Low Light and High Humidity: Identifying Oedema

Figure one: Typical symptoms of Odema/Intumescence.

Figure 1: Typical symptoms of Odema/Intumescence.

Oedema or edema, also known as intumescence.  This physiological disorder usually appears during periods of low light – from now through the fall, winter and into the spring.  If you’ve noticed salt-like crystals, odd tumour-like growths or water-soaked spots on either side of your plant leaves this disorder could be the culprit (Figure 1). The disorder affects a wide variety of tropical plants and succulents.  It can also affect greenhouse crops such as lilies, cyclamen, sweet potato vine, geranium, begonia, petunia, calibrachoa, ornamental peppers and other Solanaceae family plants. Continue reading “Low Light and High Humidity: Identifying Oedema”

Summer School: Lessons learned from another hot, humid Ontario summer

Happy first day of fall! It was a dry, sweltering summer across Ontario, and I’ve heard from some growers that it was the most challenging summer they could recall in recent memory based on the heat alone.  Oppressive heat and humidity pack a punch that leaves everyone feeling sluggish – you, your staff and your plants.  While we won’t complain too loudly (winter’s coming!), learning from this year’s challenges will help in summers to come as we experience more extreme weather. Continue reading “Summer School: Lessons learned from another hot, humid Ontario summer”

Now’s the time to be proactive about poinsettia nutrition

If you’re producing poinsettias this year, you are probably just about finished with potting up your newly rooted cuttings. Keeping an eye on your crop throughout the production cycle will help to identify problems early, and allow you to correct the problem before it gets out-of-hand.   Consider this blog post your “cheat sheet” on identifying poinsettia nutrition related disorders. Continue reading “Now’s the time to be proactive about poinsettia nutrition”

Keep those cuttings cool!

cool point

Ensure your cuttings stay cool in the heat, so they grow into “cool” mature poinsettias!

Environment Canada has placed most of Southern Ontario under a Heat Alert for the next few days.  It’s the time of year for sticking poinsettia cuttings, and cuttings of any floral crop are susceptible to extreme temperatures.  Plants are just like people, crank up the heat and they put all their energy into just surviving the conditions, not forcing roots. Stressful conditions at rooting can lead to poor plant quality and cause defects that will be seen later in production like poor branching and leaf deformities. Continue reading “Keep those cuttings cool!”

Nutrient Deficiency Refresher

As we start to move into fall and winter flower crop production cycles, it’s a good time to go back through some basics about nutrient deficiencies.

No matter where you are in a cropping cycle, nutrition problems can be tricky to figure out.  The good thing is they can be differentiated from disease or pest issues based on a few key observations:

  • If the damage is uniform and crop wide, it’s most likely a nutritional issue
  • If the damage is localized or more random, it’s most likely a disease or pest issue

Continue reading “Nutrient Deficiency Refresher”

Supplemental Lighting Options for Bedding Plant Seedling Production

Happy spring!  With the season in full swing, we know that growers are busy this month.  I read an interesting article on the effects of supplemental LED lighting in bedding plants this week, and I’ve summarized it here with the key messages at the bottom of this post.  It seems like an appropriate article for the season, especially if you are starting to think ahead to how you might improve production for the 2017 spring season.

Much of the LED lighting research done in ornamental plants has focused on finding the best wavelengths for plant production.  This can vary based on the plant being grown, and the qualities desired.  Before we dive into the study, let’s review some of the reasons why you might consider LED lights from a plant production standpoint. Continue reading “Supplemental Lighting Options for Bedding Plant Seedling Production”

A Burning Question: Ethylene and Sulfur Dioxide Damage in the Greenhouse

I’ve had a handful of calls in the past few weeks asking me to identify poor air quality damage on spring bedding crops.  Even if you have never had problems, the following is a good refresher on why proper maintenance of greenhouse heating systems is important.

 Natural gas and propane are popular choices when it comes to heating a greenhouse.  The products of burning fuel are carbon dioxide (CO2) and water (H20); both compounds we know are good for your plants.  However, combustion is often (if not always) incomplete, and impurities such as carbon monoxide (CO), sulfur dioxide (SO2) and ethylene (C2H4) are also released leading to poor air quality if your heater is not properly vented.

These impurities can leave your crop looking a bit down (Literally! It’s called epinasty, see more below), and it can happen in as little as 24 hoursContinue reading “A Burning Question: Ethylene and Sulfur Dioxide Damage in the Greenhouse”