, nutrient rich soil, worked 10-12” deep. This can be achieved by adding 2-3” of organic matter, peat, compost, or manure. Then apply a slow-release fertilizer, such as Osmocote or Plant Tone at least once in the spring and again in late summer. After planting, cover the soil with 1-2” of organic mulch, such as pine bark or hardwood, being careful not to cover the crowns of the plants. The mulch will suppress weed growth and hold in moisture to keep the roots cool. Irrigate 1” of water once per week for the first growing season and your perennials will flourish.

During the growing season, be sure to remove spent flowers by deadheading/shearing. Deadheading will not only promote more blooms, but also increases stem strength to reduce staking, and will prevent insect and disease problems. Also try reducing weeds throughout the season by carefully spraying a non-selective herbicide such as Round Up, or applying a weed seed killer like Preen. Once perennials get too large for an area, or their bloom cycle declines, try dividing and transplanting. Do this the opposite season they bloom; mid-summer bloomers can be divided spring or fall. At the end of the season a hard fall frost will kill the tops of many perennials indicating that it is time to clean them up. Cut the stems and foliage back to just above the soil level. Leave your winter interest perennials up until next spring.

Suggestions for each garden condition as follows: