Monday, April 25, 2011

Florida Hawthorns Are Hidden Treasures

I have never hidden my great love of hawthorns (Crataegus spp.).  I am unabashedly fond of them for a great many reasons and I have promoted their use in Florida landscapes for more than 20 years.  My love of haws comes from both their beauty and utility; traits that make them especially useful in landscapes designed for wildlife and for aesthetics.  And, given the large number of native species possible, there are excellent choices for nearly every setting likely to be encountered.

Hawthorns belong to the Rose Family, along with the plums, cherries, serviceberries, and crabapples.  Roses are revered for their beautiful 5-petal flowers, which are often present in the spring, and the production of nutritious fruit, generally high in vitamin C.  Florida’s hawthorns all produce white blooms; either solitary, in small clusters, or in large masses across the canopy.  The fruit are
Green haw: small flower clusters
variable in color, size, and time of year that they ripen. Like true roses (Rosa spp.), hawthorn fruit are often called “hips”.  Most are rather bland in taste, but an entire industry has been built in the South around the hips of the mayhaw (C. aestivalis) and its close relatives (C. opaca and C. rufula).   Hawthorn hips are also frequently available in natural food stores for use in teas and as nutritional supplements.

Despite their great ornamental beauty and practical uses, Florida’s hawthorns are not widely grown or available without some searching.  Over the past 20+ years, I have collected most of our species and incorporated them in the native plantings around the Pinellas County Cooperative Extension office.  Here, they can be seen as mature specimens and evaluated for use in your own landscape.  It is my hope that eventually the trade will make some of the less commonly grown species more widely available.

Hawthorns can be easily separated into groups by those that grow naturally in dry, sunny upland sites and those that prefer moisture and a bit of partial shade.  But over the years, I have learned that our wetland species can do exceptionally well in typical landscape conditions once established.  This should not be surprising, however, as many of our most commonly used natives, such as red maple (Acer rubrum) and dahoon holly (Ilex cassine), are naturally found primarily in wetlands.  Wetland haws just need some time to get established before they are required to make it without supplemental irrigation.

Littlehip haw: small, over-wintering fruit
Haws can also be separated  by those that hold their fruit into winter and those that don’t.  This is important to wildlife as the “winter-bearing” species generally provide food at a time when it is significant.  Haws which ripen in the summer and autumn come at a time when such food is abundant nearly everywhere.  Many of these are not extensively eaten by wildlife and eventually fall to the ground.  Winter-bearing species often go unused for months, but flocks of American robins, cedar waxwings, and even small warblers find and consume them by late winter – if not before.

Summer haw: large fruit
I have written extensively about hawthorns previously and have devoted a good number of pages to them in my recent book, Native Plant Landscaping for Florida Wildlife, so I won’t go into a long discussion here on the individual species.  What I thought might be most useful is to provide a table

(NOTE: If you wish to consult the table, use this link to the  FNPS Pinellas Chapter website, where you can download the newsletter containing the table and sign up to receive the newsletter electronically.  http://pinellas.ifas.ufl.edu/FFL/index.shtml )

 that clearly compares the traits most important in evaluating their use in home landscapes.  This table does not include every species present in Florida and is based on the taxonomy most commonly used currently.  This taxonomy, however, is changing – especially for the species most often called “summer haw” (C. flava). True “summer haw” is not now considered to be native to Florida and will likely be renamed and split into a number of closely related species including the one Dr. Wunderlin now calls C. michauxii.  Other taxonomists have put that species (common to our part of the state) under C. integra and have put others from north Florida under different names. Three different “summer haws” are present in the Extension landscape – I just don’t know yet what the new Latin names will be.  Regardless, I would encourage all of you to walk the grounds during late February and March while the haws are blooming to get a better idea of which ones you most prefer.

All haws are susceptible to a disfiguring disease, cedar- apple rust, which requires red cedar (Juniperus
virginiana) as an alternate host.  Infected cedars pass the spores onto haws (and other “apples”) where they complete their life cycle.  It is an annual cycle that goes back and forth each year between genera and it can be eliminated by breaking the cycle at either end during any single year.  If you have red cedar in your landscape or nearby (up to a mile away), use hawthorns with one eye out for the appearance of this disease.

Craig Huegel
hawthornhillwildflowers.blogspot.com

Since Arbor Day is coming up, we thought you  would like to consider planting one of these outstanding and lesser-known trees this year. The following species ARE available for sale at several nurseries who are members of AFNN (Association of Florida Native Nurseries):  C. aestivalis,
C. flava, and C. marshallii.  Here's the link to find  contact info for nurseries that carry these trees:

Those of you who have not yet purchased your own copy of Native Plant Landscaping for Florida Wildlife will be glad you waited - we are selling the book at our store with a freebie you will love! Buy the book from our store and you will receive a FREE sturdy canvas lunch bag perfect for the trail or the office: it's lightweight, with velcro closure at top, and fully washable. Sustainable and practical! Buy it here:       FNPS Store

Dr. Huegel will be at the conference next month to sign the books, too!


By the way, AFNN has a new name! They are now going by FANN, which stands for Florida Association of Native Nurseries. AFNN.org will stay the URL for a while longer; we'll let you know when it changes. Be a fan!

sue dingwell

No comments: