Photo credit: Mary Derrick, UF/IFAS Extension.
When many of our summer blooming plants start fading, yellow cassia, Senna bicapsularis, becomes a show stopper. Late fall and early winter is when it blooms and dazzles. The bright yellow flowers appear in numerous clusters at the tips of this many branched shrub. This makes for a stunning display in sunny areas of the landscape.
Yellow cassia grows to 8 to 12 feet in height and at least twice that in width. In the panhandle it often freezes back when we have a harsh winter. If that happens, prune it to the ground and it will come back the following spring and regain its previous size and beauty by late fall when it is ready to bloom. An advantage is that it is moderately drought and salt tolerant.
The flowers are attractive to bees for pollen although they are not attractive to butterflies as the flowers don’t produce much, if any, nectar. Yellow cassia serves as a host plant for some lovely butterflies. The cloudless sulphur, orange-barred sulphur and the sleepy orange all use cassia to rear their caterpillars. The shrub will rarely be heavily affected by a little herbivory from their caterpillars and will recover to bring you a stunning display the following year.
Photo credit: Mary Derrick, UF/IFAS Extension.
If you purchase a yellow cassia, check out the botanical name. Senna bicapsularis is what you want and not Senna pendula var. glabra which is a listed invasive plant species for central and south Florida.
For more information on Florida gardening:
UF/IFAS Gardening Solutions
Azaleas pruned late in the fall will have little or no bloom in the spring. Image Credit: Matthew Orwat
As fall approaches, our spring blooming shrubs such as gardenia, spirea and azalea begin to look unkempt and overgrown. That means it is time to give them a severe pruning to get them ready for winter, right? Not so fast, take a minute to understand the growth habit of each species before diving in with the pruning shears.
Many do not understand that annual spring azalea bloom could be sacrificed completely by pruning spring blooming azaleas at the wrong time.
Pruning traditional azaleas in the fall will result in a loss of spring bloom the following year because most bloom on previous years’ wood. This means that they flower on growth put on throughout the previous growing season. If a gardener removes the previous season’s new growth, they are removing the blooms as well.
So, when is the proper time to prune azaleas? The ideal time to prune is directly after the spring bloom. This will give the plant enough time to generate abundant new growth, thus maximizing bloom next spring.
Even the developers of the Encore Azalea, a new repeat blooming type, recommend pruning as soon after the spring bloom as possible to maximize bloom set for the following year.
For more information on pruning azaleas or on general azalea culture, please read the UF / IFAS publication Azaleas at a Glance or check out the Pruning Azalea page on Gardening in a Minute.
Gardenia, Image Credit Dan Culbert.
Gardenias don’t need much pruning except to remove any dead or non-productive wood, to help them remain bushy, and to remain the same size as other plants in the landscape. Choose a cultivar that will mimic the size of other shrubs, not one too large for the area. Pruning should be done as soon after the summer bloom as possible. Pruning after the beginning of fall will reduce the next year’s bloom production. Know your cultivar. Some cultivars of gardenia flower on new wood as well as old, while some flower on old wood only.
Regarding spiraea, prune after the bloom as needed. The closer to the late summer or autumn, the greater negative effect pruning will have on bloom quality since spirea set their bloom in early autumn.
I hope this article prevented a few pruning disasters as well as started a thinking process for the act of pruning your landscape plants.
Peach Drift® Rose blooming in Quincy at the UF/IFAS NFREC Photo: J.McConnell, UF/IFAS
Growing roses in the South can have challenges and many gardeners think that they are just too high maintenance to plant. Plant developers are aware of this opinion and have worked to develop low maintenance roses that can make a novice gardener look like a pro.
The trend in horticulture is to develop and release plant series where closely related plants have similar characteristics but offer some diversity such as different flower color and size. A new series that is performing well in North Florida is Drift® Groundcover Roses. Available with flower colors ranging from white, yellow, pink, apricot, to red. All exhibit a low growing habit and will remain under three feet tall and spread up to four feet wide. Flowers are born in dense clusters for most of the year, only taking a break in the winter months.
Although not completely disease free, these roses do show resistance to rust, powdery mildew, and black spot which are common problems with roses. Deadheading is not necessary, but can be done to increase bloom and keep plants looking tidy. One of the best characteristics of the Drift® Groundcover Rose series is that they don’t get very tall, so they fit in small spaces. If you are looking for incredible color in a sunny site with limited space give this series a try.
Although low maintenance, roses do still require some attention, for more information read Growing Roses in Florida.
Do you have camellia plants with flower buds that fail to open? Here are possible causes for this problem.
For more information on camellias, contact the UF/IFAS Extension Office in your County or visit http://edis.ifas.ufl.edu/ep002 to access the publication, “Camellias at a Glance.”
A new IPM guide is making it easier to grow five common southeastern shrubs. Growing five southeastern shrubs is now easier thanks to a free, new IPM resource from the Southern Nursery IPM Working Group.
IPM for Shrubs in Southeastern U.S. Nursery Production is a compilation of Integrated Pest Management (IPM) information for five major shrubs in nursery crop production in the southeast. This 175 page book covers sustainable management for insects, mites, diseases, and weeds for these shrubs, as well as nursery production information. This IPM resource was developed for nursery growers although professional landscape managers and collectors of these plants also will find the information valuable.
Individual chapters cover abelia (Abelia spp.), camellia (Camellia spp.), shrub rose (Rosa spp.), blueberry (Vaccinium spp.) and viburnum (Viburnum spp.). Each chapter provides comprehensive information on the species, primary cultivars and their nursery production. Major pests, diseases, weeds and abiotic disorders are presented for each genus along with sustainable management methods and tables listing labeled pesticides and fungicides by mode of action and site. An additional chapter discusses weed management in shrub production. Future volumes covering additional shrubs are anticipated.
Edited by Clemson University’s Sarah A. White and University of Tennessee’s William E. Klingeman, this free guide was developed by the Southern Nursery IPM Working Group, including University of Florida NFREC’s Gary Knox and Mathews Paret. The award-winning, multi-disciplinary group is composed of experts from universities across the southeast. This group formed in 2008 to develop and deliver educational programming to the southern U.S. nursery industry and Extension personnel. The team recently won the 2014 Bright Idea Award from the Friends of Southern IPM and Southern IPM Center.
This resource joins the tree IPM book previously released by this group, IPM for Select Deciduous Trees in Southeastern US Nursery Production. The tree IPM book is similar to the new resource in that it contains IPM information for insects, mites, diseases, and weeds of nine major tree crops as well as production information. Individual chapters cover birch (Betula spp.), cherry (Prunus spp.), crapemyrtle (Lagerstroemia spp.), dogwood (Cornus spp.), chinese elm (Ulmus parvifolia), magnolia (Magnolia spp.), maple (Acer spp.), oak (Quercus spp.) and redbud (Cercis spp.).
Both books can be downloaded free through iTunes (http://www.apple.com/itunes/) or each chapter is available as a free pdf through the Southern Nursery IPM Working Group website, http://wiki.bugwood.org/SNIPM. A limited number of hardcopy books were printed and distributed to authors. Thanks to the Southern Region IPM Center for their generous support to make this resource possible!