This post was contributed to by Drs. Sarah Jandricic and Chevonne Dayboll.
Summer is in full swing, and so too are garden mums. As you get ready for the next few months, here are a few tips to keep your crop on track.
Drip line irrigation can be a more efficient way of delivering water and nutrients to outdoor crops.
Irrigation method matters!
There are plenty of options for irrigation in potted outdoor crops, but not all are created equal if you are trying to maximize your water efficiency. Overhead irrigation by boom, or sprinkler is not efficient if your pots are not spaced tightly. Canopy sizes in the later months of production may make this impossible, especially if you choose to go with final spacing when pots first move outside. These methods of irrigation can also lead to pots that are too dry (not watered) or too wet (over watered). Plants can only use water that makes it into the pot, so low volume drip line or tape is a more effective way to delivering usable water to your outdoor crops.
This post on poinsettia problems was contributed to by Drs. Chevonne Dayboll and Sarah Jandricic.
Okay, so Poinsettia don’t really get that many problems. But when issues arise, they can hit a crop fast and hard. Whitefly, Lewis mite, root rots, and nutritional issues can all quickly derail a quality crop.
Here’s a month by month guide on what you should be looking for to prevent small problems from becoming big issues.
This post was co-authored by Dr. Jeanine West, Flowers Canada Ontario’s Environment Specialist
Do you grow hardy mums and hydrangeas outdoors? If so, this blog post is for you! Flowers Canada Ontario, the Soil Resource Group and OMAFRA have collected data about fertilizer and water management in outdoor greenhouse crops over the last few summers, and have some updated production information for growers to think about over this year’s season.
How do you typically fertilize floriculture crops in your greenhouse? Based on how the plant performs? Maybe based on recommendations from your consultant or supplier? Do you do it the way it’s always been done? Do you know why it was always done that way? Continue reading “Considerations for fine-tuning your fertilizer program”→
Spring is here, and we know you’re busy! Here’s a quick but very important refresher on fertilizer injector maintenance. Ensure they’re working properly on a regular basis to avoid extra headaches.
How do I know if my injector is working properly?
Hopefully damage to foliage wasn’t your first sign things were a little off! Some things to remember:
The dilution ratio needed for each application should be known and adjusted as needed.
Remember that tracing dye in water-soluble fertilizers should never be used as an indicator of the actual strength of a fertilizer mixture.
If you are using multiple products or chemistries ensure they are compatible for tank mixing before running them through the injector.
If deviations greater than 5% from the expected setting occur, contact an irrigation specialist for assistance or repair. (But first, double check that math!)
Fertilizer injectors come in all shapes and sizes in the greenhouse.
There are two common methods to check if your injector is working as expected. Regular calibration is needed to ensure that an injector is operating properly. You should complete both methods listed here to ensure accuracy. Continue reading “A Reminder about Fertilizer Injector Maintenance”→
Forcing hydrangeas for Easter? Our friend Dr. Brian Whipker at North Carolina State University has released a great resource on managing nutrients to ensure your blooms are blue and not bluish-purple. Continue reading “Hydrangeas: Getting the (right colour) blues”→
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”→
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
It’s that time of year again, when baskets of Million Bells (Calibrachoa) are going up in the greenhouse. Here’s how to deal with and prevent some of their most common issues.
Iron deficiency in Calibrachoa. The resulting yellowing can look similar to symptoms caused by black root rot or nitrogen deficiency.
From a nutritional standpoint, the best thing you can is keep the pH of your calibrachoa in its ideal range; between 5.5 and 6.0. A pH higher than this can inhibit nutrient uptake, especially micronutrients such as iron.
Iron deficiency can be difficult to distinguish from other issues (like Black Root Rot – see below), but typically leads to yellowing of new growth. Leaves may only show chlorosis between the veins, or it may be spread throughout the leaf. This is different from nitrogen deficiency where yellowing occurs in the oldest leaves. If iron deficiency occurs, adding a chelated form of iron is best for uptake.
Yellowed plant growth (yellow circle) and dead plugs (orange circle) on a plug tray of Callibrachoa from black root rot.
Million bells are also highly susceptible toBlack Root Rot (Thielaviopsis) – I’ve seen this take out a good chunk of a crop. Symptoms include:
Stunting of foliage and roots
Plants in a tray will have uneven heights
black areas on roots
yellowing of leaves
Prevention is worth a pound of cure with this disease, as it is difficult to eradicate once established. Important steps to take include:
Proper Sanitation. To avoid an issue with Black Root Rot year after year, immediately dispose of diseased plants, limit water splashing, and sanitize benches, floors and used pots/plug trays. Always physically wash surfaces with a cleaner to remove organic matter, then follow up with a disinfectant such as KleenGrow (ammonium chloride compound).
Consider prophylactic applications of fungicides onplug trays. Products include Senator (thiophanate-methyl) or Medallion (fludioxonil). Preventative applications are an especially good idea if you’ve issues in the past. Adding bio-fungicides containing Trichoderma harzianum(e.g. Rootshield, Trianum) may also help.
Lowering your pH. This diseaseis significantly inhibited by a lower pH – between 5.0 and 5.5.
Manage fungus gnats and shoreflies, since these insects can spread Black Root Rot between plants. Treatments include nematodes, Hypoaspsis mites , or applications of Dimiln (diflubenzuron) or Citation (cyromazine).
If already established, rotated applications of Senator and Medallion may limit Black Root Rot, but are unlikely to cure it.
Aphids tend to be found on flowers and new growth of Calibrachoa.
Lastly, Million Bells are highly attractive to aphids. With baskets hung up in the greenhouse, they can be “out of sight, out of mind”, but regular monitoring is needed to prevent large aphid outbreaks. Place sticky cards directly in baskets, and routinely check plant material for aphid cast skins and honeydew.
Once aphids are detected (and they will be!), applications of Beleaf (flonicamid), Enstar (kinoprene) or Endeavor (pymetrozine) will usually take care of them. However, be aware that all of these insecticides take around 4-5 days to start causing aphid death.
Do you grow hardy mums and hydrangeas outdoors? If so, this blog post is for you! Flowers Canada Ontario, the Soil Resource Group and OMAFRA have collected data about fertilizer and water management in outdoor greenhouse crops over the last few summers, and have some updated production information for growers to think about over this year’s season.
