The Effect of a Micro-Climate

Strange things are always occurring in the garden. Or we think they are strange at first until we apply a little bit of logic to the situation! Over Thanksgiving I was visiting my in-laws. When we pulled up into the driveway I noticed something right away...the irises were blooming! Here in Tennessee we've had several hard frosts at this point already and even though these are re-blooming irises they should have gone dormant by now. The reason they did not go to sleep for the winter yet is because of the micro-climate that was created around them.

A micro-climate is a smaller area of a garden where the climate is different from the rest of the region. A number of factors can create a micro-climate including elevation, amount of sun/shade, wind exposure, and rocky material (these are just a few possible factors of many). The two factors that have effected the irises are the sun exposure and the proximity to rocky material. Stone and rock are heat sinks which means in this situation that they absorb heat and release it at night. The driveway and sidewalk, where the irises are, create a heat zone in the direct sun. As the days are sunny they warm up the stonework area then release the absorbed heat through the night which raises the nearby temperatures giving the irises a micro-climate to continue their blooming.

Gardeners can use the micro-climate effect to their advantage. A heat sink placed in the vegetable garden will help plants continue to grow longer into the fall and winter.  It's a good way to keep those greens actively growing for a few more weeks in fall or into winter.  Paving stones, bricks, gravel, natural rock and stone, and concrete blocks can all be used to either make stone walkways or raised beds that can be heat sinks.

Wind can be a major factor in the garden.  There are air currents in my yard that can cause the temperature to be significantly different just by moving a few feet away.  Windbreaks can be created by using evergreen trees, fences planted with vine plants, trellises, or walls can all alter the flow of the air and change micro-climates.  Deciduous trees can alter micro-climates by adding 3 seasons of shade or by breaking wind (go ahead you can laugh, trees do break wind).

Experienced gardeners will often try to do what we call "Zone Cheating".  This is where we challenge a plant to thrive in a heat zone that is at least one zone removed from where all the books say it should be!  Gardeners will take a zone 6 plant and grow it in a zone 5.  Or a zone 8 and grow it in a 7.  Sometimes the plants do fine without help but by adding in a few micro-climate factors like stone work or wind breaks the gardener can improve the chance of success.  (Here's the most recent U.S. Plant Hardiness Zone Map)

So they next time you think there's something strange going on in the garden examine the situation and use that micro-climate to your advantage!

A New Daylily and Iris Bed

Last week I put together a daylily and iris bed to cultivate and divide more plants for my little plant nursery.  Daylilies and irises are great plants for any garden since they offer so much for so little.  They grow strong without too much attention, enjoy the sun, and are tolerant various soils - which is good since this area has quite a lot of clay!

My daylily and iris bed is a small one but will be expanded onto later.  It's about 12 feet long and 4 feet wide.  I tilled it first - which was a challenge since it was on a slope, then raked it smooth and tried to remove any grass clumps left behind.  Ideally I would have located it on level ground but I wanted to keep the level areas of the yard open for three crazy children that need room to run.  Who knows when we'll need to turn the backyard into a baseball diamond, volleyball court, or kickball stadium?  Kids need room to run! The bed itself is leveled and sloped inward toward the hill to allow water to stay present in the bed a little longer.  Sloped areas have a tendency to dry out faster than you would like.



A month ago I picked up several highly discounted daylilies.  At $1 per pot it was hard to pass up.  I divided (more on dividing daylilies) the three pots of 'Fragrant Returns' into about 15 plants and one pot of 'Entrapment' into 4 and filled up a row.  I added a few more divisions from my garden including 'Primal Scream'

'Primal Scream'

(which is awesome) 'Crimson Pirate' and an iris called 'Solar Flare'.  There's still room in the rows but it's really amazing how fast it all fills in!


I used some old tomato stakes that i broke in half as plant markers for some of the daylilies.  I didn't have enough stakes to label them all so the re-purposed mini-blind tags were used for some.


I have quite a few unnamed irises that need divided so it won't take long before I need to add more area to this bed.  I may have to terrace the slope in some fashion to make it more usable for my growing needs!

'Crimson Pirate'

I'm continuing with my plans for hybridizing daylilies and irises.  I did some experimenting this year and successfully managed one cross between 'Crimson Pirate' and another daylily.  Most of my other attempted were foiled by the dry June weather we experienced.  I didn't label the cross and so I don't know the other daylily.  Currently I have two seedlings growing from that cross.  There may not be any value to that cross what so ever aside from the hybridizing learning experience. But you know, knowledge is valuable!

Re-planting the Self-Sowing Garden

A couple weeks ago I redid our self-sowing garden.  It was getting messy and too many weeds incorporated themselves into the garden.  I suppose they thought they could pass themselves off as desirable plants but their plans were foiled by May's Lowe's Creative Ideas Project!  The theme for this month was bulb plants.  Being one to never turn away from a project with plants I set out to Lowe's to have some plant buying fun.

I went to the store and collect several bulb plants, a few rhizome plants, and of course a few other assorted plants to fill in the garden.  Once I bought the plants I had to clear the area to plant them.  The self-sowing garden usually holds poppies, cosmos, coneflower, rudbeckia, salvia, and many others but had become overgrown with early spring weeds like chickweed.  I removed the weeds and replaced them with these beautiful plants that I brought home from Lowe's:

Peony 'Wladyslawa' - bloom just opening

Peony 'Wladyslawa' - in full bloom

Iris 'Clarence'

Iris 'Goldkist'

Iris 'Loop the Loop'

Asiatic Lily 'Matrix Orange'

Asiatic with huge blooms! That's my camera lens to the left.

I also added several marigolds which are great plants to help prevent damaging pests in the garden and a couple sweet potato vines to sprawl around as a border ground cover.  Here's the result!

The Asiatic lilies will grow and become more established after this year as will the irises.  In the spring this area will pop up with bulb blooms and eventually give way to the self sowing plants for summer creating a completely different effect for each season!

Oops, I Missed One!

In my last post about the irises of May in my garden I showed you several of my irises. Today a new one opened up that we just planted this spring. It's also a hand me down and has no real identity but it's nifty to look at!

I planted it with several others in front of the garden shed. (I really need to update you on it's progress soon.) So far this iris is the first of the new irises to bloom.

The Irises of May

May is a great time in the garden. The plants are full of growth, flowers are coming alive, the weather is good (except when it's not ;) ) and the irises are blooming! Lots of other things are blooming too but the irises are the standouts of the moment. The iris flowers even withstood the harsh rains of last weekend without losing their luster.

Over the last couple years we've gradually accumulated several different irises in the garden. I've only bought one (I like to brag about gardening cheap, I know you do too!), which was recently at the Tennessee Lawn and Garden Show, all the rest came from plant swaps or as hand me downs. The only down side to collecting irises from other people's garden is that you don't always know the cultivar names.  Irises can spread very rapidly and in a few short years one or two irises can turn into dozens! Irises can be divided to make more plants by taking the rhizomes and separating them after flowering through the late summer. Make sure you discard any rhizomes that appear to be rotten or hollow and when you replant the good rhizomes plant them shallow and partially above the soil. It's good idea to divide them every 2-3 years to maintain their vigor and keep your prized blooms blooming! Irises are tough plants so don't be afraid to divide them when needed.

Here's a picture of our birdbath garden two years ago with the first few irises that were planted. It wasn't much to look at then but the garden kept expanding.

And here's the same garden today. The irises flank the rustic birdbath. Behind the birdbath is a butterfly bush full of foliage after being cut back to about 18 inches in early spring.

And a close-up:

This purple iris is a couple shades of purple away from the irises in the birdbath garden. I've mixed it into the rain garden with some yellow irises that came from a plant swap.

In the side garden I've added these white Siberian irises. They are yet another great plant swap find swap and are my current favorite. The stems are smaller, more elegant and fit in much better with the garden when not in bloom than the bearded irises I have.

I also like the backdrop of Coral honeysuckle - I think the hummingbirds like it too!

The hummingbirds seem to enjoy the purple irises in the birdbath garden the most. The fragrance from those irises is a great way to attract the hummingbirds and other pollinators.

Irises in the Garden (Part 1)

Our first group of irises has just started to bloom.  The iris blooms are coming much later than last year due to the cold temperatures that have pushed everything back about nearly a month.  There are a just a couple types of iris here in my garden including the tall bearded irises, the Dutch irises, and some Siberian irises like 'Caesar's Brother'.  Right now we have one bearded iris and several Dutch irises in bloom.

Dutch iris or Iris xiphium are extremely easy to grow.  These I planted from a cheap pack of bulb bought last year.  They were mixed irises and contained at least three color types from blueish purple to purple to white.  These irises are showy but would have much more impact if planted in a mass grouping of similarly colored irises.

This purple Dutch iris is by my light post project from last year.  

We have more bearded irises than any other type.  This light purple one is in our rain garden area.  It's fairly plain but has this interesting spider veining on the falls which are the petals that fall downward.  (For more on the anatomy of an iris check out this page, great info!) This particular iris is not fragrant but another variety we have releases a strong grape scent throughout the garden.  That one should be opening up within the next few days.  Too bad I can't send the fragrance through a blog post!

Hopefully soon I'll be able to share the rest of our irises with you...if the cold weather relents!  Do you grow irises?

The Iris Garden

In our front yard is a triangular shaped area that for now I'm calling the Iris Garden.  In a week or so after the irises finish blooming I'll have to change the name to something else but for now the Iris Garden works!  I actually began this garden area as a winter color garden but soon realized that winter color should be interspersed everywhere and shouldn't be all by itself.  So I redesigned the garden to be what it is now.  At different times of the year this garden provides different types of interest.

The Trees

On each point of the triangle design is a tree. The largest of which is a Yoshino cherry that provides some powerful spring color with its white a pinkish colored blooms.  Two small redbuds anchor the other points.  They were transplants from my in-laws property.  Redbuds are tricky to transplant but with some care ( and a long enough root) it can be done! (This is best done when dormant.) Eventually the trees will shade the triangle enabling the garden to be converted to a part shade to full shade garden area.  That will be a few years down the road.

The Irises

The current main feature of the garden is the river of irises that flow down from the top point of the triangle.  These irises were all given to me by my parents who had a bunch of these lavender purple colored bearded irises.  Now we have a ton too!  These are highly fragrant irises and you can imagine with as many irises as we have in this garden the scent can be strong!  We have other irises in other gardens but I felt that keeping the same color scheme in this garden would give the maximum impact.

The Perennials

There are a few other perennials in this bed along with the irises.  Pretty much all of the perennials fit into the purple color category with variations in shade and tint allowing for a cool color blend.  'Caradonna' salvia is right next to the irises and will eventually become a second river that will re-bloom periodically through the summer. 'Purple Homestead' verbena is a spectacular groundcover that is perfect for this garden.  It doesn't like being constantly wet over the winters which makes planting in our sloped front yard perfect for it.  In the summer two Russian sage plants will flower.  One on the right side and the other on the left.  Surrounding the Russian sage on the left will be several purple coneflowers that have grown each year from seed with mother nature's help!  (We just let the seed fall where it may!)

The Annuals - err... Annual ...kind of....

We have one annual that grace's this garden: California Poppy.  It's orange and has nothing in common with the rest of the garden's colors.  That's OK since sometimes a unique and unusual color mixed in a sea of similar colors can make the garden pop a little more.  Our California poppies self-sow freely.  The foliage is a beautiful silver color reminiscent of an artemisia like 'Powis Castle'. This poppy can survive mild enough winters but for us it's more of an annual. 

It won't be long before the irises are finished blooming and the dividing and transplanting time will be here.  Everything is happening much earlier this year than it has in past years!

Already Time for Irises

THis first of the irises to bloom this year are the reblooming white irises we have in the Japanese maple garden. It's a small garden just to one side of our patio that ,of course, has a Japanese maple! It was a gift a few years ago to me for Father's Day. The reblooming white irises came home with me from a plant swap last two falls ago and bloomed again in the fall last year. White is nice but with all of the other iris colors that exist I wonder what potential hybrids could be made? That's one experiment that is on my list to try this year - hybridize my irises. I'll talk about the other (more colorful) irises I have in my garden later but for today we'll gawk at my white irises!

The white iris works very well when planted against this backdrop of Japanese maple leaves. The leaves on the Japanese maple have only been growing for a short time but once they fill in the combination should achieve its full effect. Many more white iris blooms are on the way.

Here is the garden from the other side. Not all the foliage is iris foliage. I've found that hiding spent daffodil foliage in and among the irises is a good way to disguise the fading daffodil foliage while allowing them to still gather energy from the sun.

Do you have reblooming irises in your garden? What do you use to hide the foliage of spring blooming bulb flowers?