Q: I just got my new deck finished and want to plant some perennials and ornamental grasses nearby. Is now a good time to plant?

A: Typically, perennials and grasses planted in the extreme heat of the summer will require extra care on a daily basis. This occurs for two reasons. First, regardless of planting time, all plants suffer “transplant shock” which is simply the shock of getting used to their new location and watering schedule. Second, the plant will undergo additional stress when planted in extreme temperatures or subjected to extremes of watering.

Generally, fall planting (late August through late October) is the preferred planting time recommended on the Front Range. This is because the air temperature is cooling down but the soil remains warm enough to encourage the plant to develop roots before winter. The plant focuses all its energy on root development, since flowering time has passed.

However, if you are unable to plant in the fall, the next best time to plant is spring. There are several exceptions to fall planting—plant ornamental grasses in the spring, as well as heat-loving perennials and shrubs like agastache and butterfly bush. These plants actually need warmer air temperatures to stimulate their growth. In addition, evergreens are better planted in the spring, since they lose water through their leaves all winter and this may lead to early decline if planted in the fall.

Q: My daylilies are two years old and have never flowered. What is the problem?

A: Since your daylilies they are relatively young, it is unlikely they need to be divided. Usually, after five or six years, daylilies do become large enough to be divided.

A couple of more likely reasons are they are not getting enough sun or water in their current location. Daylilies will tolerate partial shade, but prefer full sun to provide a profusion of blossoms. And while they can tolerate poor soils, they are happier in well-drained soils that have been amended with organic matter.

Early next spring, apply a complete fertilizer once, such as 10-10-10. Daylilies like to be watered at least once a week to a depth of eight to ten inches and need even more water during periods of minimal rain. Mulching can be very helpful in maintaining moisture, and is necessary to help newly fall-transplanted daylilies survive their first winter.

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This page updated:  August 7, 2008