Baptisia Australis Blue False Indigo

culturec onnection perennial solutions Baptisia australis Blue False Indigo

Named for its one-time use as a replacement for true indigo in dyes, this perennial provides year-long interest as a backdrop for other plants or a standalone specimen.

aptisia is one of the most which was used to make blue dye. will usually have a signifi cantly By Paul Pilon reliable, long-lived and Baptisia provides four seasons lower germination rate compared Beasy-to-grow perennials of interest beginning in mid- to to fresh seed. Many growers use a in the landscape. These attributes, late spring, when foot-long spires hot water soak over night to soften combined with its striking garden of intense indigo-blue fl owers arise the seed coat and bypass the need appeal, has led to its selection as the above the attractive, trifoliate, soft for stratifi cation. Jelitto offers bap- Perennial Plant Association’s 2010 blue-green foliage. Following the tisia as Gold Nugget seed, which Plant of the Year. Its common name, impressive display of blooms, it is pretreated to help improve the blue false indigo, was derived from develops numerous 2- to 3-inch- germination rate and bypasses the its use as a substitute for true indigo long puffy seed pods that emerge need for stratifi cation. (Indigofera) from the West Indies, green and turn charcoal black as It is best to sow them in plug trays they ripen in the late summer or with large cell sizes (no smaller early fall. These seed pods remain than 72-cell). Sow one to two seeds well into the winter months and per cell when using Jelitto’s Gold provide winter interest sought by Nugget or fresh seed, and sow two numerous gardeners and land- to three seeds per cell when using scapers. Additionally, baptisia regular (untreated) seed. Do not attracts butterfl ies into the garden cover them after sowing; it is ben- and is resistant to deer feeding. efi cial to cover them lightly with It forms attractive shrub-like growing media after the radical clumps reaching 3-4 feet high and has emerged. Germination will up to 6 feet wide at maturity. Bap- occur over a period of two to three tisia provides a terrifi c backdrop for weeks with temperatures of 68-75° other perennials and groundcovers, F. From sowing, it will take eight to makes a wonderful specimen plant 10 weeks to produce a transplant- on its own or can be used effec- able plug when grown at 65° F. tively in small groupings, or native When propagating them from cut- or meadow plantings. Blue false tings, they require a light misting indigo is a native species of North regime for the fi rst seven to 10 days America and is commonly grown and will reach a transplantable size throughout USDA Hardiness Zones in six to seven weeks. 3 to 8. It grows best in full sun but will perform well in locations that Production receive light shade; avoid placing Baptisia are best produced in them under heavy shade as they large containers (one gallon or tend to require staking and may larger) and should be planted even not fl ower under these conditions. with the soil line of the plug it was previously produced in. Bareroot Propagation starting materials are also available Baptisia australis can be propa- and should be planted so the crown gated by seed or with vegetative is slightly below the soil surface. To tip cuttings. Germinating seed promote branching, pinch them can be challenging because of its prior to transplanting and again hard seed coat, providing variable several weeks later; it is not nec- results over time. The best results essary to pinch baptisia that was are obtained when using freshly planted from bareroot. harvested seed. Older seed can be Baptisia performs best in a used but will require stratifi cation growing mix with good water- or scarifi cation prior to sowing and holding characteristics and, more Photos: Walters Gardens, Inc. www.gpnmag.com January 2010 GPN 39 culturec onnection importantly, adequate aeration; many bark- per yard of growing medium or nitrate levels based growing mixes work well. Maintain the of 100 ppm under a constant liquid fertilizer media throughout the production cycle with program. Baptisia can be grown with slightly a pH between 5.8 and 6.5. They are moderate below-average amounts of irrigation. feeders requiring a controlled-release fertilizer Because of baptisia’s growing habit, it often at a rate equivalent to 1.0-1.2 pounds of nitrogen gets taller than growers would like in container production. There has been limited research done on controlling the height of blue false indigo, with some success when applying a drench of paclobutrazol (Bonzi, Piccolo or Paczol) at 12-18 ppm using the “watering-in” method. Spray Cultivate Business applications of paclobutrazol provide less height reduction than a drench in Your Community application and would require multiple applications using 30-45 ppm. Growth ® with America in Bloom regulator applications are most effective when applied early in production; begin applications when the plants reach 6 planting pride in our communities inches tall.

Insects and Diseases Compared to many perennials, the occurrence of insect pests and diseases are usually minimal with baptisia. The primary insect pests are spider mites, and the most common diseases are leaf spots, powdery mildew, rust and root rots. Routine scouting should be suffi cient to determine the presence of any pests or diseases. There are a number of good products on the market for controlling these problems once they are detected.

Forcing One of the most challenging aspects of growing baptisia in containers is bulking. From plugs, this is not a crop that can be quick cropped easily, as it takes a long time to fi ll out the container. When plugs are used, plant multiple liners in each con- tainer (at least two plugs per one gallon pot and more for larger sizes). Addition- ally, heavy fl owering will not occur until the plants are two to three years old. Therefore, when using plugs or liners, allow adequate time for bulking so the plant can build size and mature. In most cases, baptisia should be considered at Availability America in Bloom is a grassroots program least a two-year crop (planting this spring Baptisia Gold Nugget seed is available from connecting people with plants. More than for the following spring’s sales). Jelitto Perennial Seeds (www.jelitto.com); untreated 22 million people in nearly 180 communities However, full-fl owering plants of bap- baptisia seeds are available from various seed dis- have learned to plant pride. Find out how tisia can be achieved in a short period of tributors. Bareroot can be obtained from Walters to cultivate business in your community. time when using bareroot starting mate- Gardens, Inc. (www.waltersgardens.com). Plugs rials from Walters Gardens, Inc. Each and liners can be purchased from propagators bareroot contains fi ve to eight buds and throughout the country. GPN will easily fi ll out gallon-sized containers within weeks of planting. Paul Pilon is a horticultural consultant, Blue false indigo does require ver- owner of Perennial Solutions Consulting (www. nalization for fl owering. Spring-planted perennial-solutions.com) and author of Perennial bareroot does not require vernalization Solutions: A Grower’s Guide to Perennial Pro- as it received cold treatment in the fi eld duction. He can be reached at (616) 366-8588 or before the plants were harvested. After [email protected]. vernalization, baptisia can be grown at natural day lengths. Flowering will Visit www.americainbloom.org LearnMore occur in seven to eight weeks when For more information 614-487-1117 they are grown at 68-70° F or nine to 10 related to this article, go to Write in 138 weeks at 63-65° F. www.gpnmag.com/lm.cfm/gp011004

40 GPN January 2010 www.gpnmag.com