Irises vs. Mother Nature

By Bonnie J Nichols (Dallas, Texas)

There is always a standard joke in Texas:  “If you don’t like the weather – just wait a minute and it will drastically change.”  I really wish that statement was a joke; however, gardening in Texas (particularly iris gardening) is a challenge for us.

By RC Designer from Flickr

Our big challenge is that our weather has so many fluctuations, the irises remain in a confused state.  I hear iris gardeners from other states say “this has or has not been a normal iris bloom year”.   I’m not sure what “normal” for us is.

Gardening in Texas (and maybe throughout the south) issues include:

·       We do not encourage iris re-bloom because we have two choices.  If we continue to water the irises when the soil gets dry, we encourage bacterial rot because of our high humidity.  If we do not water in the summer when there is zero rain in July and August, we discourage re-bloom.

·       The second problem we face is in winter is that our ground does not freeze or have a constant cold temperature.  For instance, we experience 60-70 degree days and 30-40 degree days in January and February that bring early iris stalks that should not come until April. 

The second problem is what I would like to focus on in this article.  As I am writing, our weather forecast for the next three days is highs of mid-30 degrees and lows of 15-20 degrees.  We have early stalks on IBs and some TBs that as of tonight will be history.  We know we will lose more stalks that have not emerged from the foliage.  I have tried in years past to cover my irises with freeze cloth.  If anything, I made the situation worse because the freeze cloth kept the cold air in place.  Other iris beds that did not have the freeze cloth did better because there was air circulation. 

As dedicated iris growers as we all are……….you must look at the positive side.  The SDBs and aril breds will probably still bloom once we get to our last freeze date which is typically the third week in March.  If the TB season is a bust, the Louisiana and spuria bloom (which is much later) will be good.  Once this week of low temperatures passes, we are diligent about cutting out frozen stalks to discourage rot when the temperatures warm up.

One last note about spring and irises.  When the crocus bloom we fertilize our irises in Texas.  Crocus bloom is typically around Valentine Day.  When you apply granular fertilizer (we use 8-8-8), use caution and do not broadcast into the iris leaves.  When the rains come, the undiluted fertilizer will encourage rot.