The Mexican bush sage has been blooming for a few weeks, and, like clockwork, it is proving to be a favorite nectar source for the Monarch butterflies heading south. With so many other nectar flowers to choose from in the fall, there is something they like about this salvia.
The Mexican bush sage is known botanically as Salvia leucantha, and true to its name, is from Mexico, as well as Central America. It is a short day- or long night-bloomer, starting in late summer and flowering through several frosts. The velvety purple spikes with white flowers are produced in abundance – you could easily harvest 100 flower stems for the vase. The gray-green foliage also provides garden interest, even if the plants aren’t blooming.
Not only is a magnet for butterflies, it is also a regular feeding stop for hummingbirds. You will find them headed for the white blooms emerging from the velvety purple calyces. The ideal site is full sun, though a little afternoon shade is tolerated. The soil should be very well drained, so plant on raised beds or amend heavy soils by adding compost or humus.
While preparing the soil, incorporate 2 pounds of a slow-release, 12-6-6-fertilizer per 100 square feet of bed space. Space the plants 24 to 36 inches apart, planting at the same depth they are growing in the container. Do not plant under street or floodlights as these bloom in response to the number of dark hours.
Give them supplemental water during long dry periods. In the fall, after significant frost damage, prune to the ground level and add a layer of mulch for winter protection. Feed as new growth emerges in the spring with a light application of fertilizer and then every six to eight weeks through September. The Mexican bush sage can be lightly pruned once or twice in late April and early June to increase the number of blooming stems for fall. Harvest several stems and tie with sprigs of rosemary for hanging in the kitchen.
The Mexican bush sage is mostly sold generically, but Midnight (dark purple flowers) and Kathiann Brown (dwarf lavender) and the similar Santa Barbara (dwarf lavender) are choice selections. Mexican Bush sage will easily reach 4 feet while the compact forms are less than 3 feet.
For companion plantings, consider the obvious, fall-blooming mums in the yellow color range. They fit the herb garden perfectly and partner well with rosemary, garlic chives and lavender. The fall-blooming forsythia sage, Salvia madrensis, produces huge yellow spikes and makes an incredible companion. Yellow marigolds and gold lantana also make choice partners.
The Mexican bush sage is perennial through Zone 7, which encompasses most of the Triangle, given perfect drainage and a blanket of mulch. But it is a worthy annual if you have a long enough growing season knowing it will not bloom until August. It is among the easiest of plants to root by cuttings or to propagate by division.
Spiky flowers create interest and excitement in the garden and the Mexican bush sage also provides nectar for butterflies and hummingbirds, and cut flowers by the dozens.