Wednesday, April 29, 2009

Trip Report: Muskogee Azalea Festival

My wife and I spent another weekend on the road.  This time we started by driving to the Azalea Festival in Muskogee, Oklahoma, which is about a 2 and a half hour drive from home.  I wasn't sure what to expect from this festival.  I had heard that the ice storm from December 2007 had damaged many of the older, well-established Azaleas and that they had been replaced by younger plants, which would not be mature for several more years.  I also wasn't sure what to expect in terms of Azalea-density.  I was thinking we would just drive around town and see 2 or 3 Azalea bushes in every yard.  I had heard that we should go to Honor Heights Park, but didn't really know any more than that.


Boy, were we surprised!  Honor Heights Park is a really beautiful space with a concentrated display of Azaleas.  There are also some really nice water features, including a wandering waterfall that comes down the hillside and pools a couple of times before eventually draining into the huge ponds of the park.  There are giant geese paddleboats that you can ride around the pond, if you are so inclined.

The park was crowded with locals and visitors alike, all enjoying the nice Spring weather and the beautiful scenery.


I was impressed with the number and diversity of Azaleas on display at the park.  I'm pretty sure I had seen all of the color varieties before, but the red variety was my favorite, a less common color for Azaleas.

Our weekend ended up being the "Weekend of Festivals."  We were also in Tahlequah, Oklahoma for the "Red Fern Festival" and in Siloam Springs, Arkansas for the "Dogwood Festival."  The latter two festivals are simply named after native plants that are in their most spectacular form during this time of year, but the festivals don't actually have anything to do with the plants, like the Azalea Festival.



Most of the Azaleas had the classic blossom like the pink Azalea pictured above.  Others had really long stamens and small petals, like the two pictures below.  They look wispy and remind me of the "Black Bat Plant."



We could tell that many of the Azaleas were youngsters that were just installed in the last couple of years.  They park will be even more breathtaking in 4 or 5 years, when they have had time to mature into larger bushes.  We had a great time and plan to visit again in the future!


Monday, April 27, 2009

Book Review: Oklahoma Gardener's Guide

I have been reading a book that my mom lent me, Oklahoma Gardener's Guide by Steve Dobbs.  I am really getting a lot out of the book, because of its focus on gardening in my location.  I would definitely recommend the purchase (or at least a library checkout) of a gardening book that applies directly to your region.  I'm sure there is probably one for every state in the country.

The introduction to the book tells about gardening in Oklahoma, including a short discussion on plant hardiness and ecosystems made up of similar climates and geographies.  That discussion got me to thinking and researching a little bit more.  Most of this post is about that subject.

The majority of the Oklahoma Gardener's Guide consists of plant profiles.  The profiles include information on how to grow these plants in Oklahoma, as well as different named varieties that are available and which are best choices for our location.  The profiles are divided up into several different categories:

  • Annuals

  • Bulbs

  • Ground Covers

  • Ornamental Grasses

  • Perennials

  • Roses

  • Shrubs

  • Trees

  • Vines

  • Great Plains Plants

A large appendix includes maps and information from the following topics:

  • Planning and Starting a Lawn

  • United States Ecoregions Map

  • Oklahoma Frost-Free Map

  • Oklahoma Freeze Map

  • Oklahoma Precipitation Map

  • Oklahoma Northern Counties Map

  • Perennial Ground Covers as Lawn Alternatives

  • Beneficial Insects

  • Other Plants for Oklahoma

  • Natives as Ornamentals

  • Oklahoma Public Gardens

  • Reference Publications of Interest

  • Glossary

  • Your Garden Plans

Discussion of Plant Hardiness

In addition to the USDA Plant Hardiness Zones map, Steve Dobbs includes a map of Ecosystems in the continental United States.  There are six ecosystems identified in the United States: Pacific West, Mountain West, Desert Southwest, Great Plains, Continental East and Humid South.  The last four of those ecosystems intersect in the center of Oklahoma.  The center of Oklahoma is a sort of "four corners," dividing the state into quarters.  Lucky for me, I live right in the center of the state.  This means that gardening outdoors can be a little tricky where I live.  The map below shows a much more detailed view of ecosystems in the US.

USDA Ecological Subregions map
USDA Ecological Subregions map.  This is a more detailed map than the one shown in the book,  but still demonstrates the diversity of Oklahoma's ecoregions.

Oklahoma is known for its extreme weather, usually in the form of severe storms and tornadoes.  But Oklahoma made national news at the end of 2007 when we were hit by a horrible ice storm that tore down many trees and left others severely damaged.  It is also not unusual to have fairly long droughts during the mid to late Summer, when much of the state is behaving more like the Desert Southwest, rather than the Humid South.  Temperatures in my home town range from 10 F to 105 F in an average year.

The USDA plant hardiness zone map was updated in 1990, dividing many of the zones in two (an "a" and a "b").  Those zones have been consistently used by growers to indicate the cold hardiness of plants for several decades now.  However, the map indicates only the lowest temperature that could be expected during the course of the year.  Steve Dobbs writes that a single indicator is not enough information to convey whether a plant will survive in your yard or not.  Just as you need to take into account how much to water a plant and what sun exposure it needs, you also have to consider the relative humidity required by the plant and the heat that it can endure.  This is often described by saying that a plant is drought hardy, but being able to withstand a week without rain is different than withstanding a month's worth of high temperatures above 95 degrees Fahrenheit.  This happens in July and August in Oklahoma.

As it is now, plants that are hardy in my zone (zone 7) are suggested for here as well as Delaware and New York City.  Clearly these are very different climates and the same plant would require different care in these two locations, assuming the plant could live in both places.

There is some discussion about the USDA creating a heat hardiness map that would indicate the maximum temperature that can be expected in a year.  This map would show most of Oklahoma hitting a maximum temperature of 105-110 F.

The American Horticultural Society has produced a US Plant Heat-Zone Map that categorizes locations based on how many days each year the temperature reaches above a threshold value (86 F).  On that map, the majority of Oklahoma is in heat zone 8, with 90-120 days above 86 F.  By contrast, New York City is in zone 4, with 14-30 days above 86 F!  Now all we need is for growers to start labeling their plants by heat hardiness.  For instance, a marigold plant might be hardy for cold zones 4-9 and heat zones 7-8.  I just made that up as an example, so don't get worried if you're trying to grow Marigolds in heat zone 6.  I don't really know where Marigolds are hardy.

Most people that have gardened for more than a year or so understand that there is more to satisfying a plant's needs than just matching it with a cold hardiness zone.  But the more information that becomes consistently available for all of the plants that we see, the better for all.

Friday, April 24, 2009

The Oklahoma Redbud

In honor of Arbor Day today, I am posting about one of my favorite trees native to Oklahoma.

Probably the most beautiful natural plant growing in the state is the Oklahoma Redbud Tree (Cercis reniformis).  [By the way, Cercis is pronounced Sur-sis.]  This post contains many pictures of this tree and only one of the pictures was taken more than 3 miles from my house - most of them are from within a couple of blocks.

Large Redbud Tree (Cercis reniformis) in my neighborhood.  Sadly, about a third of this tree was damaged and lost in the December 2007 ice storm, but it is still alive and blooming each Spring.
To me, this tree is tied to the part of our state history that most Americans know pretty well.  Oklahoma was first opened to settlers in a series of "Land Runs," where prospective owners lined up and waited for a gunshot before setting off to stake a claim to their future homeland.  [The final 30 minutes of the movie "Far and Away," starring Nicole Kidman and Tom Cruise, captures the moment in history.]

Beautiful Redbud tree (Cercis sp.) in another neighbor's yard.
My wife's family was involved in the Land Run of 1889 and claimed the land where my parents-in-law currently live, surrounded by dense woods.  Much of the land has been untouched and is in its pristine, natural state.  Last Spring, my wife and I wandered around on the land and dug up some of the Oklahoma Redbuds (Cercis renifomis) which grow there naturally and transplanted them to our house.  In our day and age, most everything I have growing at my house was started in a greenhouse or by some professional grower and transplanted to my yard.  These transplanted native trees are a little more special, knowing that they were never touched by human hands before me.  They are completely the artifacts of nature, with no human intervention.

A wonderful, old Redbud (Cercis reniformis) near our house.
[I should note here that we only transplanted two trees and did not destroy any ecosystems.  The trees seed very well and there are many more to take their place.  The balance of nature has not been disturbed.] :)

A beautiful, old Redbud (Cercis reniformis). Try to ignore the trash cans sitting under this tree.
When my wife and I went out on our Redbud transplanting expedition, my parents-in-law warned us that our transplants wouldn't survive.  In the 15 years they have lived there, they have tried relocating some of the trees from deeper in the woods to a location visible from their house.  They have never had a successful transplant.  That didn't bother us much.  We barely even got roots with our two 6-8 foot saplings, but both of them survived the transplant and are growing very well in our yard.

Oklahoma Redbud Tree (Cercis reniformis) blooms. This is one of the trees we transplanted from my wife's family's land to our yard in town.
The Redbuds in town start blooming in mid March, with the Redbuds outside of town following 2 to 3 weeks later.  My wife and I have observed this consistent phenomenon for the last several years.  We assume that it is attributable to the "heat island" effect, but I'm kind of surprised that the small city of Norman, Oklahoma would have such a strong affect.  [According to the US EPA website, a city with a population of 1 million people will be 1-3 degrees Fahrenheit warmer than the surrounding rural areas.  Norman is just about 100,000 in population.]

The blooms persist for more than a month and then fall away as the trees start to leaf out.  I wanted to add some more pictures to this post to show the variability in coloration and form of different Redbud trees.  There are wonderful examples all over town, but what better place to go than a college campus for beautiful trees and landscaping?  The University of Oklahoma is right here in my hometown of Norman, Oklahoma.

Redbud trees (Cercis sp.) on campus of the University of Oklahoma
Redbuds (Cercis sp.) planted along the length of the University of Oklahoma women's soccer field.
Redbud (Cercis sp.) blooms and hanging seed - University of Oklahoma campus
Redbud tree (Cercis sp.) covered in seeds and blooms across the street from us.
One of our transplant Redbuds (Cercis reniformis) beginning to leaf out.
There is a pretty large Redbud tree in our neighbor's yard, right next to our shared fence.  The tree overhangs our yard and sheds its seed.  We have quite a few little 3-4" saplings that come up every Spring.  I have transplanted several of them to pots to let them mature, while the others get mowed over.

Small Redbud tree (Cercis reniformis) that grew in our yard - about 4 inches tall.
After they have gotten large enough, I will give these little trees away to friends and family that want a Redbud tree.

Redbud (Cercis sp.) blossoms forming in clumps along the branches of a tree in our neighborhood.
I carried my camera around town with me for a couple of days and took pictures of about 50 different Redbud trees.  I was hoping to show the color variation in these trees, but the pictures don't quite show what I see with my own eyes.  Regardless, I have lots of beautiful Redbud pictures.  I was successful in documenting the different forms of trees that I have seen.  The older trees more closely resemble the native trees that my wife and I saw when we went hunting in the woods.  The newer trees that are being planted in many yards are nursery-grown and nursery-"improved" trees.  I don't know if the trees are actually different species or if the nursery does something to "improve" the trees.  They usually have much thicker trunks and the branches are more dense.

A nursery-grown Redbud tree (Cercis sp.). The form of this tree is very different than the ones you find naturally growing in Oklahoma.  It might be an Eastern Redbud (Cercis canadensis), but I don't know for sure.
Most of these nursery trees are really well shaped.  Some are not (below).

Two very funny looking Redbuds (Cercis sp.) growing in a neighborhood near my house.  The one on the right looks more like a Crape Myrtle than a Redbud.
The nursery-grown trees are beautiful, but I wonder if they will be much like the Bradford Pear Trees that are all over town.  The Bradford Pears have been improved for branch density so much that they are constantly splitting because they can't support their own weight.

The Redbuds that I see around town that are not Oklahoma Redbuds (Cercis reniformis) are most likely the Eastern Redbud (C. canadensis), which I see a lot at nurseries.  A couple of weeks ago I saw a new variety of the Eastern Redbud (Cercis canadensis) for sale.  It is called 'Forest Pansy,' and has shiny wine red leaves in the Spring, which turn green but keep the purple tinge during the Summer.  In Fall, the leaves turn yellow and orange like many other trees, while keeping some green and purple as well.  I imagine this will become a very popular tree.  You can read some more about the cultivar here.  After seeing one specimen at the store, I saw two planted at the Fort Worth Botanic Gardens over the weekend.  They had begun to turn green and I really liked the mix of red and green leaves.

Cercis canadensis 'Forest Pansy' at the Fort Worth Botanical Gardens
Another interesting species in the Cercis genus is Cercis siliquastrum, the Judas Tree.  This tree grows in the Mediterranean region.  It derives its common name from a supposed myth that states that this is the species of tree by which Judas Iscariot hung himself after betraying Jesus Christ to the Roman soldiers.  There is speculation that this name and the associated legend came from a mix up in translation, whereas the name should actually be "Tree of Judea," not "Judas Tree."  Since the tree grows in the region of the New Testament events, someone mistranslated and then a legend was born.  A motive was not established, but the tree was in the right place at the right time.

I hope you have enjoyed my Redbud pictures.  If you're interested in a little sapling, let me know!  I have several available.

For full disclosure, I must admit that I don't know the exact species of many of the pictures in this post.  The Cercis genus is composed of about 20 species of trees.  I have seen Redbud trees around town with varying colors (from bright pink to dark purple) and varying forms (from short and stalky to long and sparse branches).  However, I am not enough of an expert on this genus to pick out the different species.  I happen to know that the greenhouse grown trees have a shorter, thicker form than the ones that I find naturally growing in Oklahoma forests.  I also know that some of the color variation just depends on what phase of bloom the tree is in.  Before the buds open they are dark purple and the blooms turn lighter pink as the petals emerge.  I tried to label all pictures accurately.  When "Cercis sp." is used, I don't know the exact species.

Monday, April 20, 2009

Trip Report: Spring Festival at the Fort Worth Botanic Gardens

Last weekend my wife and I drove down to Fort Worth, Texas to visit the Fort Worth Botanic Gardens for their annual Spring Festival.  The festival is held in one of their prized gardens: The Japanese Gardens.

Bridge in the Japanese Gardens
For this post, I have chosen just a small selection of 21 pictures from the 300 photographs that I took on Saturday.  There is a link at the bottom of this post to my full photo album, which I hope you'll view, whenever you have time.

One of about 8 Japanese structures in the Japanese gardens
The FWBG is a large complex of gardens, including a conservatory of tropical plants, rose gardens, tree groves, Texas natives, production and exhibition greenhouses, water gardens, a cactus garden and many others.  The Japanese Garden alone is 7 acres, while only being a small portion of the grounds.

Japanese Maple (Acer palmatum) with pink seeds above branches
Rock Garden in the Japanese Gardens
The Japanese Gardens are kept by only 3 gardens and a host of volunteers.  I simply can't believe the amount of work that lies in front of those 3 workers everyday.  The grounds are well manicured and a wonderful place to stroll and relax.  I have to admit I spent the whole time snapping pictures, though.  I guess I'll have to go back for another visit.

Striking foliage and berries of Japanese Mahonia in the Japanese Gardens
Traditional Japanese dancers performing at the Spring Festival
For the Spring Festival, there are events throughout the day, including traditional Japanese dancers, Japanese flower arranging, bonsai exhibits and other crafts (such as origami).

Dutch Iris Ikebana - the art of Japanese flower arranging
Drooping Bonsai tree on exhibit at the Spring Festival
I was most excited about seeing the Japanese Gardens, the Conservatory and one of the greenhouses - the Begonia Species Bank.

Curator and collection of the Begonia Species Bank at FW Botanic Gardens
The Begonia Species Bank was created to prevent the loss of Begonia species.  Since Begonias are very common houseplants, the true, natural species are at risk of being lost to all of the hybrids that have been created for our viewing pleasure.  The FWBG Begonia Bank is a large collection of Begonias as well as a library and source of information on this very popular plant genus.

Rex Begonia hybrids in the Begonia Bank collection
We timed our trip to the FW Botanical Gardens perfectly, arriving on the weekend of the Spring Festival, as well as the annual Forth Worth Orchid Society's Orchid Show and Sale!

Prize-winning orchid at the annual Orchid Show and Sale
This event was held in the Garden Center, which is a very nice building in the center of the grounds, with rooms for meetings and events like this one.  There was one room setup with nice displays of orchids, including ribbons on those which had won prizes.  The range of sizes, colors, shapes and growth habits is just astounding.  I will never get over the diversity of the orchid family.

Another Orchid on display
In a larger neighboring room there were long rows of tables crowded full with orchids for sale.  The growers had come from as far as the Chicago-area and the plants were reasonably priced.  I found myself walking away with 4 plants - 1 full grown miniature and 3 seedlings.  I'll have to post on those orchids in the next week or so.

I love the tall petals of this orchid bloom. It looks horned.
Attached to the Garden Center is a tropical Conservatory.  It is about 2/3 the size of the OKC Myriad Gardens, which I have visited several times and blogged about here, here and here.  The collection contains quite a few plants from the Marantaceae (Prayer Plant) and Araceae (Aroid) families, which made me very happy.

One of the many Calathea zebrinas housed in the tropical Conservatory
An Aroid that might be Epipremnum pinnatum 'Cebu Blue'
Most of the FW Botanic Gardens are free and open to the public during daylight hours.  The admission price for the Conservatory is only $1!  The Japanese Garden ordinarily costs $2 admission and the other gardens are free.

Iceland Poppies (Papaver nudicaule) in one of the outdoor gardens
Overflowing container in the outdoor gardens
Waterfalls in one of the outdoor gardens
You could easily spend a full day exploring the outdoor gardens, or 2-3 days if you really wanted to be thorough.  We spent 6 hours at the FWBG on Saturday and most of that time was spent in the Japanese Gardens and the Conservatory.  We also enjoyed walking around the Perennial gardens and Rose gardens.  The Rose gardens are the oldest part of the FW Botanical Gardens, established by day workers during the Great Depression.

The Rose Ramp at the Fort Worth Botanic Gardens
Many different Iris in bloom in the Four Seasons Garden
Lupine were one of my favorite displays of color in the outdoor gardens
I would highly recommend a trip to the Fort Worth Botanic Gardens if you are within driving distance or happen to be in the area for other reasons.  It is a wonderful place to explore and there are so many different things to see.

To see many more pictures from my trip to the FWBG click on the image below.

Fort Worth Botanic Garden

Friday, April 17, 2009

Corner garden additions

Last week I wrote about adding some plants to our corner garden.  Over the last couple of weeks we have carefully selected some plants and added them in.  Our main criteria are:

  • Colorful,

  • Not weedy-looking,

  • Season-long interest,

  • Emphasis on Perennials or self-seeding Annuals.

The corner garden in it's current state. It looks much fuller than it will in just a couple of weeks, when the Daffodil and Tulip stems die back.  Japanese Maple (Acer palmatum) in the foreground.
We did purchase some annuals that do not self-seed, but for the most part we chose plants that adhered to these criteria.

African Daisy - Osteospermum hybrid 'Orange Symphony' before planting in corner garden.
African Daisies were the annuals of choice for this year.  First we spotted the 'Orange Symphony' variety with its purple centers.  We bought four of these plants, but two of them quickly died, before we were able to put them in the ground.  Thankfully, Home Depot has a 1 year warranty on all of their plants.  We took back the two dead plants and replaced them with two of the purple variety 'Soprano Light Purple.'  These bright, annual flowers are grown by Proven Winners, that has produced creamy yellow, white, purple and orange flowers, all with purple centers.  You can see the color varieties grown by Proven Winners here.

African Daisy - Osteospermum 'Soprano Light Purple' planted in the corner garden. The green clover shaped leaves in the top left corner and the purple clover shaped leaves in the top center are both Oxalis. Tulip, Daffodil, Daylily and Violet foliage are also in this picture.
A couple of days after planting the purple African Daisies (Osteospermums), we found some more plants to add to our corner garden, including a wonderful little silvery shrub from the genus Elaeagnus (possibly Elaeagnus pungens).  I planted the Elaeagnus in the corner and moved the Oxalis to the foreground of the bush to provide good contrast with the silver foliage.  The purple Oxalis has actually started blooming since I moved them.  Their blooms are light pink, but look white in the picture below, due to some extra reflection.  Notice that the purple African Daisies are also much lighter looking in this picture.

Silver shrub is an Elaeagnus (pungens?). The white blooms in front of the Elaeagnus are from the purple Oxalis lying in front of it.
I really like the silvery leaves of this little shrub.  It turns out that it is from the same genus as the Russian Olive Trees that I admired last May in Boulder, Colorado.  I wrote a little bit about them on my Desert Island Challenge post.  This shrub will provide great contrast to the purple foliage of the Oxalis planted in front of it and the cranberry red Barberry bush planted on the opposite side of the corner garden.

Rose glow Barberry bush (Berberis thunbergii v. atropurpurea), planted 2 years ago
The Barberry bush is not new.  We planted it two years ago and it is one of my favorite outdoor plantings.  The foliage is just stunning, with such a vivid color.  It immediately draws your attention when you look at the garden, even with other plants in bloom.  I highly recommend this bush.

Another new addition - Euphorbia longifolia 'Excalibur'
I have just recently become aware of a group of Euphorbias that can be planted as perennial shrubs in temperate climates.  Most people know of a couple of species of Euphorbias - The Poinsettia (E. pulcherrima) and The Crown of Thorns (E. milii) - but would be surprised to find that this plant is from the same genus.  I am preparing a much more long-winded post on Euphorbias that I will probably have ready in the next 2 weeks.  The tag of this Euphorbia says "Abundant flower heads emerge red and turn a brilliant yellow, highlighting the mounded blue-green foliage.  A superb accent plant for the mixed border or rock garden."  So far we're just enjoying the blue-green foliage, which is a nice addition to our garden.

Pink creeping Phlox (Phlox subulata) in the foreground with contrasting foliage colors in background.
We planted several pots of creeping Phlox in our corner garden a couple of years ago, but for some reason they had trouble getting established.  It was probably due to a hot dry spell when we didn't stay on top of watering.  Only one of our Phlox survived from year's past - a pink one.  My wife's favorite Phlox are the blueish purple color.  So this year we bought three really healthy purple Phlox plants and mixed them into our corner garden.  We will stay on top of watering these, and hopefully have more Phlox every year.

Newly planted Purple creeping Phlox (P. subulata) with Oxalis in bloom (small pink blooms) and small Rudbeckia plants.
Over a month ago I raved about some Rudbeckias called R. hirta 'Moreno.'  Well, I ordered three of these plants.  They aren't much to look at right now (see the little rosette just to the right of the Phlox above?), but hopefully they will mature nicely this year and then bloom next year.  If I take extra special care with them for two seasons, I hope that they will start to self-seed and I will have many more in the future.  I also ordered some seeds of the 'Cherry Brand' Rudbeckias, which are solid red.  I am going to start these seeds in the next week.

White Cyclamen planted in more open space on the right side of the garden.
Cyclamen are one of my favorite plants.  I couldn't resist getting a couple of these plants to add to the corner garden.  With amazing silver foliage and really unique blooms that look upside down, this just seems like the perfect plant.  Notice the difference in variegation of the leaves on the two plants I purchased.

White Cyclamen planted in front of green Oxalis.
I just realized there are Oxalis in 8 of the 11 pictures in this post!  We were given two varieties of Oxalis by a coworker of my wife a couple of years ago.  One is a green leaf variety with bright pink blooms.  The other is a purple leaf variety with a light pink bloom.  They have multiplied each year and are doing really well in our garden.  We will probably have to thin them out soon, assuming they continue to multiply at the same rate.

Another new perennial that we planted is a Mexican Petunia (Ruellia brittoniana).  This plant has long, strappy leaves that are deep green and produces pink-purple blooms that resemble a Petunia.  We planted this plant on the nearly-empty top tier of the corner garden.

Mexican Petunia (Ruellia brittoniana 'Katie's Pink') planted on top tier of corner garden.  Green Oxalis in the foreground.
I also transplanted some of our Irises to the top tier.  I'm not sure why we have neglected to plant more back there, but now it is getting hard to get back there to do any planting, since our flowerbed is filling out.

What do you think of the new additions?