June 2014 Culture

Perennial Solutions: Agastache Acapulco Deluxe Series By Paul Pilon

Agastache has been gaining in popularity in recent years. The increase in demand for this perennial is well deserved; after all, its aromatic foliage and showy flowers are appealing to bees, butterflies, hummingbirds and landscapers alike. If you are interested in adding an easy-to-grow perennial with a long-lasting blooming window into your production plan, consider the Acapulco Deluxe series from Green Fuse Botanicals.

The breeding of the Acapulco Deluxe series is a joint project between Thompson Morgan and Green Fuse Botanicals. There are currently three cultivars in the series: Carmine Red (crimson red flowers), Chiffon (lilac blooms) and Rose (rose flower spikes). Two additional cultivars (‘Acapulco Deluxe Peach’ and ‘Acapulco Deluxe Yellow’) are being added to the series beginning with the 2014 to 2015 growing season.

The leaves and flowers of Acapulco Deluxe are highly fragrant with a sweet licorice aroma. The series is compact, reaching an attractive 8 to 12 inches in height when in bloom. They perform well across USDA Hardiness Zones 5 to 10. Agastache is a fabulous summer perennial with a very long bloom time; consider using this one in the landscape or patio containers.

Propagation

The agastache Acapulco Deluxe series is vegetatively propagated from tip cuttings. Choose a propagation mix with good drainage and good aeration porosity. Moisten the rooting substrate prior to sticking the unrooted cuttings (URCs). Stick one URC into each cell. Rooting compounds are beneficial; spraying the cuttings with 1,000-ppm IBA soluble salts within 24 hours of sticking will improve the uniformity of rooting and decrease rooting times.

Place the cuttings under a moderate misting regime for the first few days of propagation. After the cuttings are acclimated to the propagation environment, provide enough mist to keep the cuttings turgid. Avoid over-misting as it will saturate the propagation mix and result in slow rooting and other cultural problems. When possible, it is usually best to propagate agastache under high humidity levels (90 percent relative humidity) with minimal misting. Gradually decrease the mist throughout propagation. Apply 100-ppm nitrogen beginning seven to 10 days after sticking the cuttings.

Agastache will begin to develop roots within seven to 10 days of sticking. The cuttings are usually rooted in less than three weeks with soil temperatures ranging from 68 to 75° F. Providing bottom heat, maintaining 70 to 75° F will promote faster root development. Many propagators pinch newly rooted liners at approximately three weeks after sticking to improve branching and performance of the liners after transplanting. Liners take approximately five to six weeks from sticking to become fully rooted and ready for shipping or potting.

Production

It is best to produce Acapulco Deluxe in 1-gallon or smaller-sized containers. They prefer to be grown in a well-drained medium with pH between 5.8 and 6.2. Many growing mixes will suffice; however, avoid ones with high water holding ability. Avoid planting the liners too deeply; the liners should be planted so the original soil line of the liner is even with the surface of the growing medium of the new container.

Agastache do not like having wet feet; over-watering them will lead to root rot and performance issues. Weak growth and yellowing are good indications that too much irrigation is being applied. When irrigation is necessary, water them thoroughly then allow the soil to dry moderately between irrigations. Although Mexican hyssop is drought tolerant in the landscape, do not allow mature plants grown in containers to become excessively dry.

They are considered light-to-moderate feeders. Nutrients can be delivered using water-soluble or controlled-release fertilizers. Growers using water-soluble fertilizers can apply 100- to 125-ppm nitrogen with each irrigation or use 200 ppm as needed. Controlled-release fertilizers are commonly incorporated into the growing medium prior to planting at a rate equivalent to 1.0 pounds of elemental nitrogen per yard of growing medium. Growing them under high fertility regimes generally results in soft growth and delays flowering.

Although this series branches well, it is often beneficial to provide a soft pinch one to two weeks after planting, once the plants become established. Large container sizes may require an additional pinch.

Acapulco Deluxe are naturally compact and should not require height management strategies. Undesirable stem elongation can often be managed by providing adequate spacing between the plants and growing them under high light levels. If the plants need to be toned, apply spray applications of 2500-ppm daminozide, 2500-ppm daminozide + 1250-ppm chlormequat chloride, 30-ppm paclobutrazol or 5-ppm uniconazole. In most instances, one application will be sufficient.

Insects and Diseases

Agastache can generally be produced relatively free of insects and diseases. Occasionally, aphids, spider mites, thrips and whiteflies may appear causing only a minimal amount of crop injury. Pythium and Phytopthora are the primary diseases growers observe. The occurrence of these pathogens can be reduced by planting the liners properly and with good irrigation practices. Other diseases to look for include Botrytis, downy mildew, Heterosporium leaf spots and rust. Growers can detect these insect pests and diseases with routing scouting programs.

Temperature and Scheduling

Flowering plants of Acapulco Deluxe can easily be done throughout the year. They do not have a vernalization requirement for flowering. If the plants are over-wintered, avoid keeping them overly moist and be sure to provide adequate protection during the winter months. They are day neutral and will flower under any day length. Growing agastache under high light intensities will increase the number of flowers, improve the coloration of the blooms and produce higher quality plants.

The best quality plants are produced when they are grown with night temperatures above 60° F and day temperatures above 65° F. The amount of grow time required depends on the production temperatures and the container size. At these temperatures, 4-inch pots take six to seven weeks to reach a marketable size, whereas larger 6-inch containers require nine to 10 weeks to flower.

Availability

The agastache Acapulco Deluxe series can be purchased from Henry F. Michell’s Co. (www.michells.com). They offer unrooted cuttings from Oro Farms and Innova Plant. Rooted liners can be obtained from Gro’N Sell (www.gro-n-sell.com), James Greenhouse (www.jamesgreenhouses.com), Meadow View Growers (meadowview.com), Pell Greenhouse Inc. (www.pellgh.com) and Hardy Starts (www.hardystarts.com).